Bruce Weaver wrote: > Paige Miller wrote: > >> Archana wrote: >>> Iam textile engineering looking for some statistical advice. >>> I have the following test garments (total 4 types)- >>> >>> Type A - medium and large >>> Type B - medium and large >>> >>> The same 8 subjects wore the shirts and perfomred some physical >>> activity. Their heart rate, skin and core temperature etc were >>> monitored. I want to find out if the heart rate or the other >>> parameters are significant for the 4 types of shirt. What do i follow? >>> One way anova or repeated measures design and why? >> >> Neither, I think. >> >> This is not a one-way ANOVA, as you have three factors (Type A, Type B >> and subject). Therefore, it should be a three-way ANOVA. I see nothing >> that would indicate this is a repeated measures design, which to me >> usually implies repeat measurements over time. Subjects are not a >> repeated measure, they are a classification variable that is crossed >> with Type A and Type B.
> As I understand the original post, the sources of variance in the > summary table are as follows: > > Source df > ----------- -- > Between Ss 7 > Within Ss > A 1 > A*S 7 (error term for A) > B 1 > B*S 7 (error term for B) > A*B 1 > A*B*S 7 (error term for A*B) > --------- -- > Total 31 > I would call this a 2x2 repeated measures (or within-Ss) design, with > repeated measures on both A and B. I gather that you would call it > something else, Paige. Is that right? I think it all boils down to terminology differences, as I can't argue with your ANOVA table. I think of this as a full factorial in A and B, with a blocking variable named "subject". As I said in my first post on this topic, I think of repeated measures as you apply a "treatment" to an experimental unit, and then record that experimental unit's value over time. For example, you give a drug to a subject, then record a measurement of that subject at 1 day, 2 days, 3 days, ... Perhaps that's an extremely narrow view of what "repeated measures" is, but that's how I use the term. -- Paige Miller Eastman Kodak Company paige dot miller at kodak dot com http://www.kodak.com "It's nothing until I call it!" -- Bill Klem, NL Umpire "When you get the choice to sit it out or dance, I hope you dance" -- Lee Ann Womack . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
