P554 Statistics in Psych, Prof. Kruschke

P554 Statistics in Psychology, Prof. Kruschke
Lab Assignment for Ch. 3 (Part I). Th 11, F 12 Jan 2007.

General instructions. This assignment is to be done in your lab session. Submit your assignment from the lab computer during lab time. If the assignment involves SPSS, be sure that when you open SPSS, you set it so that commands are displayed in the output: Edit -> Options, Viewer tab, check box Display commands in the log.

  • Suppose an experiment has three groups, each with three scores, as follows:
    Group 1: 2.6, 3.6, 4.6
    Group 2: 4.0, 5.0, 6.0
    Group 3: 5.3, 6.3, 7.3
    In SPSS, do a Oneway ANOVA on the data. Can the null hypothesis of no differences between groups be rejected at the .05 level of significance?

  • Now suppose that your null hypothesis is that the scores come from uniform population distributions that range from 0 to 10 (not normal population distributions). Can the null hypothesis of no differences between groups be rejected at the .05 level of significance? To answer this question, adapt the linked SPSS syntax file. (Hint: Find out about the rv.uniform function.) Use your adapted file to generate a sampling distribution of F(2,6) from uniform populations.

    What to turn in and how to turn it in. Your SPSS output viewer will probably contain a mess of trial runs, revisions, and finally correct runs.
    * Clear out all the trial runs, so that you have only the clean final output of your answers to the two bulleted questions above. Be sure the output includes the syntax (called the Log in the output viewer) along with the tables and graphs.
    * The very first thing in your output should be the syntax (Log) of the Oneway ANOVA. Double-click this log and type in (1) your name and student ID number on the first line, and (2) your brief answer to the first question, and (3) your brief answer to the second question. You should click on the lower edge of the text box to enlarge the box so your answer will all be displayed.
    * Save a copy of the output file for your own records, and upload a copy to the Assignments in Oncourse. Go to Oncourse and click on the Assignments link.