Task 6. Setting up research & sampling Flashcards
1
Q
Population
A
- all possible participants that fit the criteria
2
Q
Sample
A
- smaller subgroup chosen from the larger population
3
Q
Generalization
A
- ability to apply findings of a sample to a larger population
- requires a representative sample
- one of the important factors for external validity
4
Q
Random sample
A
- every person in the population has an equal chance of being chosen, necessary for generalization, but difficult to obtain
5
Q
Nonrandom sample
A
- individuals chosen from a highly specialized subpopulation
6
Q
Internet research sampling
A
- nonrandom, highly specialized, large but not representative (only ppl w )
7
Q
Animal studies sampling
A
- strains need to be exactly the same, usually the exact same litter because any kind of genetic mutation can affect the results
8
Q
Factors to consider when acquiring a research sample
A
1) research setting: lab or field
2) special needs of research: screening
3) ethical guidelines: APA
9
Q
Volunteer bias
A
- individuals that volunteer fundamentally different from the ones that don’t, lowered external validity
10
Q
Situational factors of volunteers
A
- interesting / important topis
- rewards
- personal acquaintance with the researcher
11
Q
Internal validity and volunteerism
A
- volunteers are trying to please the experimenter, altering the results
- volunteerism can serve as “motivation indicator”
12
Q
External validity and volunteerism
A
- WEIRD participant characteristics -> low generalizability
13
Q
Remedies for volunteerism
A
- making the appeals as interesting as possible
- make appeal as nonthreatening as possible
- state in what way the participants are important-> benefitting others
- if possible avoid stressful tasks
- personalized appeals
14
Q
Probability sampling
A
- each participants has a known probability of being in the sample -> ideally, all have an equal chance
15
Q
Representative sample
A
- closely matches the characteristics of a population
16
Q
Biased sample
A
- non-representative sample
17
Q
Sampling techniques (5)
A
- simple random: random selection of a certain # of individuals
- stratified: population divided into segments, each segment represented
- proportionate: conserve the percentage of the population segments
- systematic: every nth individual is included, random start
- cluster: picking a naturally occurring cluster of individuals, including the entire group (used together with simple random)
18
Q
What to keep in mind when determining Sample size
A
- smaller samples- controlled environment
- larger samples - many variables/uncontrolled variables
-amount of acceptable error
-expected magnitude of population proportions
19
Q
Economic sample
A
- enough participants to be valid, but no more
20
Q
Internal validity
- extraneous variables?
- confounding?
A
- ability of research design to adequately test your hypothesis / ability to adequately measure what its supposed to
-shown in variation in independent variable - threatened by extraneous variables that can provide alternative explanations and rival hypotheses
- confounding: merging of two or more variables to the point that it is impossible to separate their effects, affects overall correlation
21
Q
Threats to internal validity
general sources of confounding (7)
A
- history: special events occur between obs.
- maturation: performance affected due to aging/fatigue
- repeated testing
- instrumentation: missed errors in criterion/instruments
- statistical regression: extreme-result subjects selected for treatment tend to regress toward the mean upon retesting
- biased selection: groups not equivalent prior to intervention
- experimental mortality: loss of subjects during the research
22
Q
External validity
A
- results can be generalized for the population
23
Q
Threats to external validity
A
- reactive testing: subjects react to pretest and adjust
- interaction between participant selection bias and the IV: Jožek iz Špičkovine vs Maartje van Maasi
- reactive effects of experimental arrangements: being aware that one is a participant and that they are being studied
- multiple treatment interference
