Chapter 13 Quasi-experiments and small-N designs experimental psychology exam 3

Quasi variable jane –

serves the same purposes as an independent variable but researchers do not have full control over it

Quasi experiment jane  –

a little bit of each leans a bit more towards correlation (association) then experiments

Quasi experiment book -

 A study similar to an experiment except that the researchers do not have full experimental control (e.g., they may not be able to randomly assign participants to the independent variable conditions).

quasi-independent variable book-

A variable that resembles an independent variable, but the researcher does not have true control over it (e.g., cannot randomly assign participants to its levels or cannot control its timing).

nonequivalent control group posttest-only design

A quasi-experiment that has at least one treatment group and one comparison group, but participants have not been randomly assigned to the two groups.

nonequivalent control group posttest-only design Example -

NUDGING PEOPLE TOWARD ORGAN DONATION

nonequivalent control group pretest/posttest design

A quasi-experiment that has at least one treatment group and one comparison group, in which participants have not been randomly assigned to the two groups, and in which at least one pretest and one posttest are administered

nonequivalent control group pretest/posttest design Example -

The psychological effects of cosmetic surgery

interrupted time-series design

A quasi-experiment in which participants are measured repeatedly on a dependent variable before, during, and after the “interruption” caused by some event.

interrupted time-series design Example -

Logic 1-800 and suicide rates

nonequivalent control group interrupted time-series design -

A quasi-experiment with two or more groups in which participants have not been randomly assigned to groups; participants are measured repeatedly on a dependent variable before, during, and after the “interruption” caused by some event, and the presence or timing of the interrupting event differs among the groups.

Nonequivalent control group interrupted time-series design Example -

investigating the effect of drug marketing on opioid abuse

Quasi-Experimental designs sacrifice _______ validity in exchange for ______ validity

Quasi experimental designs sacrifice internal validity in exchange for external validity

Why are reversal designs important?

Sometimes individuals need treatment for life. You need to show that without the treatment the client regresses for insurance, evaluative, and efficiency purposes.

You have baseline then introduce treatment then take it away for a little bit of time then introduce the treatment for a little bit again and then you take it away again for longer and then you have treatment for longer

-          This is to establish that treatment is effective and without it the client will regress and to show the insurance company’s the need for treatment

Small-N designs

A study in which researchers gather information from just a few cases

Characteristics of Small-N designs

1.      Each participant is treated separately. _______ ______are almost always repeated-measures designs, in which researchers observe how the person or animal responds to several systematically designed conditions.

2.       Data for each individual are presented

3.      Careful designs enable researchers to compare each individual during treatment periods and control periods.

4.      These designs are often used in therapeutic settings, to confirm that a treatment works for an individual person