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Classifying strength of correlation

If +.75 represents a "strong" positive correlation, where does the concept of a "strong" correlation begin?

For example, is +.67 a strong correlation?

How about .5?

How about .42?

How about .3?

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This is a good question. Often, we go by conventions that have been around for a long time, basically stating that a correlation above .6 or .7 indicates a strong correlation, one above .4 indicates a moderate correlation, and one below .3 indicates a weak correlation. These are the types of descriptions you may see in textbooks, and you see that there is some variation in them (there's really no hard and fast rule about what constitutes s 'strong' correlation, but several authors act as though there is).

The thing to keep in mind is that when we're dealing with real experiments, instead of summaries of analyses in ...

Solution Summary

The expert explains what values of Pearson's r (correlation coefficient) correspond to strong, medium, and weak relationships using explanations of r squared (effect size).