Final Designs Flashcards
Between-subjects design (p168, 213)
Aka independent groups design
An experiment in which different subjects are assigned to each group. Participants are randomly assigned to the various conditions so that each participates in only one group. Comparisons are made between different groups of participants.
Matched pairs design (p174)
A method of assigning subjects to groups in which pairs of subjects are first matched on some characteristic and then individually assigned randomly in groups. People are first matched on a participant variable such as age or personality trait. The goal is to have the same equivalency of groups ( that you get with a repeated measures design) without needing the same participants in both conditions.
Posttest-only design (p163)
A true experimental design in which the dependent variable(posttest) is measured only once, after manipulation of the independent variable.
Researchers must 1) obtain two equivalent groups of participants
2) introduce the independent variable, 3) measure the effects of the independent variable on the dependent variable
Pretest-posttest design (p164)
A true experimental design in which the dependent variable is measured both before(pretest) and after(posttest)manipulation of the independent variable. This design makes it possible to ascertain that the groups were, in fact, equivalent at the beginning of the experiment. This is not usually necessary if participants have been randomly assigned to the two groups.
Solomon four-group design (p166)
In this design half the participants receive only the posttest, and the other half receive both pretest and posttest. This design assesses the impact of the pretest directly with a combination of both. If the is no impact of the pretest, the posttest scores will be the same in the two control groups ( with and without the pretest) and in the two experimental groups.
Repeated measures (aka within-subjects) design (p168, 213)
An experiment in which the same subjects are assigned to each group. Participants are in all conditions. Each participant is measured after receiving each level of the independent variable. Comparisons are made within the same group of participants (subjects) an advantage is that fewer research participants are needed. They are also extremely sensitive to finding statistically significant differences between groups. The major problem with this type is that different conditions must be presented in a particular sequence. (See order effect, part time effect, fatigue effect)
Factorial design (p204)
Designs with more than one independent variable (or factor). A design in which all levels of each independent variable are combined with all levels of the other independent variables. A factorial design allows investigation of the separate main effects and interactions of two or more independent variables. The simplest factorial design is 2x2 factorial design. A factorial design allows you to test for interactions. There are two or more independent variables.
IV X PV design (p208)
A common type of factorial design that includes both experimental (manipulated) and nonexperimental(measured or no manipulated) variables. Allow researchers to investigate how different types of individuals (i.e., participants) respond to the same manipulated variable. These “participant variables” are personal attributes such as age, gender, ethnic group, personality characteristics, and clinical diagnostic category. Participant variables are sometimes are sometimes also referred to as subject variables or attribute variables but they’re all the same thing.
Mixed factorial design (p213)
A design that includes both independent groups (between-subjects) and repeated measures (within-subjects) variables. A combination of independent groups and repeated measures.
Control series design (p233)
An extension ( improvement) of the interrupted time series quasi-experimental design in which there is a comparison or control group. The “improvement” is the addition of a control group.
Interrupted time series design (p233)
A design in which the effectiveness of a treatment is determined by examining a series of measurements made over an extended time period before and after the treatment is introduced. The treatment is not introduced at a random point in time.
Multiple baseline design (p223)
Observing behavior before and after a manipulation under multiple circumstances (across different individuals, different behaviors, or different settings). The effectiveness of treatment is demonstrated when a behavior changes only after the manipulation is introduced. To demonstrate the effectiveness of the treatment, such a change must be observed in multiple circumstances to rule out the possibility that other events were responsible.
No equivalent control group design (p230)
A quasi-experimental design in which nonequivalent groups of subjects participate in the different experimental groups, and there is no pretest. This design employs a separate control group, but the participants in the two conditions -the experimental group and the control group- are not equivalent. The two groups are not the result of random assignment.
Nonequivalent control group pretest-posttest design (p231)
A quasi-experimental design in which nonequivalent groups are used, but a pretest allows assessment of equivalency and pretest-posttest changes. One of the most useful quasi-experimental designs. Not a true experimental design (like the pretest-posttest design) because assignment to groups is not random; the two groups may not be equivalent. Does have the advantage of knowing the pretest scores therefore can see whether groups were same on priestess. Can look at changes in scores.
One-group post-test only design (p226)
A quasi-experimental design that has no control group and no pretest comparison; a very poor design in terms of internal validity. “One-shot case study”
