PSY 0035 Lecture Notes - Lecture 16: Causal Structure, Internal Validity
Document Summary
Selecion threat to internal validity paricipants in two groups of the iv are systemaically diferent: if we randomly assign paricipants to dif levels of the iv, we can idenify the causal structure. Between subjects design: dif groups of paricipants exposed to dif levels of the iv, each paricipant experiences only one level of the iv. Postest only design: type of independent-group design; paricipants are tested on the. Dv only once, at the end: ater manipulaions of the iv. Pretest-postest design: paricipants are tested on the key dv twice, once before and once ater, beneit can see the diference in each paricipant and atribute the diference (before and ater) to the iv. Within subjects design: each paricipant exposed to all levels of the iv, paricipants are tested on the dv once ater exposure to each level. Order efect: within subject design, threat to internal validity, exposure to one condiion changes paricipants" responses to a later condiion.
