Week 5 Flashcards
What are the control techniques used at the beginning of an experiment?
- Random assignment.
2. Matching.
List the methods of matching?
- Holding variables constant.
- Blocking (building extraneous variables into the design).
- Yoked control.
- Equating participants.
What is yoked control?
Participants are yoked (joined together) by receiving the same stimuli or conditions.
What are the control techniques used during the experiment?
- Counterbalancing.
- Control of participant effects.
- Control of experimenter effects.
What are methods of counterbalancing?
- Randomised - Sequence order is random for each participant.
- Intrasubject - Sequence order is is varied across all participants.
- Complete - Removing sequences, assigning different treatments to different groups.
- Incomplete - Different groups have different sequences.
What are the participant effect control methods?
- Double-blind placebo method - Participants AND researchers are unaware of treatment condition.
- Deception - Giving the participant a false reason for the experiment (lie to them).
- Control of participant interpretation.
List the 3 common experimenter effects.
- Recording errors - Fixed by using mechanical or electronic data collection devices (no human dumb-dumbs).
- Experimenter attribute errors - Fixed by controlling experimenter attributes that could effect the IV or DV.
- Experimenter expectancy errors - Fixed by using double-blind methods or automation (no human dumb-dumbs).
What is equating participants?
Matching participants on variables that need to be controlled (age, sex etc).
What are sequencing effects?
Occurs when the order of treatments in an experiment interact, and become confounding variables.
- Order sequence - Arises from the order of treatments administered.
- Carryover effect - One treatment affects another.
What are methods of controlling participant interpretation?
- Retrospective verbal reports (verbal reports after the experiment).
- Concurrent verbal reports (verbal reports during experiment).
- Sacrifice groups (stopped and interviewed during experiment).
- Concurrent probing (participants perceptions of experiment after completion of each trial).
- Think-aloud technique (Participants verbalise thoughts as they do the experiment).
What is experimental design?
The strategy used to investigate a research problem, needs to be ethical, feasible and methodologically robust.
What is weak experimental design?
Do not control for extraneous variables and provide poor evidence for cause and effect, might be the only design available.
What is strong experimental design?
Designs that control extraneous variables and provide good evidence for cause and effect. Generally have 3 following criteria: 1. Pretests. 2. Control groups. 3. Random assignment (RTC).
What are the some weak experimental design examples?
- One-group posttest only design.
- One-group pretest-posttest design (pre-post study).
- Post-test-only with non-equivalent groups design.
What are the 3 main categories of strong experimental design?
- Between participants - Different groups are exposed to different conditions with control group.
- Within participants - All participants receive all conditions with counterbalancing.
- Factorial - Two or more IV are studied to identify separate and collective effects on the DV.
