I have been teaching statistics and associated topics (measurement, research design) for 37 years and have contributed to the methodological literature on such matters. During that time I have managed to get along without knowing or caring very much about a variety of techniques, most notably exploratory data analysis, Bayesian inference, expected values of mean squares, and item response theory. In the essay that follows I talk about another one: semi-partial correlations.
Knapp, Thomas R.
"Semi-Partial Correlations: I Don't Need Them; You Can Have Them,"
Mid-Western Educational Researcher: Vol. 9:
4, Article 4.
Available at: https://scholarworks.bgsu.edu/mwer/vol9/iss4/4