Richard Ulrich wrote: > Taking the logs of the durations is an obvious thing. I believe it > does not take special justification because a statistician should have > recommended that before you began.
Yes - its fairly common in this field (as is taking the medians of multiple trials). > As an alternative, re-stating the durations as time-per-word seems to > me to be a realistic version of the outcome, which also might > avoid interactions and heterogeneity of variances. No. The appropriate correction in the field is time/syllable. This tends to produce cleaner results than time per word. There is a slight bias in that the time to read a sentence is: c + aS (S is number of syllables, c is a constant related to processes that don't depend on sentence length). The correction will over-correct short words. An alternative is to include sentence length in syllables (or expected mean sentence length if the stimuli are randomized) as a covariate. This will produce an unbalanced ANOVA that can be analysed in standard packages with a little tweaking: Lorch, R. F., & Myers, J. L. (1990). Regression analyses of repeated measures data in cognitive research. Journal of Experimental Psychology: Learning, Memory and Cognition, 16, 149-157. Thom . . ================================================================ This list will soon be replaced by the new list EDSTAT-L at Penn State. Please subscribe to the new list using the web interface at http://lists.psu.edu/archives/edstat-l.html. ================================================================
