Dear Diane,
your physician boss is right, in my view, especially if you're concerned
with health research as in your depression correlations. Suppose you get
r=0.30 between depression and job satisfaction, with p<.0001. This
means that 0.30 squared=0.09 or 9% of the variation in depression
scores is explained by job satisfaction (or insatisfaction, I presume
it's preferable to say). Assuming the confounding influence of other
factors has been controlled away, this is not a minor discovery. For
instance, it tells you that 91% of differences in depression scores are
unrelated to job satisfaction; i.e. giving everyone a satisfying job
would reduce the variability of depression scores by only 9%. In terms
of regression coefficients beta (deducible from r and the variables'
variances), it tells you what reduction in depression scores you can
expect if you improve job satisfaction scores in a given measure. This
may be translated into millions of dollars saved by employers and HMO
due to lower depression cases among employees, and this benefit compared
to the cost of improving job satisfaction determining factors (whose
effects on job satisfaction are determined by a different regression
equation). Of course, life would be easier if a single factor would
explain 100% of your problem, but usually many factors intervene, and
thus amny of them would explain only a fraction of the total. If the
estimate of that fraction has a low margin of error, the conclusions
thereof may be useful in spite of the small percentage of variance
explained.
Hector Maletta
Universidad del Salvador
Buenos Aires, Argentina
"Cohen,Diane" wrote:
>
> Dear Listers,
>
> I have run some social science correlations, all of which are significant (p=<.001). They have to do with correlations between total depression scores and job satisfaction scores, anxiety scores and life satisfaction scores, etc. I now need to know what the 'r' cut off is in determining which of these correlations are really worth reporting. My business major son says r's below .45 are not very interesting or worthwhile...my boss (a physician) says all are worthwhile  whether .131 or .777. What do you social science folks say??
>
> Diane
