 |
 |
You did nothing wrong. Here is the logic of why they are equal: 1st (A >B) > 2nd (A >B) ===> (A1-B1) - (A2-B2) = 0 Now we can rearrange it... A1-B1-A2+B2=0, which can be expressed as (B2-A2) - (B1-A1) ====> 2nd (B >A) > 1st (B >A) Best Regards, Donald McLaren ================= D.G. McLaren University of Wisconsin - Madison Neuroscience Training Program Office: (608) 520-0586 ===================== This e-mail contains CONFIDENTIAL INFORMATION which may contain PROTECTED HEALTHCARE INFORMATION and may also be LEGALLY PRIVILEGED and which is intended only for the use of the individual or entity named above. If the reader of the e-mail is not the intended recipient or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that you are in possession of confidential and privileged information. Any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this e-mail unintentionally, please immediately notify the sender via telephone at (608) 520-0586 or email. On Fri, Aug 6, 2010 at 11:34 AM, Andrew McReynolds <[log in to unmask]> wrote: > Hello, > > We're having trouble running a paired t-test in SPM5. In our design, we have two conditions, A and B, and for each subject, we generated contrasts for A > B and B > A. We ran these subjects twice and want to compare 1st scan (A > B) > 2nd scan (A > B) and vice versa, so we used a paired t-test. However, > 1st (A >B) > 2nd (A >B) equalled 2nd (B >A) > 1st (B >A), and > 1st (B > A) > 2nd (B > A) equalled 2nd (A > B) > 1st (A > B). > > Do you know what we did wrong? > > Thank you for any help. > > Andrew >