Forrester Found a Strong Positive Relationship Between Participation in High

Forrester found a strong positive relationship between participation in high school extracurricular activities and community involvement as adults. He controlled for amount of college and the relationship between high school extracurricular activities and community involvement was negative for low college attainment, nonexistent for medium college attainment, and positive for high college attainment. Which type of elaboration analysis is this?

A) replication
B) explanation
C) interpretation
D) specification
E) extension