L6 Lab Experimental research Flashcards
Why an experiment?
To test causality: cause and effect relationship among variables
Characteristics of causality
‒ X and Y co-occur (correlation)
‒ A logical explanation for the effect of X on Y is needed
‒ X proceeds Y in time
‒ No other cause (Z) explains the co-occurrence of X and Y
What is an experiment?
Data collection method where one or more IVs are manipulated to measure the effect on the DV, and where you control for other causes
Independent variable
Variable that is manipulated (aka the “treatment” variable)
‒ E.g., price, packaging, degree of advertising, employee bonus, …
‒ Ways to manipulate:
» Presence vs. absence (e.g., bonus vs. no bonus)
» Frequency (e.g., high bonus vs. low bonus vs. no bonus)
» Type (e.g., punishment vs. reward)
Dependent variable “y” or “o”
Variable that is measured
‒ E.g., sales, click-through rate, purchase intention, attitude, motivation, performance,…
‒ Can be nominal, ordinal, interval, or ratio
Extraneous variable
Every possible variable that can influence the DV, other than the IV
‒ E.g., store location, age, gender, culture, …
Internal validity
To what extent does the research design permit us to say that the independent variable causes a change in the dependent variable
External validity
To what extern are the results found in the lab setting transferable or generalizable to actual organizational or field setting.
- Without internal, no external validity
Confound
A variable (Z) that threatens internal validity - roadblock
Lab experiment
Artificial setting to have as much control as possible over the manipulations (incl online experiment)
Field experiment
Natural environment where manipulation is possible
− Problems with randomization
− Problems to exclude external influences
Threats to internal validity
- history effect
- maturation effect
- testing effect
- instrumentation effect
- selection bias effect
- mortality effect
- statistical regression effect
History effect
Events/factors outside the experiment have an
impact on the DV during the experiment
Maturation effect
Biological/psychological of participant changes over time
- growing older
- getting hungry
- getting tires
- getting bored
Testing effect
Prior testing affects the DV