[EMAIL PROTECTED] (Jan) wrote in message news:<[EMAIL PROTECTED]>... > A very basic statistical problem, i fear, but i can't get it solved. I > have collected data on the occurence of pathology at female ovaries, > and graded them according to the severity. Left: 1: 91, 2: 31, 3: 7, > 4:3; Right: 1:66, 2:28, 3:6, 4:3; totals: left: 132, right: 103. All > data are collected on females who present with fertility problems > (which could case a certain bias). To the best of my knowledge, no-one > has documented a 50/50 spread between left and right (normally there > should be no pathology! though some asymptomatic women are probably > around). Q: 1/Which test should I use to compare left vs right againsi > grading (if i can due to the difference in spread among grades?!)? > 2/Can I say that left is significantly more affected than right? > (which test, based on which presumptions)? Thanks a lot!!
The data should be organized in a 5 by 5 contingency table F in which F_ij, i,j = 0...4, is the number of women whose left and right ovaries had severity scores i and j, respectively, where 0 indicates no pathology. It is not clear what the given values 1 2 3 4 L 91 31 7 3 R 66 28 6 3 are. Are they the leftmost column F_i0 and the topmost row F_0j, omitting F_00? Or perhaps the row and column sums, F_i+ and F_+j, omitting F_0+ and F_+0? In any case, the question is about the nature of any asymmetry in F. . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
