Midterm 2 Flashcards
Interrater Reliability
Is there consistency from rater to rater
- cohen’s kappa
Alternative (parallel form) reliability
Is there consistency between forms of the test?
- correlation coefficient
Inter-item (internal consistency) reliability
Consistency between individual items and the total score?
- cronbach’s alpha
Test-retest reliability
Consistency between scores on tests given in two separate occasions?
- correlation coefficient
Representative reliability
Is the measure consistent across sub populations or groups of people?
- no stat test
Face validity
do the items on the scale appear to measure what you say they do?
panel of experts establish it
Content validity
Is the full content covered?
Criterion validity
How does the measure relate to an already known standard?
- Concurrent: correlate with existing measure of the construct
- Predictive: correlate with other traits that would be associated with what you are trying to measure
Construct validity
How well does the operational definition assess the underlying theoretical construct?
- Discriminative: does the measure differentiate between groups we’d expect to score differently?
- Convergent: do multiple measures of the same construct hang together or operate in consistent ways?
Probability Sample
RANDOM generalizable
Non-Probability Sample
Not random, not generalizable
simple random sample
totally random, computer generator
systematic sample
every Kth element, random starting point
stratified sample
population put into subgroups and then randomly selected from each group
cluster sample
researcher obtains a list of clusters not individuals, clusters are randomly sampled
convenience sample
whoever is willing to
purposive sampling
sample is selected from predetermined criteria
snowball sample
ask for referrals
quota sample
try and get a sample that resembles the population (you just go convenience until you meet that criteria)
distribution of sample means
if we take a sample enough time, the means should form a normal curve
standard error
an estimate of the deviation of a summarizing measure from the true population parameter
margin of error
a value that tells us how close to truth the estimate is
purposes of descriptive research
- exploration - curiosity
- description - current state
- explanation - why/how
- feasibility or complexity
survey research
- interviews
- questionnaires
fairly inexpensive, anonymous, far reaching
correlational
- cross sectional - group differences at a single point in time
- longitudinal - assess changes over time for one group
longitudinal studies
- trend: changes in population over time
- cohort: study people over time w common characteristic (repeated cross sectional, not necessarily the same people)
- panel: follow same group of people over time
observational research
- naturalistic - continuous, take notes about everything going on, no preset operational definitions
- systematic- behavior checklist or time sampling
experimental
- pretest, treatment, posttest, control group, random assignment
one shot
treatment, posttest
one shot pretest-posttest
pretest, treatment, posttest
pretest-posttest control group
random: pretest, treatment, posttest
vs.
random: pretest, posttest
posttest only
random: treatment, posttest
vs.
random: posttest
internal validity
can confidently attribute results to the IV (no lurking/confounding variables)
external validity
can confidently generalize results to other people
threats to internal validity - selection bias
other things in common in sample
threats to internal validity - history
Other confounding factors occurring simultaneously
threats to internal validity - maturation
People change over time
threats to internal validity - testing
People get better when tests are repeated
threats to internal validity - instrumentation
Changes to scoring method
threats to internal validity - mortality
attrition, people leaving studies who have similar attributes
threats to internal validity - statistical regression
regression toward the mean, bias only includes the most extreme results (ceiling/floor)
threats to internal validity - diffusion of treatment/contamination
participants in groups communicate
threats to internal and external validity - experimenter expectancy
expectancy affect, experimenter behavior leads subject behavior
threats to external validity - multiple treatment interference
Participants receive additional treatments not part of the study
threats to external validity - Reactive Arrangements (Hawthorne Effect)
Subjects are aware they are being studied
threats to external validity - pretest sensitization
Pretest changes the nature of the treatment, influences performance on posttest
