Multiple correlation is an implication of
multiple regression. There is a squared multiple correlation coefficient (R2) that
arises as a result of multiple regression. It can also be obtained by combining
simple correlation coefficients, obtaining partial correlation coefficients of
several orders, and finally get to R. But the question referred to SIMPLE
(BIVARIATE) correlation of each predictor with the outcome.
Hector
From: SPSSX(r)
Discussion
Sent: 01 January 2010 13:59
To: [hidden email]
Subject: Re: Regression or
correlation
But aren't multiple correlation and multivariate
regression basically the same thing?
Your friend is plain wrong. The different subscales are
correlated among them, and each probably predicts only part of the variance
in job success. Using the various subscales will cover more variance, may
predict better, and may also reveal the different weight of the subscales in
explaining JB. The subscale with the highest bivariate correlation may
ultimately have a lower regression coefficient. Your friend could be right if only one subscale has a high
correlation and all the others have not, but that is not likely to be the
case. Finally, remember than prediction is a probabilistic affair. You
cannot predict INDIVIDUAL job success: what correlation or regression may
tell you is the EXPECTED job success of a GROUP of people sharing the same
value of predictors. Likewise, smoking is a predictor of lung cancer, but you
cannot predict lung cancer for specific individuals: some smokers live to
their 90s, and some non-smokers get lung cancer anyway. You can only predict
that the RELATIVE FREQUENCY of lung cancer would be much higher among smokers
than non-smokers (assuming all are representative of the general population:
the prediction may break down if a majority of non-smokers, and a minority of
smokers, happen to be coal miners or some such, which makes them more likely
to breath in toxic substances causing lung cancer). In the latter case (coal
mining as a secondary predictor) including occupation in the regression
equation would help separate the two as independent causes of lung cancer. Hector From: SPSSX(r) Discussion
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