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201 FINAL TEST
Question | Answer |
---|---|
independent variable | the variable in the study that is manipulated by the researcher |
dependent variable | the variable in the study that is measured by the researcher |
control variable | manipulating the independent variable in an experiment that could affect the results of the study |
confound | an uncontrolled extraneous variable or flaw in an experiment |
control group | the group of participants that does not receive any level of of the independent variable and serves as a baseline in the study |
experimental group | the group of participants that receives some level of the independent variable |
internal validity | the extent to which the results of an experiment can be attributed to the manipulation of the I.V. rather than to some confounding variable |
time-order relationship | demonstrating a cause and effect relationship. |
elimination of alternative explanations | the difference between the mean is due only to the I.V, anything else represents a threat to the internal validity of the study |
posttest-only control group design | an experimental design in which the dependent variable is measured after the manipulation of the I.V. |
non-equivalent control group | a design in which at least two nonequivalent groups are given a pretest, then a treatment, and then a post-test measure |
floor effects | a limitation of the measuring instrument that decreases its capability to differentiate between scores at the bottom of the scale |
ceiling effect | a limitation of the measuring instrument that decreases its capability to differentiate between scores at the top of the scale |
experimenter effects | a threat to internal validity in which the experimenter, consciously or unconsciously, affects the results of the study |
participant effect | a threat to internal validity in which the participant, consciously or unconsciously, affects the results of the study |
placebo control group | a group or condition in which participants believe they are receiving treatment but are not |
single-blind experiment | an experimental procedure in which either the participants or the experimenters are blind to the manipulation being made |
double-blind experiment | an experimental procedure in which neither the experimenter or participant knows the condition to which each participant has been assigned-both parties are blind to manipulation |
external validity | the extent to which the results of an experiment can be generalized |
independent sample t-test | a parametric inferential group for comparing sample means of two independent groups of scores |
null hypothesis (ho) | the hypothesis predicting that no difference exists between the groups being compared |
alternative hypothesis (ha) | the hypothesis that the researcher wants to support, predicting that a significant difference exists between the groups being compared |
generalize to different samples | get the same results if you repeat the same study with a different sample (from the same population)- replication |
generalize to different populations | get the same results if you repeat the same study with a sample from a different population |
generalize from different settings | get the same results under different conditions |
type one error | an error in hypothesis testing in which the null hypothesis is rejected when it is true |
type two error | an error in the hypothesis testing in which there is a failure to reject the null hypothesis when it is false |
mean | a measure of central tendency; the arithmetic average between groups or variance within groups |
standard deviation | a measure of variation, the average difference between the scores in the distribution and the mean of the scores or the sq. root of the average squared deviation from the mean |
z-score | a number that indicates how many standard deviation units a raw scores is from the mean of a distribution |
percentile score | a score that indicates the percentage of people who scored at or below a given raw score |
sample | the group of people who participate in a study |
population | all of the people about whom a study is meant to generalize |
third variable problem | the problem of a correlation between two variables being dependent on another (the third) variable |
construct validity | the degree to which a measuring instrument accurately measures a theoretical construct or trait that it is designed to measure |
reliability | an indication of the consistency or stability of a measuring instrument |
internal consistency | all the items are measuring the same construct |
test-retest reliability | a reliability coefficient determined by assessing the degree of relationship between scores on the same test administered on two different occasions |
convergent validity | the test is strongly correlated with other measures of the same construct |
discriminate validity | the test is not strongly correlated with tests measuring different constructs |