Stats-filter: Comparing individual means?
December 6, 2012 8:26 AM Subscribe
StatsFilter: How do I compare the means of an individual at three different points?
posted by Scottie_Bob to science & nature (13 answers total) 1 user marked this as a favorite
Ok, so I'm working on a project just now and I want to find out if the means of my dependent variable X for ONE person at times A, B and C are significantly from one another. I'm not especially interested in finding out if this speaker is significantly different from other speakers, since that's part of my regression analysis that I'm also doing.
To give you an idea of what I'm looking at, let's say that we interview a speaker and find out that they say the word 'bag' in a particular way and we take measurements of that. In year 1, I take 200 observations of this word, in year 2, I take 240 observations, and in year 3, I take 175 observations. Each observation has its own line in my excel sheet, who says it, what kind of word it is (noun, verb etc), what came before it, and so on. Now what I want to know is if the way that the person says 'bag' is significantly different in Year 1 compared to Year 2 compared to year 3.
The data is not normal, so ANOVA seems to be out, plus the data are unbalanced (so I have different numbers of observations at times A, B and C). I did think that Kruskal-Wallis would work, but that seems to only apply to group means while I'm just interested in comparing the value of X for one person at three different times.
In terms of stats packages, I have SPSS and R, although if the solution is with R, I'll need step-by-step instructions for it cause I'm a noob with it.
Any stats-aces out there able to help a brother out?