211 Ch. 10

one group of participants, measures on pretest, treatment, posttest, not good!!

threat to internal validity, when an observed change in an experimental group could have emerged naturally over time

threat to internal validity, occur when a "historical" or external event occurs to everyone in the treatment group, must occur between manipulation and measuring of DV

threat to internal validity, regression toward the mean, any extreme finding is likely to be closer to its own typical mean/level next time it is measured

threat to internal validity, when people drop out of a study before it ends

threat to internal validity, kind of order effect, scores have changed over time because participants have taken the test more than once

threat to internal validity, when a measurement tool changes over time from having been used before

threat to internal validity, when researcher's expectations influence their interpretation of results

threat to internal validity, when participants guess what the study is supposed to be about and change behavior in expected direction

neither participants nor researchers know who is getting which treatment

when people improve, but only because they believe they are receiving a valid treatment

finding than an IV did not make a difference in DV, that there is no significant covariance

all scores are at the high end

all scores are at the low end

too much unsystematic variability, error variance

factors that can inflate or deflate person's true score on a dependent measure