Category: Statistics Homework Help

Short Answer Assignment #4

Part 1

PURPOSE: This assignment aims to help you better understand graphical depictions of factorial designs, including main and interaction effects.

TASK: Read the following information and prompts, and use your textbook and class notes to answer the following questions.

CRITERIA: You will be successful on this assignment if you can: (a) Provide a correct answer to all of the questions using course concepts and descriptions that are clear to another reader.

INFORMATION:

Scientists test whether the Independent Variable influences the dependent variable.

Scientists test whether the Dependent Variable depends on the independent variable.

When an experiment has TWO independent variables, the results are broken down:

• Main effect of independent variable #1 on the dependent variable
• Main effect of independent variable #2 on the dependent variable
• Interaction effect of the independent variables on the dependent variable
• The results are often summarized graphically when experiments test the effects of two independent variables on a dependent variable. In this homework assignment, you will be asked to interpret graphical results of experiments with two independent variables.

Quick guide for getting correct answers on this assignment:

• x-axis = the independent variable
• y-axis = dependent variable #1 (“IV #1”)
• Key (upper-right) = independent variable #2 (“IV #2”)
• Is there a main effect of IV #1?
  • If the average slope of the two lines…
    • … is Flat à no main effect of IV #1
      • e.g., both are flat, or if they cancel each other out by making an “X”
    • … both slope upward or downward = main effect of IV #1
• Is there a main effect of IV #2?
  • If the midpoint of the two lines is equal height à no main effect of IV #2
  • If the midpoint of one of the lines is higher/lower than the other à there is a main effect of IV #2
• Is there an interaction effect?
  • If the lines are parallel, there is NO interaction effect.
  • If the lines are NOT parallel, there is an interaction effect.
• Note: The graphs below represent fabricated data. It’s all made up, just for interpretation practice.

ASSIGNMENT:

For each graph, answer the questions. Explain all effects.

Example:

1. Graph 1
   1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 2

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 3

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 4

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 5

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 6

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 7

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

• Graph 8

1. Dependent Variable:

• Independent Variable 1:

• Independent Variable 2:

• Main effect of IV1:

• Main effect of IV2:

• Interaction Effect:

Part 2

PURPOSE: The purpose of this assignment is to help you practice designing a research study and gain a better understanding of small-N research designs.

TASK: Read the prompts below and answer the following questions that will help you design a series of small-N studies.

CRITERIA: You will be successful on this assignment if you can: (a) Provide a correct answer to all of the questions using course concepts and descriptions that are clear to another reader.

ASSIGNMENT:

Read the prompts and answer the questions:

1. Imagine you live in a dormitory with a roommate. This roommate is particularly messy, and you would like to change a behavior of theirs to improve the cleanliness of your shared room.
   1. Pick a behavior you think would improve the cleanliness of your shared dorm.

• What is an intervention you will use to change your roommate’s behavior?

• Use a stable-baseline design to test your intervention and sketch a graph to show what it would look like if the intervention worked.

• A teacher wants to show that attending after school tutoring improves students quiz grades over the course of a semester.
  • Design a multiple-baseline study to support her view.

• Sketch a graph or graphs to show what it would look like if the teacher was right.

• A researcher thinks that starting your day by journaling improves your daily mood.
  • Design a reversal study to test the researchers’ hypothesis.

• Sketch a graph to show what it would look like if the researcher was correct.

Part 3

PURPOSE: The purpose of this assignment is to help you practice your research skills while building your understanding pf Psychology’s Replication Crisis.

TASK: Using the UTA library or Google Scholar, find the journal article below. Once you have read the article and have a good understanding of the study, answer the following questions.

CRITERIA: You will be successful on this assignment if you can: (a) Provide a correct answer to all of the questions using course concepts and descriptions that are clear to another reader, (b) demonstrate you have read the article by citing specific facts and information from the article.

ASSIGNMENT:

Using the UTA library or Google Scholar, find the article titled “Psychology, Science, and Knowledge Construction: Broadening Perspectives from the Replication Crisis” and read the first 7 pages up through the sub-heading “Statistical Responses…” Then, answer the questions below.

1. How would you summarize psychology’s replication crisis? What is it?

• According to Shrout and Rodgers (2018), what are the major factors that have contributed to the crisis?

• What steps have been taken to address the crisis? Knowing what we know now, how can researchers be proactive about NOT making the crisis worse?

• Can you think of any other steps that can be taken to address the crisis?

• What other thoughts do you have about this issue?

Complete a data analysis report using ANOVA for assigned variables.

Introduction

You’re starting to learn some important information about your data, but you still want to know more. It’s time for a one-way analysis of variance (ANOVA). Unlike t-tests, which only allow for comparisons of two groups, ANOVA will allow you to examine potential group differences for variables with multiple levels.

Instructions

For this assessment:

• Use the Data Analysis and Application template (DAA Template [DOCX]).
• For help with the statistical software, refer to the JASP Step-by-Step: ANOVA [PDF] document.
• View JASP Speedrun: ANOVA [Video] for a brief tutorial video on this assessment.
• Refer to the 7864 Course Study Guide [PDF] for information on analyses and interpretation.
• For information on the data set, refer to the 7864 Data Set Instructions [PDF] document.

The grades.jasp file is a sample data set. The data represent a teacher’s recording of student demographics and performance on quizzes and a final exam across three sections of the course. 

This assessment is on ANOVA. You will analyze the following variables in the grades.jasp data set:

Variables and Definitions

Step 1: Write Section 1 of the DAA: Data Analysis Plan

• Name the variables used in this analysis and whether they are categorical or continuous.
• State a research question, null hypothesis, and alternate hypothesis for the ANOVA.

Step 2: Write Section 2 of the DAA: Testing Assumptions

Test for one of the assumptions of ANOVA – homogeneity.

• Create statistical software output showing the Levene’s Test for Equality of Variances.
• Paste the table in the DAA template.
• Interpret the homogeneity test to determine whether the assumption of homogeneity is violated or is not violated.

Step 3: Write Section 3 of the DAA: Results & Interpretation

• If the homogeneity assumption is not violated (Section 2), run the “Homogeneity corrections: None” version of the ANOVA. Follow up with the “Standard” version of the Tukey post hoc test.
• However, if the homogeneity assumption is violated (Section 2), run the “Homogeneity corrections: Welch” version of the ANOVA. Follow up with the “Games-Howell” version of the Tukey post hoc test.

Paste the following statistical software tables into the document:

• Descriptives table.
• ANOVA table.
• Post Hoc Tests table (Tukey correction).

Below the output:

• Report the means and standard deviations of quiz3 for each group of the section variable.
• Report the results of the F test and interpret the statistical results against the null hypothesis; state whether the null hypothesis is rejected or not rejected. 
• Finally, if the F is significant, interpret the post-hoc tests.

Step 4: Write Section 4 of the DAA: Statistical Conclusions

• Provide a brief summary of your analysis and the conclusions drawn about this ANOVA.
• Analyze the limitations of the statistical test and/or possible alternative explanations for your results.

Step 5: Write Section 5 of the DAA: Application

• Name an independent variable (the IV should have three or more groups or categories) and dependent variable that would work for such an analysis and why studying it may be important to the field or practice.

Submit your DAA Template as an attached Word document in the assessment area.

Software

The following statistical analysis software is required to complete your assessments in this course:

• Jeffreys’s Amazing Statistics Program (JASP).

Refer to the Tools and Software: JASP page on Campus for general information. Make sure that your statistical software is downloaded, installed, and running properly on your computer.

Competencies Measured

By successfully completing this assessment, you will demonstrate your proficiency in the course competencies through the following assessment scoring guide criteria:

• Competency 1: Analyze the computation, application, strengths, and limitations of various statistical tests.
• Analyze statistical assumptions.
• Competency 2: Analyze the decision making process of data analysis.
• Articulate the data analysis plan.
• Competency 3: Apply knowledge of hypothesis testing.
• Interpret statistical results and hypotheses.
• Competency 4: Interpret the results of statistical analyses.
• Explain statistical conclusions, the limitations of the test, and/or possible alternative explanations.
• Competency 6: Apply the results of statistical analyses (your own or others) to your field of interest or career.
• Analyze the potential applications of the test in the field and their implications.
• Competency 7: Communicate in a manner that is scholarly, professional, and consistent with the expectations for members in the identified field of study.
• Communicate in a manner that is scholarly and professional, and adheres to APA style and formatting.

The requirement for this lesson’s assignment is to conduct PCA. This PCA will tell you whether or not an EFA is needed to explore latent factors within your items.

Use the following scenario as a reference when completing this week’s assignment.

What is the main purpose of a Principal Component Analysis?

Scenario: The University of Sussex constantly seeks to employ the best people as lecturers. The University wanted to revise the Teaching of Statistics for Scientific Experiments (TOSSE) questionnaire, which is based on Bland’s (1977) theory that says that good research methods lecturers should have:

● A profound love of statistics ● An enthusiasm for experimental design ● A love of teaching ● A complete absence of normal interpersonal skills.

These characteristics should be related (i.e., correlated). The University of Sussex revised this questionnaire to become the “Teaching of Statistics for Scientific Experiments – Revised” (TOSSE–R), as shown in Figure 3. NCU further modified this humorous tool for use in this week.

Figure 3

TOSSE-R Questionnaire (modified from Bland, 1977)

They gave this questionnaire to 239 research methods lecturers around the world to determine if it supported Bland’s (1977) theory. The data are in TOSSE-R.sav file. Address the following questions:

1. Based on the readings and this week’s lesson, what is the main purpose of factor analysis? What is the main purpose of a Principal Component Analysis?

2. What is the difference between PCA, EFA, and CFA?

3. According to the readings, what is the appropriate value for a factor loading?

4. Conduct a PCA and interpret the factor structure.

5. Present the results of the PCA, including a discussion of whether you think an EFA would be needed based on the results of the PCA and why.

6. How many factors were extracted from the questionnaire?

Length: Complete responses to all six questions and prompts. Please include the question prompts along with your responses in your assignment submission. In addition to a WORD (.doc) file with the answers to the assignment questions, also include the output (.spv) file.

NOTE: SPSS automatically generates the .spv file as you work in SPSS. When you close your SPSS main window, SPSS will ask you if you want to save the output file. Click ‘yes’, then save to your computer and upload with your assignment.

NOTE: In SPSS, you must be careful when running an EFA because the default is set to PCA; in the menu “Analyze” “Dimension reduction” “Factor” and then in the box labeled “Factor Analysis: Extraction” you will see “Method” and the default is already set to “principal component.” Principal component is the PCA, so if you leave this, you will be conducting a PCA.

References: No references are required, though any sources used other than those provided within the assignment should be cited and referenced in APA format