Basic Experiment Flashcards
The variable which is changed or altered to try and find an effect
Independent (Manipulated) variable
The result or outcome due to the independent variable
Dependent (Measured) variable
Occurs in an experiment when the kinds of participants in one level of the independent variable are systematically different from those in the other
Selection Effect
An experimental design technique in which participants who are similar on some measured variable are grouped into sets - the members of each matched set are then randomly assigned to different experimental conditions
Matched Groups
Which type of design involves different groups of participants being placed into each level of the independent variable
Independent Group Designs
Participants are randomly assigned to independent variable groups and are tested on the dependent variable once
Posttest Only Design
What is the main disadvantage of Independent Group Designs?
Needing lots of participants
Which type of design involves one group of participants where each person is presented with all levels of the independent variable and are measured on the dependent variable each time
Repeated Measure Design
What are some of the advantages of a Repeated Measure Design?
Fewer participants needed
Extremely sensitive to statistical differences
Ensure participants will be equal
Error variance is reduced because people serve as their own control group
How might presenting multiple levels of the independent variable to a single group might negatively effect the dependent variable? (Order Effects)
Practice Effect - participant may get better with each level
Fatigue Effect - participant might get tired
Contrast and carry over effects - contamination carries over from one condition to next
Presenting levels of the independent variable to participants in different orders so that any order effects should cancel each other out when all data are collected
Counterbalancing
What is complete counterbalance?
All possible condition orders are represented
What is partial counterbalance?
Only some of the possible conditions orders are represented
Dependent variable is measured prior to the experimental manipulation
Pre-Test
Participants are randomly assigned to at least two groups and are tested on the key dependent variable twice - once before and once after exposure to independent variable
Prettest/Posttest Design
