For the research scenarios below, identify the threats to internal validity (e.g., selection, maturation, etc.) AND explain how the study findings could be affected by the threat.

A. When juveniles in the care of foster parents get into extreme trouble with the law, they are sent to Star House, a rehabilitative group home. Star House has a reputation for treating "the worst of the worst," a last stop for juvenile offenders before imprisonment. The rehabilitative program at Star House consists of a token economy, in which points are earned for appropriate social behaviors (e.g., attending school, proper hygiene, reading books, etc.) and lost for inappropriate behaviors (e.g., panhandling, sleeping in, cutting classes, etc.). Points can be exchanged for backup reinforcers, such as the opportunity to play video games, watch TV, or leave the home to attend special events. One year, information was collected on patients one month before entering the program and one month after leaving it. The typical patient stay at Star House was about 10 months. Results demonstrated that residents of Star House reduced the number of inappropriate behaviors and increased the number of socially acceptable behaviors from pre-test to post-test.

B. Wilma's parents and teacher were concerned about her noncompliance, so they consulted a behavior therapist. They all decided together that the first order of business was to gauge the extent of the problem. For the next week, her teacher recorded all instances of the target behavior at school and her parents recorded all instances at home. Noncompliance was defined a failure to respond to an instruction within 10 seconds. The resultant data indicated that, when asked to do something, Wilma was four times more likely to obey the instruction at home than at school. They concluded that the problem was considerably worse at school, and consequently they decided to employ a different behavioral procedure in each setting.