Regression artifact refers to the mathematical fact that
a. people who score above average on pretests tend to have lower scores on posttests, and those who score below average on pretests tend to increase their scores on posttests.
b. any participant's score on a pretest can be expected to be lower on a posttest, because of the law of averages.
c. participants who have extreme scores, high or low, on a pretest tend to have posttest scores that are even more extreme.
d. posttests are often unnecessary, since they tend to give, on average, the same results as those obtained on pretests.
Inferential statistics uses __________ to allow a researcher to test hypotheses, permit inferences
from sample to population and to evaluate the strength of relationships among variables.
A) probability theory B) levels of significance
C) multiple regression D) statistical significance
In addition to PsycINFO, what other data bases are mentioned in your text as being helpful in psychological research?
a. MEDLINE and SocINDEX
b. BioMed and PhilosophyINDEX
c. INASP and JSTOR
d. LexisNexis and PubMed
R-squared in multiple regression analysis is
A) always 20 percent. B) considered good if it is at least .50.
C) based on improvement over zero. D) never a helpful measurement.
Some experiments require observers to take many measures of the dependent variable over time and across participants. If they become better observers of the dependent variable during the course of the study, it produces a confound referred to as
a. instability.
b. unreliability.
c. instrumentation.
d. insensitivity.
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