What makes a good theory?
- Theory is an explanation or model of how a phenomenon works
- use to make predictions for future events
- organize information in a meaningful way
- uses present info
- is testable (ie falsifiable)
- predictions arwe supported by research
- new studies support theory
- conforms to law of parsimony
- AKA Occam’s razor (simpler theories = better)
operational definition
- defines a variable in terms of specific procedures used to produce or measure it
- definition of variable itself
- ex. fatigue regularly vs. fatigue while driving (impairement)
what makes a good measurement
reliability
validity
reliability
always produce the same score when measuring the same thing
measurements won’t change over time
validity
- must be conceptually related to the property of study
- is it measuring what it needs to measure
types of measures
self-report
observational
psychological tests
self-report measures
- participants report on their own knowledge, beliefs, feelings, experiences, or behaviour
- a questionaire or interview (ex. likert scale)
Issues to consider with self-report measures:
- social desirability bias
– desire to make good impression - asking suggestive or leading questions
how to prevent social desirability bias
anonymity
overt
- behaviour we can directly observe
covert
hidden; undercover
ie. thoughts
Measures of overt behaviour
- observers record observable behaviour
- requires an operational definition of the behaviour you’re looking for
- observers must be trained to consistently code their observations (reliability)
issues with measures of overt behaviour
- just like the desirability bias in self-report measures, participants can change their behaviour when being observed
demand characteristics
cues in an experiment that tell the participant what behavior is expected
solutions to demand characteristics
- unobstructive measures
ex, instead of questionaires, ask them to do actions to assess mood
a measure obtained without disturbing the participant or alerting him or her that a measurement is being made. For example, a researcher may observe passersby in a public park from a nearby café and document their activities.
types of measures #3: psychological tests
Psychological tests:
- specialized tests designed by psychologists to measure particular variables
- personality tests
- intelligence tests
- neuropsychological tests (diagnose abnormal brain functioning)
Variable
Any characteristic that can vary
What are the types of measures
- Self report - observational - psychological tests
Rorschach inkblot test
A projective personality test in which individual interpretations of the meaning of a set of unstructured inkblots are analyzed to identify a respondent’s inner feelings and interpret his or her personality structure
check to see what parts of ink blot person focussed on
not used anymore because everyone knows about it
