PSYCO212 Lecture Notes - Lecture 31: Random Assignment, Quasi, Internal Validity

• School: University of Alberta
• Department: Psychology
• Course: PSYCO212
• Professor: Poliana Barbosa

Document Summary

With internal validity, you are controlling for all possible third variables by using random assignment. Quasi experiment: a study that is similar to an experiment except that the researchers do not have full experimental control, they cannot randomly assign the participants. Nonequivalent control group design: a quasi-experiment that has at least one treatment group and one comparison group, but participants have not been randomly assignment to the two groups. The head start study: head start is a government-funded, early-childhood education program in the u. s that gives a quality preschool experience to children from economically poor homes. Education researchers compared the academic performance of children in the program and the children not in the program. The groups has the same score in a pretest achievement test, but differ in economic status (head starters had a lower income). The results showed that the students who had been in head start had lower scores on the sats than the other group.