## Assignment: Identifying Statistical Tests

Assignment: Identifying Statistical Tests
Assignment: Identifying Statistical Tests
Identifying Statistical Tests in the Literature Worksheet
PSYCH/625 Version 5
1
University of Phoenix Material
Identifying Statistical Tests in the Literature Worksheet
Research in the University Library to find three empirical (those containing data) research articles using one of the analytic methods studied this week (i.e., z test, independent sample t test, repeated measures t test).
Select articles that are of interest to you and include the citations at the end of this document.
Fill out the following tables and answer each question in 1 to 2 sentences.
Title of Article:
Question
What is the null hypothesis (implied or explicitly stated)?
What is the research hypothesis (implied or explicitly stated)?
What was the type of analysis (z test, independent sample t test, repeated measures t test) chosen, and why was it appropriate?
This page shows how to perform a number of statistical tests using SPSS. Each section gives a brief description of the aim of the statistical test, when it is used, an example showing the SPSS commands and SPSS (often abbreviated) output with a brief interpretation of the output. You can see the page for a table that shows an overview of when each test is appropriate to use. In deciding which test is appropriate to use, it is important to consider the type of variables that you have (i.e., whether your variables are categorical, ordinal or interval and whether they are normally distributed), see for more information on this.
Most of the examples in this page will use a data file called hsb2, high school and beyond. This data file contains 200 observations from a sample of high school students with demographic information about the students, such as their gender (female), socio-economic status (ses) and ethnic background (race). It also contains a number of scores on standardized tests, including tests of reading (read), writing (write), mathematics (math) and social studies (socst). You can get the hsb data file by clicking on .
One sample t-test
A one sample t-test allows us to test whether a sample mean (of a normally distributed interval variable) significantly differs from a hypothesized value. For example, using the , say we wish to test whether the average writing score (write) differs significantly from 50. We can do this as shown below.
t-test
/testval = 50
/variable = write.
The mean of the variable write for this particular sample of students is 52.775, which is statistically significantly different from the test value of 50. We would conclude that this group of students has a significantly higher mean on the writing test than 50.
One sample median test
A one sample median test allows us to test whether a sample median differs significantly from a hypothesized value. We will use the same variable, write, as we did in the example above, but we do not need to assume that it is interval and normally distributed (we only need to assume that write is an ordinal variable).
nptests
/onesample test (write) wilcoxon(testvalue = 50).