Christopher Larsen said on 10/6/02 7:08 PM: >Thank you very much for you reply. I wish to compare the means of my data >with the norms established by the test. The particular memory test I am >using is the Wechsler Memory Scale-III which was co-normed with the WAIS- >III. Each scale of the WMS-III (General Memory, Recognition Memory Visual >Memory) has a mean of 100 and a SD of 15. I would like to compare the >results from my data set (actually means from each scale) against those >norms. I had assumed that a One-Sample T would be appropriate. To do a Z >I was thinking I need the N of the normative sample (A huge stratified >sample based on US census data). However my N is 50 and differences in N >would be huge. Uncomfortable with that I felt that a one sample T sould >be more appropriate since the normative data set against which it is >being compared is so large and appears to represent the general >population so well. As I look at the results printing out on SPSS, I am >seeing seeing significant differences but am also wondering if there is a >flaw in my statistical logic.
The N in a Z test is the n of the sample, not of the norming sample. With that said, it seems to me that you likely your sample does not have a SD of 15. First just do a descriptive run to see what the SD of your sample is. Paul . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
