1. I am using a measure of optimism in a research study. Describe two things you need to know to be sure that I have a reliable and valid measure of the construct of "optimism."

2. Describe evidence for one situational factor that has been shown to cause people to harm others.

Can you find two in here?

1. Reliability indicates the consistency of scores when give to same individuals (r approaches +1 and is >.90). It requires good level of objectivity.

A. Test-retest indicates stability over time.

B. Equivalent/alternate form indicates consistency over various forms of the same test.

C. Split-half indicates consistency within a test (even-odd items example).

Validity means that a test "measures what it claims to measure." Although valid test needs to be reliable, reliability does not ensure validity. Valid if it correlates with criterion measure (ACT scores vs. grades example).

2. How about war?