Traits, types & psychometrics Flashcards
psychometrics=
the field of study concerned with the theory & technique of psychological measurement (how we measure, what are assumptions underlying etc)
Classic Test Theory: Basic idea?
basic psychometric theory that attempts to map constructs to data
Classic Test Theory: Fundamental idea> (6)
- construct under study has “true” score: ‘T’
- attempt to measure construct with X
- Try to get X as close to T as possible
- X+T= Error
- Error is due to fact, process of measuring has some impact on construct itself
- Known as “observational error”
CTT: Types of error> (5)
- Misunderstandings (e.g. when self-reporting)
- Idiosyncratic interpretations (e.g. neurodiverse)
- Distractions (e.g. when online survey)
- Time pressure (e.g. time of day, being in rush etc)
- Time of day, year etc
>error presumed to be randomly distributed; error averages out to 0 across measures
Personality data can be evaluated through 2 key concepts>
> reliability
validity
Evaluating personality data: (1) Reliability=
how consistent/dependable a particular measure is
Evaluating personality data: (1) Reliability> ways to consider/explore> (3)
> Test-retest reliability
Internal consistency
Inter-observer reliability
Evaluating personality data: (1) Reliability> (1) Test re-test reliability>
> Does the same measure give the same result each time?
Evaluating personality data: (1) Reliability> (1) Test re-test reliability> Limitations>
- not practical to access identical sample every time
- fatigue effect: different outcomes due to tiredness of participants
- familiarity: knowledge of survey may compromise data collection
Fatigue effect=
different outcomes due to tiredness of participants
Evaluating personality data: (1) Reliability> (2) Internal consistency>
Are different measures looking at the same underlying thing? (e.g. 5 items looking at different aspects of extraversion)
Evaluating personality data: (1) Reliability> (2) Internal consistency> tests/ methods>
> Split-half test: Ans to similar qns should correlate if split in half (however correlations are influenced by HOW items are split)
Cronbach’s alpha= statistical method for exploring these internal consistencies with a subscale
Evaluating personality data: (1) Reliability> (3) Inter-observer reliability>
> is there agreement in measurement between different researches observing same area of research?
to avoid bias, researchers observe the same behaviour INDEPENDENTLY & compare their data
Evaluating personality data: (1) Reliability> (3) inter-observer reliability> methods
1) Training observers in same observation techniques
2) Behavioural categories operationalised (objectively define what asking for from start)
Evaluating personality data: (2) Validity=
way of considering if the measure if measuring what you THINK it is measuring
Evaluating personality data: (2) Validity> Types of validity measures>
> criterion validity
construct validity
content validity
discriminant validity
ecological validity
face validity
Evaluating personality data: (2) Validity> (1) Criterion validity=
to what degree can the scale predictively measure constructs
Evaluating personality data: (2) Validity> (1) criterion validity> 3 types>
> convergent validity= compare results with established method (e.g. new questionnaire & established scale)
> predictive validity= does measure predict a relevant behaviour or task performance
> retrospective validity= how the measure correlates with past occurrence of such behaviour (e.g. measuring risky behaviour & access to hospital records)
Evaluating personality data: (2) Validity> (2) Construct validity=
is scale measuring what it claims to measure (e.g. is ‘arrogance’ measure exclusively measuring arrogance or narcissism aswell)
Evaluating personality data: (2) Validity> (2) Construct validity> Threats:
- mismatch between operational definition & construct
- researcher bias
- procedural errors
Evaluating personality data: (2) Validity> (3) content validity=
how much of construct is captured by the item (e.g. is it measuring ONE aspect of empathy (i.e. towards animals) or attempting to capture a GENERAL disposition)