day 13 Flashcards
(12 cards)
Advantages and Disadvatanges of between subjects design
Advantage, no carry over effects. Disadvantages, Comparability of groups, sample size needed when the effect size is small.
Obtaining equivalent groups
Random assignment, matching, within-subjects design.
Advantages and disadvantages of within subjects design
Advantages- control for the subject variables, statistical power. Disavatages, carryover effects(effects of an experiment carries over to another condition, influnce the behavior.
Types of carry over effects
Order effects, practice effects(when subjects is asked to repeat something several times they are most likely getting better with each time); fatigue affects (boredun, tired, with regard to mood that could shift a subjects scores).
Controlling for carry over effects
Counterbalancing, randomizing for some experiments, time between conditions.
Quasi experimental designs
No manipulation of the Iv common in applied research.Issue of designing and measuring a quasui-IV, Issue of sample selections. Issue of approriate control group. Quasi doesnt reflect on the population but more about the manipulation of the Iv
Additional design considerations
selection of control conditions, number of independent variables to manipulate, possible confounds.
Strategies for avoiding experimental error
Pilot testing, automating experiments, multiples experiments (replications, converging operations)
Thre types of T -test
Single sample T -test, independent sample t-test (between subjects) Paired samples (related samples,repeated measures)
Related sample t-test
Like a single sample t-test using the difference between scores instead of a signle score.
Cohens D is easy for paired sample t-test
The values need to calculate cohens D is SD and mean difference.
Mixed design
One or more between-subjects manipulation and one or more with subjects manipulation common in psychological research.
