SPSS Homework 2

W A L D E N U N I V E R S I T Y

P U B H 6 0 3 3 / 8 0 3 3

I N T E R P R E T A T I O N & A P P O F D A T A

Getting Started on the Final Project

Review Instructions

 Before starting the first assignment associated with the Final Project (Week 4), check the three areas of the course that contain instructions and read through each of them carefully:

1. Course Information: Final Project rubrics and dataset

2. Week 4 Project tab

3. Week 11 Final Project tab

Download and Open the Final Project Dataset

 Locate the “FinalProject.sav” datafile in the Course Information or Week 4 Project section of the classroom.

 Click on the link and save the file to your computer’s hard drive.

 To open the file, you must first open SPSS.  Click the Start menu

 Click on IBM SPSS Statistics 21 (or whatever version you have)

 Under the “Open an existing data source” box, double-click “More Files”

 Locate the FinalProject.sav file, highlight it, and click Open

Run a Data Dictionary

 The Data Dictionary produces information on all of the variables, including names, labels, and level of measurement (nominal/categorical, ordinal, and scale/quantitative).

 Click on File > Display Data File Information > Working File

 Information will be displayed in the Output Viewer window.

 Remember to include the Data Dictionary in your Week 4 Final Project Assignment.  Right click the table, click “Copy”, and paste the table to Word

Select A Disease of Interest

 Using information from the Data Dictionary, select one of the five diseases as the dependent variable for your Final Project  Dengue infection  HIV infection  CHD mortality  Diabetes status  Lung cancer stage

Select Independent Variable(s)

 Use the Data Dictionary to identify independent variables that relate to your selected disease (dependent variable)

 Independent variables include:  Demographics: Gender, Age, Race/Ethnicity, Income, Education,

Insurance, Urban, Region  Clinical Risk Factors: BMI, Cholesterol  Behavioral Risk Factors: Alcohol, Tobacco, IDU, Condom, Exercise,

Fruit/Vegetable

 Now select 1-2 independent variables to include in your study  Your decision should be based on the literature, clinical significance,

or interest in the topic  Be sure that the connection between your independent variables and

disease (dependent variable) is plausible

Develop a Research Question

 Your Final Project will be guided by the research question you develop.

 What makes a good research question?  A definable relationship between at least one independent

variable and a dependent variable.  An issue that fills a gap in the literature (if possible for this

course, a must for a dissertation).

 The research question should clearly express that you will examine the association between 1-2 independent variables and your disease of interest (dependent variable).

Research Question Examples

 Is there an association between sun exposure and skin cancer?

 Is there a difference in asthma prevalence between males and females in the United States?

 Does ecstasy use vary by age in the United States?

 Do geographic location and income predict malaria infection?

 It is recommended that you choose a simple research question for the Final Project. In Week 9, you will be asked to perform statistical analysis using SPSS to answer the research question.

List the Null and Alternative Hypotheses

 After developing your research question, then you must list the null and alternative hypotheses.

 Null = no association or difference

 Alternative = there is an association or difference

 Example:

 Is there an association between sun exposure and skin cancer?

 Null = There is no association between sun exposure and skin cancer.

 Alternative = There is an association between sun exposure and skin cancer.

Levels of Measurement

 Go back to the Data Dictionary and determine the level of measurement for each of the variables in your research question.

 Levels of measurement help you determine the appropriate statistical test to answer your research question.

 Examples:  Malaria infection = nominal/categorical (Yes/No)

 Geographic location = nominal/categorical

 Income = ordinal

 BMI = scale/quantitative

Select the Appropriate Statistical Test

 In Week 7, you are asked to identify the appropriate statistical test to answer your research question.

 The answer depends on the number of variables and levels of measurement. See the next slide for a table that will help you make an appropriate decision.

 These are the most commonly used statistical tests that are covered in this course:  Chi-square

 Pearson correlation

 T-test

 ANOVA

 Logistic regression

 Linear regression

What statistical test should I use? Nature of

Independent

Variables

Nature of Dependent

Variable Test(s)

1 IV with 2 levels

(independent groups)

quantitative Independent sample t-test

ordinal Wilcoxon-Mann Whitney test

categorical Chi- square test

Fisher's exact test

1 IV with 2 or more levels

(independent groups)

quantitative one-way ANOVA

ordinal Kruskal Wallis

categorical Chi- square test

1 IV with 2 levels

(dependent/matched groups)

quantitative paired t-test

ordinal Wilcoxon signed ranks test

categorical McNemar

1 IV with 2 or more levels

(dependent/matched groups)

quantitative one-way repeated measures

ANOVA

ordinal Friedman test

categorical repeated measures logistic

regression

2 or more IVs

(independent groups)

quantitative factorial ANOVA

ordinal ordered logistic regression

categorical factorial

logistic regression

1 quantitative IV

quantitative correlation

simple linear regression

ordinal non-parametric correlation

categorical simple logistic regression

1 or more quantitative IVs

and/or

1 or more categorical IVs

quantitative multiple regression

analysis of covariance

categorical multiple logistic regression

discriminant analysis

Examples

 Is there an association between sun exposure and skin cancer?

 Sun exposure (IV) = nominal/categorical

 Skin cancer (DV) = nominal/categorical

 Correct test = Chi-square

 Is there a difference in asthma prevalence between males and females in the United States?

 Gender (IV) = nominal/categorical

 Asthma (DV) = scale/quantitative

 Correct test = T-test

Work with Instructor and GA

 Contact your instructor or GA to ensure that your research question will work well for all assignments in the course.

 Be sure to review feedback on each assignment, as they all build into one final paper.  Week 4 = Topic, problem statement, annotated bibliography

 Week 6 = Literature review, hypothesis, and significance

 Week 7 = Methods

 Week 9 = Results, codebook, syntax

 Week 11 = Final Paper, synthesize all sections and add interpretation