Suppose sandra has difficulty in concentrating while doing her homework. she decides to reward herself for reading 5 minutes without letting her mind wander. after a week of this, she decides to reward herself only when she reads for 10 minutes without distraction. finally, she is able to concentrate for 15 minutes at a time without distraction. sandra's ability to improve her study behavior is best considered an example of:

Sandra’s ability to improve her study behavior is best considered an example of "shaping".

Shaping includes an ascertained reinforcement of an "objective behavior". It utilizes operant conditioning standards to prepare a subject by compensating legitimate conduct and debilitating inappropriate conduct.  

Shaping includes efficiently fortifying progressive approximations to a desired conduct. In this case, Sandra fortifies her progressive approximations (examining for 5 minutes) of the desired conduct (considering for 15 minutes without diversion).

answer; i believe the correct answer is (8) eight.