Chapter 9: Experiments Flashcards
Experiment
A research approach in which one variable is manipulated and the effet on another variable is observed
Independent Variable
Variable the researcher manipulates directly such as price, packaging distribution, product features, etc
Dependent variable
Variables one doesn’t directly control such as sales or customer satisfaction
Treatment Variable
The independent variable manipulated during and experiment to measure its effect on dependent variables.
Extraneous Variables
Factors one does not control but has to live with such as weather.
Causal Research
Research designed to determine whether a change in one variable likely caused an observed change in another.
A causal relationship must demonstrate three things:
- Concomitant Variation (Correlation)
- Appropriate Time Order of Occurrence
- Elimination of Other Possible Causal Factors
Concomitant Variation
A statistical relationship between variables. If A causes B, then any change in A will also cause a change in B.
Appropriate Time Order of Occurance
Temporal Sequentiality. Change in an independent variable occurred before an observed change in the dependent variable.
If A causes B,then A must occur before B.
Elimination of Other Possible Causal Factors
“If you eliminate the impossible, whatever remains, however improbable, must be the truth.” - Sherlock Holmes
Hard to prove that something else did not cause change in B.
If A causes B, then there are no other letters.
Validity
Degree to which an experiment actually measures what it is trying to measure.
Internal Validity
The extent to which competing explanations for the experimental results observed can bar ruled-out.
External Validity
The extent to which causal relationships measured in an experiment can be generalized to outside persons, settings, and times.
Laboratory Experiment
Conducted in an controlled setting. Advantages: -Ability to control all variable - greater internal validity Disadvantages: - External validity - Not transferable to the actual marketplace
Maturation
Refers to changes in subjects throughout the course of the experiment that are a function of time and include such things as getting older, hungrier, tired, and the like.
Instrument variation
Refers to any changes in measurement instruments that might explain difference in the measurements taken. Ex. Two interviewers.
Selection Bias
Systematic differences betwee- whoops
Testing Effect
Result from the fact that the process of experimentation may produceits own effect on the responses we observe. Ex: ACT
Regression to the Mean
Refers to the observed tendency of subjects with extreme behavior to move toward the average for that behavior during the course of an experiment. People want to try to answer the “right answer.”
Experimental Deign
I an experimental design, the researcher has control over one or more independent variables, and manipulates one of more independent variables.
Non-experimental Design
Involve no manipulation and typically are referred to as “ex post facto” (after the fact) research.
“X”
Independent Variable
“O”
Dependent Variable