At the most simple level, my question is which descriptive statistics are the most kosher for reporting when using nonparametric tests like Mann-Whitney and Kruskall-Wallace?
My reason for asking this is a recent kerfluffle over some stats reporting I did years ago for a paper in STEM education. We had several variables being tested, but these variables faced a few issues when it came to applying ANOVA and t-tests: some variation from normality, uneven n's, etc. Most of the normality problems were due to floor effects since these were time measures and could not be negative. For consistency, we ended up doing nonparametric tests throughout the paper: 3-way Kruskall-Wallis then post hoc Mann-Whitney (with adjustments). When it came to publishing decisions, we decided to report the means and SDs along with the test statistics.
Half a decade later, we've received some complaints that we should have reported medians instead. From what I've read and seen, my knowledge as a stats consultant working in education and STEM research says that it's debatable which is better to report. Medians make sense because the tests are median-based. However, my argument was and still is that the data was mostly normal and that the mean and standard deviation gives more information.
Of course, the sensible answer is to report mean, median, and SD. We didn't because the table was already at the point of illegibility and the authors refused to add a second table.
So, is there any consensus here? Published opinions? Or is this a horrible, unending debate like the vi versus emacs debates in computer science?
-- kate
My reason for asking this is a recent kerfluffle over some stats reporting I did years ago for a paper in STEM education. We had several variables being tested, but these variables faced a few issues when it came to applying ANOVA and t-tests: some variation from normality, uneven n's, etc. Most of the normality problems were due to floor effects since these were time measures and could not be negative. For consistency, we ended up doing nonparametric tests throughout the paper: 3-way Kruskall-Wallis then post hoc Mann-Whitney (with adjustments). When it came to publishing decisions, we decided to report the means and SDs along with the test statistics.
Half a decade later, we've received some complaints that we should have reported medians instead. From what I've read and seen, my knowledge as a stats consultant working in education and STEM research says that it's debatable which is better to report. Medians make sense because the tests are median-based. However, my argument was and still is that the data was mostly normal and that the mean and standard deviation gives more information.
Of course, the sensible answer is to report mean, median, and SD. We didn't because the table was already at the point of illegibility and the authors refused to add a second table.
So, is there any consensus here? Published opinions? Or is this a horrible, unending debate like the vi versus emacs debates in computer science?
-- kate