RM Chpt 8 and 9 Flashcards
(26 cards)
Varies along with the independent variable
Occurs when the effects of the independent variable and an uncontrolled variable are intertwined
Cannot determine which variable is responsible for the effect
Confounding variable:
Ability to draw conclusions about causal relationships from the data
Results can be attributed to the effect of the independent variable
Experiment must be designed and conducted so that only the independent variable can because of the results
Internal validity:
Comparing posttest-only and pretest-posttest designs
Mortality (attrition): Dropout factor in experiments
Assess equivalency of groups with small sample size
Used to select participants for the experiment
Basic Experiments
Participants participate in only one group
Independent groups design:
Comparisons are made between different groups of participants
Between-subjects design:
Participants are assigned to multiple groups
Repeated measures design:
Comparisons are made within the same group of participants
Within-subjects design:
Used in independent groups design to assign different participants to each of the condition
Repeated measures experimental design
Procedure in which same individuals participate in all of the groups
Random assignment:
Order of presenting the treatments affects the dependent variable
Order effect:
Performance improves because of the practice gained from previous tasks
Practice (learning) effect:
Performance deteriorates because the participant becomes tired, bored, or distracted from previous tasks
Fatigue effect:
Effect of the previous treatment carry over to influence the response of the next treatment
Carryover effect:
All possible orders of presentation are included in the experiment
Latin square: Constructed for using the technique to control for order effects without having all possible orders
Time interval between treatments
Choosing between independent groups and repeated measures designs
Complete counterbalancing:
Frequently use a confederate or accomplice Considerations for strength External validity of the study Ethics Cost
Straightforward manipulations
Staged manipulations
Used to measure aspects of human thought and behavior
Self-report measures:
Direct observations of behavior
Behavioral measures:
Recordings of responses of the body
Physiological measures:
Independent variable appears to have no effect on the dependent measure
Ceiling effect:
Problem that occurs when the task is so difficult that hardly anyone can perform well
Floor effect:
Informs purpose of the study to participants
Demand characteristics
Can control through the use of placebo effect
Used to assure external validity is maintained
Placebo groups
Research on expectancy effects
Solutions to the expectancy problem
Experimenter bias or expectancy effects
Participant is unaware of whether a placebo or the actual drug is being administered
Single-blind experiment:
Neither the participant nor the experimenter knows whether the placebo or actual treatment is being given
Double-blind experiment:
