Nonexperimental studies always contain a threat to internal validity, which means that these studies cannot establish unambiguous cause-and-effect relationships.

In an observational study of autistic children, you record how much time each child spends playing alone during a 30-minute observation period. This is an example of the ____ method of quantifying behavior.

Last fall, a state college introduced a one-week study skills course for new freshmen students. At the end of the academic year, the college compared the grades and dropout rate for their freshmen with the corresponding measurements for freshmen at a neighboring state college. This study is an example of a ____.

A researcher comparing depression scores before and after treatment in one group of clients, is using a(n) ____.

The direction of a relationship between variables is indicated by the ____.

In a distribution with a mean of M = 36 and a standard deviation of SD = 8, a score of 40 would be considered an extreme value.

Counting how many times a child exhibits disruptive behavior during a 30-minute observation period is an example of measuring behavior using the duration method.

Holding a participant characteristic (such as age or gender) constant strengthens ____ and weakens ____.

One responsibility of the Institutional Review Board (IRB) is to ensure that ____.

The Pearson correlation is used when both scores are _____.