were these two different sections at the same class time? that is ... 10AM on mwf? if not ... then there can be all kinds of reasons why means would be this different ... nonewithstanding one or two real deviant scores in either section ...
could also be different quality in the instruction ... all kinds of things of course, if you opted for 95 or 99% cis, the non overlap would be greater ... what is the purpose of doing this in the first place? do not the mean differences really suggest that there is SOMEthing different about the two groups ... ? or ... at least something different in the overall operation of the course in these two sections? At 02:33 PM 10/1/01 -0300, Gus Gassmann wrote: >Stan Brown wrote: > > > Another instructor and I gave the same exam to our sections of a > > course. Here's a summary of the results: > > > > Section A: n=20, mean=56.1, median=52.5, standard dev=20.1 > > Section B: n=23 mean=73.0, median=70.0, standard dev=21.6 > > > > Now, they certainly _look_ different. (If it's of any valid I can > > post the 20+23 raw data.) If I treat them as samples of two > > populations -- which I'm not at all sure is valid -- I can compute > > 90% confidence intervals as follows: > > > > Class A: 48.3 < mu < 63.8 > > Class B: 65.4 < mu < 80.9 ============================================================== dennis roberts, penn state university educational psychology, 8148632401 http://roberts.ed.psu.edu/users/droberts/drober~1.htm ================================================================= Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =================================================================
