Behaviors typically increase in frequency when which of the following occurs?

According to Michael Dawson in Embedded and Situated Cognition, the external world:

A: Does not provide information storage, but can manipulate it B: Is not related to managing information C: Manipulates information that is stored D: Can provide information storage E: A and B F: C and D

Professor X wants to make sure his study of gifted youngsters will get published, but he's worried that his findings could have been caused by something other than the independent variable, which was a new teaching method he introduced

He is concerned with the ________________ of his experiment. a. probability level b. external validity c. replication d. internal validity