[EMAIL PROTECTED] said on 3/6/03 3:43 AM: >Dear all, > >Is there a method available of comparing the output of the layers in a 3 way >contigency table. Specifically I wish to test if an association present >between a pair of categories in one layer is present in another, and their >relative strength. Layers are not of equal sample size. > >I have a hunch that the easiest way of doing this is to compare the ratio >observed/expected between layers. But is there a rigorous method of >comparing such ratios? > >A real world example: > >Each case in my data is an scientific article concerning marine turtles, >categorised by species involved, field of research and nationality of >author. I know that ignoring nationality there is a strong positive >association between research on green turtles and resarch on pathology. Is >this association independant of nationality? > >Thankyou in advance for any help.
Author named Kennedy, in a book on Log-linear analysis describes in detail, with examples, a method of examining single degree of freedom contrasts analogous to those you might want to analyze if it were an ANOVA situation. It is not available in any specific computer program, from what I can tell, but is quite easy to do by hand. I believe this is a correct citation of the book: Kennedy 1992 Kennedy, J. Analyzing qualitative data - log-linear anaysis for behavioral research. New York: Praeger. Paul . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
