Your Name __________________________________ Psychology 201W, Spring 2002 Dr. John A. Johnson

Lab assignment #7 -- Practice computing statistics (Due in lab Friday, March 15)

This lab is worth 30 points.

The purpose of this assignment is to provide some practice in calculating basic statistics and to learn about sharing data electronically. You are to use the spreadsheet function of Excel to read a file containing the survey data we collected as a class. By using the calculating functions of the spreadsheet, you will compute:

1. the means for two variables in the study

2. deviation scores for the two variables

3. squared deviation scores for the two variables

4. sums of squares, sample and population variances, and sample and population standard deviations for the two variables (remember, sample variance is calculated by dividing the SS by (N-1); the population variance is calculated by dividing by N).

5. z-scores based on the population standard deviation for the two variables

6. a column containing the products of the two sets of z-scores

7. the correlation between the two variables, which is the mean of the products of the z-scores

To isolate and keep track of the two variables you will be correlating, you will need to add and move some columns in the spreadsheet. If you miss the in-class demonstration of how to do this on March 1st, you'll have to get help after spring break.

To turn in your assignment, send your spreadsheet file to me as email attachment. To do this, begin to compose a note, addressing it to me at the following address:

In your note, indicate the two variables you have chosen to correlate and why you have chosen them. Then make sure you include your spreadsheet file as an attachment before you send it to me. This is done by opening the Message menu at the top of your screen and highlighting the Attach document item. A dialog box will come up, asking for the name of your spreadsheet file. Tell it the name of your file and then continue to send your note to me.

You can choose from our data set any two variables you predict will be correlated (either positively or negatively),

or;

you can choose two variables whose relationship you cannot predict (you are not sure whether they are correlated or not) but whose relationship you are curious enough about to compute a correlation.

Either way, choose a pair of variables about which you will be able to do a short write-up for Paper 2. This paper will be written in APA format, so it will include a Title, Abstract, Introduction (where you explain why you are determining the relationship between the two variables), Methods, Results, and Discussion. You will have a References section only if you cite someone’s work.

The variables in our data file are organized as follows:

 A Code number for interviewer [1-8] B Participant number [1-66] C My parents or guardians played a major role in my decision to attend college. [1-5; strongly disagree – strongly agree] D One reason I decided to attend college was to better fit in or conform to society. [1-5; strongly disagree – strongly agree] E I decided to attend college because I was not ready to join the workforce. [1-5; strongly disagree – strongly agree] F I decided to attend college because I thought this would help be obtain a better, higher-paying job. [1-5; strongly disagree – strongly agree] G I work just as hard as I can, to my full ability, in my classes. [1-5; strongly disagree – strongly agree] H Given my ability, my grades are as high as they possibly could be. [1-5; strongly disagree – strongly agree] I President Spanier has said that tuition may increase by 12-14% next year. If this increase occurs, I would have to reconsider whether to continue my studies at Penn State. [1-5; strongly disagree – strongly agree] J If tuition increases by 12-14% next year, I would seriously consider attending another school. [1-5; strongly disagree – strongly agree] K If answer to above question is somewhat or strongly agree, to which school would you most likely transfer? [1=IUP; 2-Clarion; 3=Gannon; 4=Pitt; 5=undecided] L If tuition increases by 12-14%, I would expect to see a significant increase in student programs, majors, and services. [1-5; strongly disagree – strongly agree] M Loans (must be paid back)? (0-100%) N Scholarships (for achievement)? (0-100%) O Financial aid (based on need; doesn't have to be repaid)? (0-100%) P Money I've earned? (0-100%) Q Money from my family (doesn't have to be repaid)? (0-100%) R What year did you graduate from high school?  [1982-2001] S Sex [male = 1, female = 2)]

I have placed these letters, A-S, in the first row of the spreadsheet and the items themselves in the second row. This way, if you move columns around or add columns to your spreadsheet, you will be able to keep track of where the variables are.