EXPERIMENTAL RESEARCH. How do you establish causality? what causes something else to occur? Lazarsfeld provided three criteria: 1. Covariation – two are related 2. Time order – cause before outcome 3. Elimination of likely third variables. Establishing causality.
How do you establish causality?
O- X - O experimental group (pretest-posttest)
O - . - O control group (pretest-posttest)
. X - O posttest-only experimental group
. . - O posttest-only experimental group
Multiple variables are examined