## 统计代写|SPSS代写代考|Operational definitions

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Operational definitions

In designing a study, researchers will determine what variables they are interested in measuring. For example, they might want to measure self-efficacy, student motivation, academic achievement, psychological well-being, racial bias, heterosexism, or any number of other ideas. An important first step in designing good research is to carefully define what those variables mean for the purpose of a given study. When researchers say, for example, they want to measure motivation, they might mean any of several dozen things by that. There are at least four major theories of human motivation, each of which might have a dozen or more constructs within them. A researcher would need to carefully define which theory of motivation they are mobilizing and which variables/constructs within that theory they intend to measure. If a researcher wants to measure racial bias, they will need to define exactly what they mean by racial bias and how they will differentiate various aspects of what might be called bias (implicit bias, discrimination, racialized beliefs, etc.). If a researcher wants to study academic achievement, they might select grade point averages (which are very problematic measures due to variance from school to school and teacher to teacher, along with grade inflation), standardized test scores like SAT or ACT (which are problematic in that they show evidence of racial bias and bias based on income), or a psychological instrument like the Wide-Range Achievement Test (WRAT, which also shows some evidence of cultural bias). However, the research defines the variable and measures it will affect the nature of the results and what they mean. The way that researchers define the variable or construct of interest is referred to as the operational definition. It’s an operational definition because it may not be perfect or permanent, but it is the definition from which the researcher is operating for a given project.

Part of operationally defining a variable involves deciding how it will be measured. Many variables could be measured in multiple ways. In fact, for any given variable, there might be dozens of different measures in common use in the research literature. Each will differ in how the variable is defined, what kinds of questions are asked, and how the ideas are conceptualized. Researchers have a tendency to at times write about variables and measures as if they were interchangeable. They might include statements like,”Self-efficacy was higher in the experimental group” when what they actually mean is that a particular measure for self-efficacy in a particular moment was higher for the experimental group. As we advocate later in this chapter, most researchers will be well served to select existing measures for their variables. But the selection of a way to measure a variable is a part of, and should align with, the operational definition.

## 统计代写|SPSS代写代考|Random assignment

Another key term in research design is random assignment. In random assignment, everyone in the study sample has an equal probability of ending up in the various experimental groups. For example, in a design where one group gets an experimental treatment and the other group gets a placebo treatment, each participant would have a $50 / 50$ chance of ending up in the experimental vs. control group. This is accomplished by randomly assigning participants to groups. In many modern studies, the random assignment is done by software programs, some of which are built into online survey platforms. Random assignment might also be done by drawing or by placing participants in groups by the order the sign up for the study (e.g.s putting even-numbered sign ups in group 1 and odd in group 2).

Random assignment matters for the kinds of inferences a researcher can draw from a given set of results. By randomly assigning participants to groups, theoretically their background characteristics and other factors are also randomized to groups. So, the only systematic difference between groups will be the treatment or conditions supplied by group membership. As a result, the inferences can be stronger. We would feel more confident that differences between groups are due to group membership (or experimental treatment) when the groups were randomly assigned, because there are theoretically no other systematic differences between the groups. When researchers use intact groups (groups that are not or cannot be randomly assigned), the inferences will be somewhat weaker. For example, if we compare academic achievement at School $\mathrm{A}$, which uses computerized mathematics instruction, vs. School B, which uses traditional mathematics instruction, there might be lots of other differences between the two schools other than whether they use computerized instruction. Perhaps School A also has a higher budget, or students with greater access to resources, or more experienced teachers. It would be harder, given these intact groups, to attribute the difference to instruction type than if students were randomly assigned to instruction type.

Random assignment, though, is not sufficient to establish a causal claim (that a certain variable caused the outcome). Causal claims require robust evidence. For a causal claim to be supported, there must be: (1) A theoretical rationale for why the potential causal variable would cause the outcome; (2) The causal variable must precede the outcome in time (which usually means a longitudinal design); (3) There must be a reliable change in the outcome based on the potential causal variable; (4) All other potential causal variables must be eliminated or controlled (Pedhazur, 1997). Random assignment helps with criterion #4, but the others would also need to be met for a causal claim.
One distinction to be clear about, as it can be confusing for some students, is that random assignment and random sampling (described earlier in this chapter) are two separate processes that are not dependent on one another. Random sampling means everyone in the population has an equal chance of being in the sample. Random assignment means everyone in the sample has an equal chance of being in each group. They both involve randomness but for separate parts of the process.

## 统计代写|SPSS代写代考|Experimental vs. correlational research

The key difference between experimental and correlational (or observational) research is random assignment. Experimental research involves random assignment, whereas correlational research does not. We have described some of the advantages of experimental research in the kinds of inferences that can be made. Why, then, do researchers do correlational work? The simple answer is that lots of variables researchers might be interested in either cannot or should not be randomly assigned. Some variables should not be ethically or legally randomly assigned. If researchers already know or have strong evidence to believe that a treatment would harm participants, they cannot randomly assign them to that treatment. So, if a researcher wants to examine the effects of smoking tobacco while pregnant on infant brain development, they cannot randomly assign some pregnant women to smoke tobacco, because it causes known harms. Instead, they would likely study infants of women who smoked while pregnant before the study even began. Other variables simply cannot be randomly assigned. If a researcher wants to study gender differences in science, technology, engineering, and mathematics (STEM) degree attainment, the researcher cannot randomly assign participants to gender identities. Although gender identities may be fluid, they cannot be manipulated by the researcher. So, the researcher will study based on existing gender identity groups. That is the only practical approach. But people in different gender identities also have a whole range of other divergent experiences. People are socialized differently based on perceived or self-identified gender identities, they receive different kinds of feedback from parents, peers, and educators, and might be subjected to different kinds of STEM-related experiences. So, it would be difficult to attribute differences in STEM degree attainment to gender, but researchers might try to understand mechanisms that drive differences that occur along gendered lines.

Because many variables cannot or should not be randomly assigned, much of the work in educational and behavioral research is correlational or observational. Causal inferences are still possible, though somewhat harder than with experimental methods. Some of the most important and influential work has been correlational. Our point here is that experimental vs. correlational research is not a hierarchy-neither approach is “better,” but they offer different strengths and opportunities and have different limitations.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Generalizability and sampling adequacy

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Generalizability and sampling adequacy

As we have alluded to so far in this chapter, one of the reasons that sampling, and sampling bias, are important is about generalizability. Usually, when a researcher conducts a quantitative study, they hope to have results that mean something for the population. In other words, researchers usually study samples to find things out about the population. When samples are too biased or too unrepresentative, the results may not generalize at all. That is, in a very biased sample, the results might only apply to that sample and be unlikely to ever occur in any other group. Generalizability, then, is often a goal of

quantitative work. Very few samples’ results would generalize to the entire population, but researchers should think about how far their results might generalize. One way to assess the generalizability of results is to evaluate sampling biases.

Another issue in generalizability is related to sample size. How many people comprise a sample affects multiple layers of quantitative analysis, including factors we will come to in future chapters like normality and homogeneity of variance. But the sample size also impacts generalizability. Very small samples are much less likely to be representative of the population. Even by pure chance in a random sample, smaller samples are more likely to be biased. As the sample size increases, it will likely become more representative. In fact, as the sample size increases, it gets closer and closer to the size of the population. As a general rule, there are some minimum sample sizes in quantitative research. We’ll return to these norms in future chapters. Most of our examples in this text will involve very small, imaginary samples to make it easier to track how the analyses work. But in general samples should have at least 30 people for a correlational or within-subjects design. When comparing two or more groups, the minimum should be at least 30 people per group (Gay et al., 2016). These are considered to be minimum sample sizes, and much larger samples might be appropriate in many cases, especially where there are multiple variables under analysis or the differences are likely to be small (Borg \& Gall, 1979).

## 统计代写|SPSS代写代考|LEVELS OF MEASUREMENT

The data we gather can be measured at several different levels. In the most basic sense, we think of variables as being either categorical or continuous. Categorical variables place people into groups, which might be groups with no meaningful order or groups that have a rank order to them. Continuous variables measure a quantity or amount, rather than a category. There are two types of categorical variables: nominal and ordinal. Likewise, there are two types of continuous variables: interval and ratio. For the purposes of the analyses discussed in this book, differentiating between interval and ratio data will not be important. However, below we introduce each level of measurement and provide some examples.

## 统计代写|SPSS代写代考|Nominal

Nominal data involve named categories. Nominal data cannot be meaningfully ordered. That is, they are categorical data with no meaningful numeric or rank-ordered values. For example, we might categorize participants based on things like gender, city of residence, race, or academic program. These categories do not have meaningful ordering or numbering within them-they are simply ways of categorizing participants. It is also important to note that all of these categories are also relatively arbitrary and rely on social constructions. Nominal data will often be coded numerically, even though the numbers assigned to each group are also arbitrary. For example, in collecting student gender, we might set 1 = woman, 2 = man, 3 = nonbinary/genderqueer, $4=$ an option not included in this list. There is no real logic to which group we assign the label of $1,2,3$, or 4 . In fact, it would make no difference if instead we labelled these groups $24,85,129$, and 72 . The numeric label simply marks which groups someone is in – it has no actual mathematical or ranking value. However, we will usually code groups numerically because software programs, such as jamovi, cannot analyze text data easily. So, we code group membership with numeric codes to make it easier to analyze later on. In another example, researchers in the United States often use racial categories that align to the federal Census categories. They do so in order to be able to compare their samples to the population for some region or even the entire country. So, they might code race as 1 = Black/African American, 2 = Asian American/Pacific Islander, 3 = Native American/Alaskan Native, $4=$ Hispanic/ Latinx, 5 = White. Again, the numbering of these categories is completely arbitrary and carries no real meaning. They could be numbered in any order and accomplish the same goal. Also notice that, although these racial categories are widely used, they are also problematic and leave many racial and ethnic groups out altogether. For most of the analyses covered in this text, nominal variables will be used to group participants in order to compare group means. Another example of a nominal variable would be experimental groups, where we might have $1=$ experimental condition and $0=$ control condition.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Self-selection bias

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Self-selection bias

Humans participate in research voluntarily. But most people invited to participate in a study will decline. Researchers often think about a response rate of around $15 \%$ as being relatively good. But that would mean $85 \%$ of people invited to respond did not. In other words, compared to the population, people who volunteer for research might be considered unusual. Perhaps there are some characteristics that volunteers have in common that differ from non-volunteers. In other words, the fact that participants self-select to participate in studies means that their results might not generalize to non-volunteers. This bias is especially pronounced when the topic of the study is relevant to volunteer characteristics. For example, customer satisfaction surveys tend to accumulate responses from people who either had a horrible experience or an amazing experience-people without strong feelings about the experience as a customer are less likely to respond. The fact that people whose experience was neither horrible nor wonderful are less likely to respond biases the results. In another example, if a researcher is studying procrastination, they might miss out on participants who procrastinate at high levels because they might never get around to filling out the survey. Self-selection is always a concern, but particularly when the likelihood to participate is related to factors being measured in the study.

## 统计代写|SPSS代写代考|Exclusion bias

Researchers always set inclusion and exclusion criteria for a given sample. For example, a researcher might limit their study to current students or to certified teachers. Setting those criteria is important and necessary. But sometimes the nature of the exclusion criteria can exclude participants in ways that bias the results. For example, many researchers studying college students will exclude children from their samples. They do so for reasons related to ethical regulations (specifically, to avoid seeking parental consent) that would make the study more difficult to complete. However, it may be that college students who are not yet adults (say, a 17-year-old first-year student) might have perspectives and experiences that are quite different from other students. Those perspectives get lost through excluding children and can bias the results. It might make sense to accept that limitation, that the results wouldn’t generalize to students who enroll in college prior to 18 years of age, but researchers should consider the ways that exclusion criteria might bias results.

## 统计代写|SPSS代写代考|Attrition bias

Attrition bias is a result of participants leaving a study partway through. Most frequently, this happens in longitudinal research, where participants might drop out of a study after the first part of the study, before later follow-up measures are completed. In some cases, this happens because participants cannot continue to commit their time to being part of the study. In other cases, it might happen because participants move away, no longer meet inclusion criteria, or become unavailable due to illness or death. For example, in longitudinal school-based research, researchers might follow students across multiple years. Students might move out of the school district over time, and this might be more likely for some groups of students than others. Those students who move away cannot be included in the analysis of change across years, but likely share some characteristics that are also related to their leaving the study. In other words, the loss of those data via attrition biases the results.

Another way that attrition can happen is via participants dropping out of a survey partway through completing it. Perhaps the survey was longer than the participant expected, or something suddenly came up, but the participant has chosen not to finish participating in a single-time measurement. This is most common in survey research, where participants might give up on the survey because they found it too long. It may be that the participants who stopped halfway through share characteristics that both led them to leave the study and were relevant to the study outcomes. Again, in this case, the loss of those participants may bias the results.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Sampling and basic issues in research design

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Random sampling

In an ideal situation, researchers would use random sampling. In random sampling, every member of the population has an equal probability of being in the study sample. Imagine we can get a list of all first-year college students in the United States, complete with contact information. We could randomly draw 250 names from that list and ask them to participate in our study. We are likely to find that some of those students will not respond to our invitation. Others might decline to participate. Still others might start the survey but drop out partway through it. Therefore, even with a perfect sampling strategy designed to produce a random sample, we still face a number of barriers that make a true random sample almost impossible. Of course, the other problem with this scenario is that it is nearly impossible to get a list of everyone in the population. Random sampling is impractical in research with human participants, but there are several other strategies that researchers commonly use.

## 统计代写|SPSS代写代考|Representative (quota) sampling

Quota sampling method selects samples based on exact numbers or quotas of individuals or groups with varying characteristics (Gay, Mills, \& Airasian, 2016). We also call this sampling method representative sampling. Many U.S. federal datasets are collected using quota or representative sampling. In this sampling strategy, researchers set targets, or quotas, for people with specific characteristics. Often, those characteristics are demographic variables. For example, some federal education datasets in the United States use the census to determine sampling quotas for the combination of race, sex as assigned at birth, and location. These quotas are usually set to be representative in each demographic category. For example, the U.S. Census showed that Black women comprised $12.85 \%$ of the population of Alabama (U.S. Census Bureau, 2017). A researcher with a goal of 1,000 participants from Alabama might set a quota of 129 Black women for that sample (taking the population percentage and multiplying by the target sample size). The researcher would then intentionally seek out Black women until 129 were enrolled in the study. The researcher would set quotas for every demographic category and then engage in targeted recruiting of that group until the quota was met. The end result is a sample that matches the population very closely in demographic categories. However, the process of producing that representative sample involved many targeted recruiting efforts, which might introduce sampling bias. However, this method is widely used to produce samples that approach representativeness, especially in large-scale and large-budget survey research.

## 统计代写|SPSS代写代考|Snowball sampling

Another method of accessing population that is not easily accessible or hard to reach is snowball sampling. Examples might include members of a secretive group, people with a stigmatized health issue, or members of a group subject to legal restrictions or targeted by law enforcement. A snowball sample begins with the researcher identifying a small number of participants to directly recruit. That initial recruiting might involve relationship and trust building work as well. For example, if a researcher was interested in surveying undocumented immigrants, they might find this population difficult to directly reach because of legal and social factors. So, the researcher might need to invest in building relationships with a small number or local group of undocumented immigrants. In that example, it would be important for the researcher to build some genuine, authentic relationships and to prove that they are trustworthy. Participants might be skeptical of a researcher in this circumstance, wondering about how disclosing their documentation status to a researcher might impact their legal or social situation. It would be important for the researcher to prove they are a safe person to talk to. After initial recruiting in a snowball sample, participants are asked to recruit other individuals that qualify for the study. This is useful because, in some circumstances, individuals who are in a particular social or demographic group might be more likely to know of other people in that same group. It can also be useful because, if the researcher has done the work of building relationships and trust, participants may be comfortable vouching for the researcher with other potential participants. This approach is used in quantitative and qualitative research. One drawback to snowball sampling is it tends to produce very homogenous samples. Because the recruiting or sampling effort is happening entirely through social contacts, the participants who enroll in the study tend to be very similar in sociodemographic factors. In some cases, that similarity is acceptable, but this only works when the criteria for inclusion in the study are relatively narrow.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Benefits and compensation

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Benefits and compensation

Benefits and compensation are two very different things. Benefits are things participants gain by being in the study. In the above example about medical treatment, the benefit might be a reduction of symptoms or being cured of a condition. In educational research, benefits might be things like improved curricula or an increased sense of community. Benefits must be real and likely to occur for individual participants. Some studies have no known direct benefits for participants. The outcome of the study might be unlikely to benefit participants directly, but will advance the state of knowledge on some topic. Such studies are still acceptable under the principle of beneficence so long as the study presents no more than minimal risk.

Another element of many studies is compensation. There is no requirement in any regulations that a study offer compensation, but it is often included to improve recruitment efforts or to engage in reciprocity with participants. Compensation often takes the form of monetary payments (e.g., $\$ 5$for taking a survey, or entry into a drawing for a$\$100$ gift card for participating in a study). Compensation can also involve an exchange of goods or services (e.g., entry into a drawing for a video game system, or a pass for free gym access). In some cases, compensation might also take the form of academic credit, such as gaining extra credit in a course for research participation. Course credit is often trickier because compensation must be equal for all participants, and courses often have very different grading systems. Moreover, typically, any offer of course credit must be matched with an alternative way to earn that course credit to avoid coercion. We will discuss compensation more in the coming chapters as it relates to sampling strategies, but compensation (or incentives) is allowed, so long as the amount is in line with the requirements of the study.

## 统计代写|SPSS代写代考|Confidentiality and anonymity

In the vast majority of cases, data gathered from human participants must be treated with strict confidentiality. That means that researchers take reasonable steps to secure the data, like storing the data in a secure location, storing them on an encrypted drive, transmitting them via a secure means. It also means that researchers take special care to protect identifiable information like names, ID numbers, ZIP or postal codes, IP addresses, and other potentially identifiable information. In some uncommon cases, researchers might not be able to guarantee confidentiality, perhaps because of the nature of the methods (for example, group interviews, where researchers cannot guarantee that all participants in the room will maintain confidentiality), the nature of the participants (like interviews with school superintendents where it might be difficult to mask their identities adequately), or other factors. In those cases, participants should be informed of the risk of a loss of confidentiality, and benefits should outweigh that risk. However, in any case where it is possible to do so, researchers must maintain the confidentiality of their data.

An additional layer of protection for participants’ identities is anonymity. Anonymity means that even the researcher does not know the identity of the participants. It would be impossible for the researcher or anyone else to determine who had participated in the study. This means the researcher has collected no potentially identifying information. Anonymity is often possible in survey-based research, where participants’ entire participation might occur online via an anonymous link. In other kinds of research, anonymity might not be possible. In online research, one important setting to check is whether your survey software collects IP addresses by default, as those data are personally identifiable. Most survey systems allow researchers to disable IP address tracking so that data can be treated as anonymous. Anonymity lowers the risk to participants because even if the data were to be breached or accidentally exposed, the identity of participants would still not be known.

## 统计代写|SPSS代写代考|Institutional Review Board processes

In the United States, research is reviewed by a group known as the Institutional Review Board (IRB). IRBs are typically located within an institution, like a university, though sometimes an institution might rely on an external IRB. IRBs are usually comprised mostly of researchers, though regulations do require a community member representative and other non-researcher representatives for certain kinds of study proposals. IRBs are diverse and differ somewhat from institution to institution. Their specific procedures will also vary, though all will comply with the Common Federal Rule. Because of this

variation, researchers should always consult their local IRB information before proposing and conducting a study. In general, though, most IRBs follow a similar process.
First, researchers must design a study and describe that study design in detail. Most IRBs provide a form or questionnaire to guide researchers in describing their study. Typically, those forms ask for details about the study purpose, design, and who will be conducting the research. They will also ask about risks and benefits, as well as compensation. IRBs typically require researchers to attach copies of recruitment materials, consent documents, and study materials to the IRB so that reviewers can evaluate the appropriateness of those documents. IRB review falls into one of three categories: exempt, expedited, and full board. There is much variation in how different IRBs handle those categories, but typically exempt proposals are reviewed most quickly. Exemptions can fall in one of several categories, but are usually no more than minimal risk and involve anonymous data collection. Expedited applications are often reviewed more slowly than exempt because they require a higher-level review than exempt applications. There are multiple categories of expedited review in the Common Federal Rule as well, but often school-based research can qualify as expedited, depending on the specifics of the study. Finally, full-board reviews will be reviewed by an entire IRB membership at their regular meetings. Most IRBs meet once per month and will usually require several weeks of notice to review a proposal. As a result, the full-board review can take several months. Regardless of the level of review, it is very common for the IRB to request revisions to the initial proposal to ensure full compliance with all regulations. When planning a study, it is a good idea to plan in time for the initial review and one or two rounds of revision, at a minimum.

We have avoided being overly specific about the IRB process because of how much it varies across institutions. However, when planning a study, talk with people at your institution about the IRB process. Read your local IRB website or other documentation, and always use their forms and guidance in designing a study. Once your IRB approves the study, recruiting can begin. Researchers must follow the procedures they outlined in their IRB application exactly. Any deviations from the approved procedures can result in sanctions from the IRB, which can be quite serious. However, in the event a change to the procedures is necessary, IRBs also have a process for requesting a modification to the originally approved procedures. In most institutions, modifications are reviewed quite quickly.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|The common federal rule

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Justice

Finally, the principle of justice has to do with who should bear the burdens of participating in research in relation to who stands to benefit from research. In the Tuskegee study, Tuskegee was not selected because the population there stood to benefit more than other areas from any potential findings. Instead, researchers selected Tuskegee as a site for the study because it was remote and largely isolated, and because its residents were low income and Black. That meant that it was unlikely that participants would seek or receive any outside medical treatment, and it also meant the researchers could operate with little or no scrutiny. This is an unjust rationale for selecting participants. Doing research with marginalized or vulnerable communities should be limited to those cases where those communities will benefit from the results of research. In a related issue, it also means that research with captive groups like prisoners should only be done if the research is about their captivity. There is another side to this question, too, because there is a history of some fields of research having almost exclusively White, or wealthy, or men participants. This is particularly problematic in fields like medical research, where treatments might affect different groups of people in different and sometimes contradictory ways. However, federal guidance, relying on the principle of justice, requires the adequate representation of women and people of Color in research.

## 统计代写|SPSS代写代考|The common federal rule

These three broad principles are explained in the Belmont Report but did not have the force of law. Following the completion of the Belmont Report, federal agencies wrote regulations to enforce the three major principles. These became encoded in the Common Federal Rule. Called the common rule because it is a set of regulations common to all federal agencies, 45 CFR part 46 is the federal regulation governing all federally funded human subjects research except for medical trials. Because of the differences between medical and social/behavioral research, there is a different common rule for medical research (21 CFR part 56). Research other than medical research is overseen by the Department of Health and Human Services’ (DHHS) Office of Human Research Protections (OHRP). Medical research is overseen by the Food and Drug Administration (FDA). The two sets of regulation share much in common, but the FDA rule has more specific guidance for clinical trials, medical devices, and drugs.

Although the common rule technically applies to federally funded research, in practice the rule applies to virtually all research conducted in the United States or by U.S. researchers. Most institutions, research centers, and universities in the United States have agreements known as federal-wide assurances in which they agree to subject all research to the same scrutiny, regardless of funding source. So, in practice, it is usually safe to assume that all research done in the United States or by researchers based in the United States will be subject to the Common Federal Rule. Below, we briefly outline the basic components of these regulations as they apply to social and behavioral research.

## 统计代写|SPSS代写代考|Informed consent

Human research participants must provide informed consent to participate in research. This means both that participants must consent to their participation in research, and

they must do so with adequate information to decide on their participation. This relates to the principle of respect for persons. In general, participants should be informed about the purposes of research, the procedures used in the study, any risks they might encounter, benefits they will receive, the compensation they will receive, information on who is conducting the study, and contact information in case of questions or problems. Informed consent documents cannot contain any language that suggests participants are waiving any rights or liability claims-participants always retain all of their human and legal rights regardless of the study design. In most cases, consent is documented through the use of an informed consent form, typically signed by both the researcher and the participant. However, signing the form is not sufficient for informed consent. Informed consent involves, ideally, dialogue in which the researcher explains the information and the participant is free to ask questions or seek clarification, after which they may give their consent.

In some cases, documenting consent through the use of a signed form is not appropriate, in which case a waiver of documentation might be issued. In situations where the only or primary risk to participants is that their participation might become known (a loss of confidentiality) and the only record linking them to the study is the signed consent form, a waiver of documentation might be appropriate. In that case, participants receive an information about the study letter, which contains all elements of a consent form, but without the participant signature.

One important note for people who do research involving children is that children cannot consent to participate in research. Instead, their parent or legal guardian consents to their participation in the research, and the child assents to participation. This additional layer of protection (in requiring parental consent) is because children are considered as having a diminished capacity for consent. There are some scenarios in which parental consent might also be waived, such as research on typical classroom practices or educational tests that do not present more than minimal risk. Children are not the only group regulations define as having diminished capacity for consent. Prisoners also have special protections in the regulations because of the strong coercive power to which they may be subjected. Research involving prisoners must meet many additional criteria, but the research must be related to the conditions of imprisonment and must be impractical to do without the participation of current prisoners.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|OVERVIEW OF ETHICAL ISSUES IN HUMAN RESEARCH

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|OVERVIEW OF ETHICAL ISSUES IN HUMAN RESEARCH

In this final section, we overview the landscape in the United States for research ethics. Many of these principles are common to other contexts, but the language, specific regulations, and processes will vary. If you are in a context other than the United States, be sure to consult your ethical regulations. Ethics comprises a broad field of philosophy, but this section is much more narrowly defined. Research ethics with human research specifically refers to the norms, traditions, and legal requirements of doing research with human participants. In most locations, these regulations are referred to as Human Subjects Research (HSR) regulations. As a note for writing about research, the convention is to refer to humans as research participants (not subjects). Humans willingly participate in research; they are not subjected to research. Animals are often referred to as subjects, though, and the regulations date from a time where “subjects” was the common term for humans as well.

## 统计代写|SPSS代写代考|Historical considerations

Entire books have been written on the historical context for modern research ethics regulations. Here, we briefly describe a few key events that led to the system of regulation currently in place in the United States. Of course, other nations have a history that overlaps with and diverges from that of the United States, but many of the same events shaped thinking about ethics regulations in many places. One moment often identified as a key historical marker in research ethics is the Nuremberg Trials that followed World War II. While these trials are best known as the trials in which Nazi leaders were convicted of war crimes, the tribunal also took up the question of research. In Nazi Germany and occupied territories, doctors and researchers employed by the government carried out gruesome and inhumane experiments on unwilling subjects, many of whom were also in marginalized groups (such as Jewish people, LGBTQ people, and Romani people). What emerged from the tribunals was a general condemnation of such work but not much in the way of specific research regulations.

In the United States, the key moment in driving the current systems of regulation was the U.S. Public Health Service (PHS) Tuskegee Syphilis Study. In the current U.S. government, the PHS includes agencies like the National Institutes of Health (NIH) and Centers for Disease Control and Prevention (CDC), plus multiple other parts of the Department of Health and Human Services. Beginning in 1932 , the PHS began a study of Black men in Tuskegee, Alabama, who were infected with syphilis (Centers for Disease Control and Prevention, n.d.). At the time, there was no known cure for syphilis and few protective measures. The PHS set out to observe the course of the disease through death in these men. An important note is that all men in the study were infected with syphilis before being enrolled in the study (the PHS did not actively infect men in Tuskegee with syphilis, though the PHS did actively infect men in Nicaragua for decades in studies that only recently became known to the public). Tuskegee was selected as a site for the study because it was very remote, very poor, and, in segregated Alabama, entirely Black. PHS officials believed the site was isolated enough both physically and socially to allow the study to go on without being discovered or interrupted. Shortly after the study began, penicillin became available as a treatment, and it was extremely effective in treating syphilis. By 1943, it was widely available. However, the men enrolled in the Tuskegee study were neither informed of the existence of penicillin nor treated with the antibiotic. The PHS Tuskegee Syphilis Study continued for 40 years, finally ending in 1972 after a whistleblower brought the study to light. The study had long-term ramifications for medical mistrust among Black populations in the United States, especially in the South (Hagen, 2005). Those continued effects of the study are associated with lower treatment seeking and treatment adherence among Black patients in Alabama, for example (Kennedy, Mathis, \& Woods, 2007). In 1979, the Belmont Report was issued, leading directly to the current system of ethical regulations in place in the United States, and we will see clearly how that study is directly tied to the elements of the Belmont Report.

## 统计代写|SPSS代写代考|The Belmont Reports

The Belmont Report was issued by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research in 1979 (U.S. Department of Health and Human Services, n.d.). The commission was created by the U.S. Congress in 1974 in large part as a response to the PHS Tuskegee Syphilis Study. It outlined the broad principles for conducting ethical research with human subjects. Its principles formed the core of the research regulations in the United States and included: Respect for Persons, Beneficence, and Justice.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Critical approaches

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Critical approaches

Critical approaches are diverse and varied, so this term creates a broad umbrella. However, in general, these approaches hold that reality and truth are subjective (as does interpretivism) and that prevailing notions of reality and truth are constructed on the basis of power. Critical approaches tend to emphasize the importance of power, and that knowledge (and knowledge generation and validation systems) often serve to reinforce existing power relations. A range of approaches might fall into this umbrella, such as critical theory, feminist research, queer studies, critical race theory, and (dis)ability studies. Importantly, each of those perspectives also has substantial variability, with some work in those perspectives falling more into deconstructivism. Because in reality, there is wide variability in how people go about doing research, the lines between these rough categories are often blurred.

What can we know? We can know what realities have been constructed, and we can critically examine how they were constructed and what interests they serve. How do we generate and validate knowledge? Through tracing the ways that power and domination have shaped social realities. There is often an emphasis on locating and interrogating contradictions or ruptures in social realities that might provide insight into their role in power relations. There is also often an emphasis on advocacy, activism, and interrupting oppressive dynamics. What is the purpose of research? To create change in social realities and interrupt the dynamics of power and oppression.

## 统计代写|SPSS代写代考|Deconstructivism

Deconstructivism is another large umbrella term with a lot of diverse perspectives under it. These might be variously referred to as postmodernism, poststructuralism, deconstructivism, and many other perspectives. These perspectives generally hold that reality is unknowable, and that claims to such knowledge are self-destructive. Although truths might exist (or at least, truth claims exist), they are social constructions that consist of signs (not material realities) and are self-contradictory. Work in this perspective might question notions of reality and knowledge or might critique (or deconstruct) the ways that knowledges and truth claims have been assembled. There is some overlap with critical perspectives in that many deconstructivist perspectives also hold that the assemblages of signs and symbols that construe a social reality are shaped by power and domination.
What can we know? We cannot know in this perspective because there is a questioning of the existence of truth. We can, however, interrogate and deconstruct truth claims, their origins, and their investment with power. How do we generate and validate knowledge? In deconstructivist perspectives, researchers often critique or deconstruct existing knowledge claims rather than generating knowledge claims. This is because of the view that truth/knowledge claims are inherently contradictory and self-defeating. What is the purpose of research? To critique the world, knowledge, and knowability. One of the purposes of deconstructivist research is to challenge those notions, pushing others to rethink the systems of knowledge that they have accumulated.

## 统计代写|SPSS代写代考|Connecting epistemologies to perspectives and methods

In briefly reviewing major epistemological frames, we want to emphasize that epistemologies often do not fit neatly into these categories, nor are there only four kinds of epistemologies. These paradigms are quite expansive, and many researchers identify somewhere between these categories or with parts of more than one. In other words, the neatness with which we present these frames in this text is deceiving in that the reality of research and researchers is much messier, richer, and more diverse. One distinction that is common between qualitative and quantitative work is the openness with which researchers discuss their epistemological positions. Many qualitative researchers describe in some depth their epistemological and ideological positions in their published work. By contrast, the inclusion of that discussion is quite rare in published quantitative work. However, the ideological and epistemological stakes very much matter to the kinds of research a researcher does and the kinds of questions they ask.

One way that this happens is in the selection and mobilization of a theoretical perspective. As we described earlier in this chapter, good research questions are theoretically driven. Those theories have ideological and epistemological stakes. In other words, the selection of a theory or theoretical model for research is not a neutral or detached decision. Theories and their use emerge from particular epistemological stances and attempts to engage theories apart from their epistemological foundations are often frustrated. A key issue for this text, which focuses on quantitative analysis, is that most quantitative methods come from positivist and post-positivist epistemologies. One reason quantitative manuscripts often do not discuss epistemology is that there is a strong assumption of post-positivism in quantitative work. In fact, as we will discover in later chapters, the statistical models we have available are embedded with assumptions of positivism. That is not to say that all quantitative work must proceed from a post-positivist epistemology. However, being mindful of the foundations of quantitative methods in post-positivism, researchers who wish to engage these methods from other epistemological foundations will need to work with and in the tension that creates.

There is often some natural alignment between epistemology, theoretical perspective, and research method. Each method was created in response to a specific set of theoretical and epistemological beliefs. As a result, some methods more easily fit with certain theoretical perspectives which more easily fit with a particular epistemology. We have hinted at the fact that quantitative methods were designed for post-positivist work and thus fit more easily with that epistemology. There is also an array of theoretical perspectives that emerge from post-positivist work that are thus more easily integrated in quantitative work. But to reiterate it is possible to do interpretivist or critical work using quantitative methods. In future chapters, we will highlight some case studies that do so. Any such work requires careful reflection and thought, especially about the assumptions of quantitative work, and must be done carefully. Regardless of your position, we strongly urge students and researchers to consider their own epistemological beliefs and how they influence and shape the directions of their research.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Reading published research and finding gaps

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Reading published research and finding gaps

As you read more and more recently published research, you will begin to notice what’s missing. Sometimes it will be a specific idea, variable, or concept that starts to feel stuck in your head but isn’t present in the published research. Other times, you will have some idea you hope to find what the research has to say about but will be unable to find much on the topic. Of course, sometimes what we think is missing in the literature is really just stated in another way. So, it is important to search for synonyms, different phrasings, and alternative names for things. However, over time, as you read, you will start to notice the areas that have not yet been addressed in the published research. Those gaps could be a population that has not been adequately studied, a component of theoretical models that seems to be missing, a variable researcher have not adequately included in prior work, or a reframing of the existing questions. Those gaps are often a great way to identify research problems and questions for future research. Finding gaps is not the only way to identify necessary new research, but it is a common method for doing so.

One key point in reading the published research is that authors write from a variety of different perspectives. Some are engaging different theoretical models that seek toexplain the same problem using different tools. Other times, the differences reflect qualitative, quantitative, and mixed-method differences in how research is conceptualized and presented. The differences also might relate to theories of knowledge or epistemologies. Those epistemologies shape vastly different ways of writing and different ways of presenting data and findings or results. In the next section, we briefly describe the methodological approaches that are common in educational research: qualitative and quantitative methods. We then turn to questions of epistemology.

## 统计代写|SPSS代写代考|TYPES OF RESEARCH METHODS

There are two main approaches to educational research: qualitative and quantitative. Importantly, the distinctions between these are not as cut and dried as they might appear in our description of them. While we provide some ways of distinguishing between these kinds of research, they do not exist in opposition to one another. Many researchers make use of elements of qualitative and quantitative methods (multimethod research) and others blend qualitative and quantitative approaches and analyses (mixed-method research). In practice, the lines between methods can become blurry, but the purpose of this section is to provide some basic sense that there are different kinds of approaches that answer different kinds of questions with different sorts of data. In general, quantitative research deals with numbers and things that can be quantified (turned into numbers). This textbook focuses on quantitative research. Qualitative research deals with things that are not numbers or that cannot be quantified (like textual or interview data), though some qualitative research also includes numbers, especially frequencies or counts. These two kinds of research also ask different kinds of questions. We will briefly explain both using the questions: What kinds of questions can be asked? What kinds of data can be analyzed? How are the data analyzed? What kinds of inferences are possible?

• What kinds of questions can be asked? In quantitative research, questions typically center around group differences, changes in scores over time, or the relationship among variables. Usually, these questions are focused on explaining or predicting some kind of quantifiable outcome. How are test scores different between groups getting treatment A versus treatment B? How does attention change across three kinds of tasks? What is the relationship between attention and test score? These questions are all quantitative sorts of questions, and all involve specifying a hypothesis beforehand and testing if that hypothesis was correct. Qualitative research answers very different kinds of questions. They usually do not involve pre-formulated hypotheses that are subjected to some kind of verification test. Instead, qualitative research usually seeks deep description and understanding of some idea, concept, discourse, phenomenon, or situation. How do students think about the purpose of testing? How do teachers think about attention in planning lessons? Qualitative work will normally not test group differences or evaluate the association between variables but will instead seek to provide a deeper understanding of a specific moment, situation, concept, person, or idea.

## 统计代写|SPSS代写代考|Epistemology and the nature of knowledge

One way in which various research approaches differ is in their epistemology. While many quantitative methods courses and books avoid this topic entirely, knowing about the major epistemological perspectives can help clarify how research approaches differ. Epistemology refers to an individual’s beliefs about truth and knowledge. For our purposes, we focus on some key questions: What can we know? How do we generate and validate knowledge? What is the purpose of research? We will briefly overview several major perspectives. We do want to be clear that our brief treatment in this section cannot adequately capture the nuance, diversity, or depth of any of these perspectives, but we intend to highlight the basics of each.

## 统计代写|SPSS代写代考|TYPES OF RESEARCH METHODS

• 可以问什么样的问题？在定量研究中，问题通常围绕群体差异、分数随时间的变化或变量之间的关系。通常，这些问题的重点是解释或预测某种可量化的结果。接受治疗 A 组和接受治疗 B 组之间的测试分数有何不同？注意力如何在三种任务中发生变化？注意力和考试成绩有什么关系？这些问题都是定量问题，都涉及事先指定一个假设并测试该假设是否正确。定性研究回答了非常不同类型的问题。它们通常不涉及经过某种验证测试的预先制定的假设。反而，定性研究通常寻求对某些想法、概念、话语、现象或情况的深入描述和理解。学生如何看待考试的目的？教师如何看待计划课程中的注意力？定性工作通常不会测试群体差异或评估变量之间的关联，而是寻求对特定时刻、情况、概念、人物或想法提供更深入的理解。

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

## 统计代写|SPSS代写代考|Basic issues in quantitative educational research

SPSS主要用于数据管理、高级分析、多变量分析、商业智能。

statistics-lab™ 为您的留学生涯保驾护航 在代写SPSS方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写SPSS方面经验极为丰富，各种代写SPSS相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• Advanced Probability Theory 高等楖率论
• Advanced Mathematical Statistics 高等数理统计学
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 统计代写|SPSS代写代考|Finding and defining a research problem

Often, people arrive at a research problem based on their observations or experiences with educational systems. There may be some issue that sticks with an individual that they ultimately pursue as a research problem. They may arrive at that problem because of noticing a certain pattern that keeps repeating in classrooms, or by experiencing something that does/does not work in education, or by reading about current issues in education. They may feel personally invested in a particular problem or simply be bothered by the persistence of a particular issue. Sometimes, students might find a research problem through working with their advisor or major professor. They might also find a problem by working with one or more faculty on research projects and finding some component of that work fascinating. However, individuals end up being drawn toward a particular topic or issue, making that into a research problem and creating related research questions requires some refinement and definition. We will next explore the major features of a good research question.

## 统计代写|SPSS代写代考|Specific and operationally defined

Part of the difference between these two questions is the level of specificity. Narrowing down to testing specific programs creates a better question than an overly broad “what is best” kind of question. Both examples are specific in another way: they specify the kind of achievement gap (reading) and the point in time at which we intend to measure that gap (fifth grade). It is important to be as specific as possible in research questions to make them more answerable and to define the scope of a study. Researchers should specify the outcome being studied in terms of specific content, specific timeframe, and specific population. They should also specify the nature of the program, intervention, or input variable they intend to study-in our case specifying the kinds of programs that might close reading achievement gaps.

Importantly, each of those elements of the research question will need to be operationally defined. How do we plan to define and measure reading achievement? How will we define and measure race? What is our definition of a racialized achievement gap? What are the specific mechanisms involved in the after-school and the summer reading programs? Each of these elements must be carefully defined. That operational definition (operational because it is not necessarily a universal definition, but is how we have defined the idea or term for this particular “operation” or study) shapes the design of the study and makes it more possible for others to understand and potentially reproduce our study and its results.

## 统计代写|SPSS代写代考|Finding published research

Peer-reviewed journal articles are articles published in a journal (typically very discipline and subject-area specific publications) that have undergone peer review. Peer review is a process wherein a manuscript is sent to multiple acknowledged experts in the area for review. Those reviewers, typically between two and four of them, provide written comments on a manuscript that the author(s) have to address before the manuscript can be published as an article. In other cases, the reviewers might recommend rejecting the manuscript altogether (in fact, most journals reject upwards of $80 \%$ of manuscripts they receive).

Often, manuscripts go through multiple rounds of peer review before publication. This is a sort of quality control for published research. When something is published in a peer-reviewed journal, that means it has undergone extensive review by experts in the field who have determined it is fit to be published. Ideally, this helps weed out questionable studies or papers using inadequate methods. It is not a perfect system, and some papers are still published that have major problems with their design or analysis. However, it is an important quality check that helps us feel more confident in what we are reading and, later, citing.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。