final and χ2

December 3, 2009


Sorry about the χ2 test. This presentation and trip took more time than I thought. I’m sharing the answers below for those of you that want to review.

The final exam can be completed in 2 hours. There is a short closed book part, then an open book, open SPSS part. I have crunched a lot of raw data for you, pay attention to the entire problem statement an make a good decision about what you need to do to reach a conclusion. Once you’ve made your decision jump in an knock it out. Don’t mess around or doubt yourself.

answer to test for review:

For each problem below and on the back of this sheet solve using the appropriate chi square test and report a complete conclusion statement in APA style given your work. I am leaving you some space below each problem to write your conclusion. There is no closed book section on this test, but you might have closed book questions on the final exam for chapter 14. Be sure to review that chapter and reflect on your work with Chi Square to be prepared to answer those questions.

–A psychology professor wants to see whether Elementary Statistics (MATH 2400) is a necessary prerequisite for his statistics course. For three semesters, he records the number of students passing, failing, or dropping the course as a function of whether they have had an elementary statistics course in the math department. Determine whether the MATH 2400 and the No MATH 2400 groups differ significantly.

Pass      Fail      Drop

MATH 2400         25      5      5

No MATH 2400         12      14      8

Conclusion: Students are more likely to fail or drop the course if they haven’t had elementary statistics in the Math dept, c2 (2, N = 69) = 9.51, p < .01.


–A professor teaching introductory psychology gave 25 As, 35 Bs, 60 Cs, 30 Ds, and 20 Fs to 170 students in her class. According to the normal curve, she should have given about 4% As, 14% Bs, 64% Cs, 14% Ds, and 4% Fs. Use the chi-square test to determine whether the actual grade assignment significantly departed from a normal distribution.

Conclusion: The grade assignment significantly departed from a normal distribution, Χ2 (4, N = 170) = 103.11, p < .01.


–In a study of the relationship between early childhood trauma and adjustment to school, a school psychologist classified students according to whether they had a history of trauma (e.g., severe illness, death of a parent) and by their adjustment to school. The data are given here. Perform a chi-square test to determine whether trauma affects adjustment.


Poor   Average          Excellent

No Trauma      16   30      50

Trauma      14   6      4

Conclusion: Students with a history of trauma were more likely to adjust poorly to school, : c2 (2, N = 120) = 18.94, p < .01.


–A rhesus monkey was trained to make same–different judgments about pairs of objects. For 50 trials, the animal was shown pictures of objects; it made correct judgments on 43 of the trials. Use the chi-square test to determine whether the animal had generalized its learned response from objects to pictures of objects. **Note: The probability of making a correct response on any trial is .5.

Conclusion: The monkey had generalized its learned response from objects to pictures of objects, c2 (1, N = 50) = 25.92, p < .01.

Kurtis, Did you find your keys. They may be hanging on my bulletin board. I found some this weekend.

M/T (16/17) — SPSS work on laptops for chapter 13, commenting conclusions

W/Tr (18/19) — finish SPSS and input HW problems with raw data available. Comment conclusions, get feedback from me.

Tr/F (19/20) — regression tests

M/T (23/24) — chi square lecture

M/T (30/1) — chi square mini-test.

Finals whenever the AVPAA said in the calender!

Regression Lab: ch 13.

November 16, 2009

Here is our material for the regression lab for chapter 13. Once again we’ll do our see one, replicate one, try one on your own approach. You should share your conclusion statements below as a comment if you want feedback. We’ll talk about them at the end of class.

On Wednesday or Thursday you should bring your completed HW so that we can run it through SPSS and practice more conclusion writing.

no class today. Use your time wisely. Solve some problems and write some conclusions we can look at together!

…this Wednesday and Thursday.

I have a feeling there will be a great deal of separation between those that have been attending class and working toward understanding and those that have not this go around. Hope to see everyone today and tomorrow. I want everyone to do well!

Finishing up November:

November 1, 2009

This week we’ll cover the factorial chapter and take our third exam during the lab period.

The week of  the 9th – 13th we’ll cover regression, but we won’t have labs as I have a presentation on Thursday afternoon.

The week of the 16th – 20th we’ll finish regression and take part 1 of test #4 over the regression material. Then on the 23 and 24th we’ll cover chi square. We’ll follow that up with test $4, part 2 over chi square on the 30th and first during our last class periods.

simple ANOVA lab

October 29, 2009

Lab this week will focus on using spss to calculate oneway independent and repeated measures ANOVA. We will also be focusing on post-hoc tests and interpretation. The lab directions, as always, can be found on the content page.

Share your conclusions here as comments. (Then start reading chapter 12).

ANOVA HW conclusions:

October 28, 2009

I would like for everyone to pick one conclusion they feel confident about and one conclusion they do not feel confident about from our HW assignments this week and share them here so that we can all learn and grow together. If you like you my wait until after you exam them in SPSS and work from the output.

Be sure that you label what problem you are working from so that we know what you are talking about ;-)

On Monday and Tuesday I’d like for you to make sure that you complete your HW assignments

and suggested HW problems

  • chapter11: 1,2,3,5,6,7 (only do LSD test by hand as needed for the independent problems)

for chapter 11 (It’s all on the content page). On Wednesday and Thursday, we’ll go over these problems and talk about conclusion statements. In lab on Tr and Fr we will  solve these problems using SPSS and begin talking about Factorial ANOVAs (chapter 12).

I need to go to a meeting on Undergraduate Research tomorrow afternoon. As a result I am having you guys complete these assignments and giving you class time to do that so that we can move ahead more rapidly on Wednesday and Thursday. I hope that you use this time wisely. You are more than welcome to use our classroom space and work together on Monday and Tuesday if you like.