research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable).
What is an experiment
the outcome factor; the variable that may change in response to manipulations of the independent variable.
what is the dependent variable
Includes all of the individuals in the group to which the study applies
what is population
an experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo.
What is double-blind study
Select people to participate in research in such a way that everyone in the population has an equal chance of being included
what is random sample
in an experiment, the group exposed to the treatment, that is, to one version of the independent variable.
What is the experimental group
A research design in which the participants don’t know which treatment group—experimental or control—they are in
what is single-blind study
the arithmetic average of
a distribution, obtained by adding the scores and then dividing by the number of scores.
What is the mean
assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups.
What is random assignment
Whether or not an experiment can be repeated
what is reliability
in an experiment, the group not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.
What is the control group
the middle score in a distribution; half the scores are above it and half are below it.
Median
the extent to which a test or experiment measures or predicts what it is supposed to.
what is validity
experimental results caused by expectations alone
what is the placebo effect
the experimental factor that is manipulated;
what is the independent variable
the most frequently occurring score(s) in a distribution
What is the mode
a factor other than the independent variable that might produce an effect in an experiment.
what is the confounding variable
Individuals who seem to be participants but in reality are part of the research team, trick real participants into thinking they are fellow participants
what are confederates
Designed a lot like a true experiment except that the participants are not randomly assigned to experimental groups
what is a quasi experiment
A definition of the variable in terms of precisely how it is to be measured
what is the operational definition