m v wrote: > > My wife and I both have degrees in math and have taken undergrad > statistics courses long ago but are having trouble helping our child > determine the appropriate statistics to use for her middle school > science project and how to translate the result into english for her > conclusion. > > Her project was to find if short term memory was better for young > adults than for younger or older age groups. She devised a memory > test and tested 10 people in each of five different age groups.
I think I'd want to know a little about the precise age groups. As far as STM goes you'd expect young children (say under 7 or 8) to be worse than young adults and you might expect age-related decline to effect very old adults (say 70+; though your daughter might have a biased sample of healthy, active older participants). I think it would be hard to show effects in between because the differences might be quite small. Any differences will reflect strategy differences (especially for very young subjects who don't use efficient memory strategies) as well as STM 'capacity' per se. Also the materials influence the extent of differences - some materials will probably show bigger effects (e.g., nouns, easily nameable pictures) because they make more strategies available. Given the target audience I think that confidence intervals and a plot of means might be appropriate (though not the most powerful test). Plotting 1.4 standard errors will give you approximately an independent t test at p<.05 between means. Thom . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
