I understand the difference between partial correlation and semi-partial and zero-order correlation. This terminology makes sense to me in that the partial correlation of X and Y partials out the effect of one or more variables from both X and Y, and semi-partial correlation only partials out the effect of one or more variables on either X or Y (i.e., it only partially partials; i.e., it semi-partials).
For example, SPSS labels the semi-partial correlation as part correlation. This is the source of some confusion to students encountering this output for the first time.
- Why is the semi-partial correlation sometimes called the "part correlation"?
- What is the etymology of the term "part correlation"?