7 Experimental Designs Flashcards
Experimental design refers to how participants are allocated to the different groups in an experiment.
Experimental Designs
Administer a memory test to all 30 subjects before the regular experiment started
obtain baseline measure
- used to form pairs of subjects that had equal or very similar scores.
Baseline scores
Pairs of participants are matched in terms of key variables (age, or socioeconomic status). One member of each pair is then placed into experimental group and the other member into control group
Matched Groups Design
Same participants take part in each condition of the independent variable.
Each condition of the experiment includes the same group of participants.
Within-groups/within-subjects design
Within-subjects/Repeated Measures Design
Risk in a within-subjects design.
30 subjects learn a large number of items with 5 repetitions and then learn one repetition. Proficient in learning/boredom/fatigue with the task
General Practice Effects
- The experimenter faces the difficulty of determining the order in which treatments should be given to subjects.
- Randomization- drawing names out of a hat/random-number table/computer to order conditions randomly.
Controlled through Counterbalancing
- Growing experience not due to a particular condition
- Scores get better and better
- Scores get worse and worse
Practice Effects
- Due to a particular condition or order of conditions
- Drugs: 0.1, 1, 3, 10, 100 mg
- Lighting: Dim, Medium, Bright
- Bright, Medium Dim
Carryover Effects
There is one Independent variable with 2 or more levels.
Psychologist wants to know what type of spokesperson makes teenagers want to buy a product.
Multiple Groups Design
Two Independent Variables with 2 or more levels each.
The difference in time spent playing with toys that are used for building and toys that are not
Gender’s effect on a toy’s popularity.
Factorial Design
