SPRING Psychometrics and reliability

Question 1

what are psychometrics

Answer 1

measurement of the mind - stable characteristic of an individual
ie ability personality and atitude

Question 2

what should you consider with psychometrics

Answer 2

reliability and validity of the measure you are taking

Question 3

reliability

Answer 3

measure of consistency
true score + random error (design flaws)
-aim to minimise error and get as close to true score as possible

Question 4

validity

Answer 4

does the test measure what it is supposed to/reflect true to life constucts/abilities

Question 5

how can reliabiity be assessed

Answer 5

correlation (0-1)
if true score then consistent in
1- performance on diff parts of test
2- performance of same people on diff occasions
3- performance of same people by different testers

Question 6

general psychometric tests and reliability

Answer 6

IQ = 0.9
personality = 0.7
openended/subjective tests = 0.5
indirect = 0.2

Question 7

how can you test for reliability

Answer 7

test retest
parallel forms
inter item
inter rater

Question 8

what is test retest reliability

Answer 8

give test twice to same people and correlate scores

appropriate on measures assumed to be stable within a person ie intelligence -NOT WHEN POSSIBLE TO CHANGE IE MOOD

Question 9

what is parallel forms reliability

Answer 9

reliability checked by designers of a test when developing alternative version of same test - make sure all versions present similar scores from the same person
- avoid memory/practice effects in repeated measures designs
if high correlation then likely to be equivalent in measure

Question 10

what is inter item reliability

Answer 10

diff items used in test to measure the same construct - average scores to give overall idea of whole contruct ie a personality trait
cronbachs alpha - indicate internal consistency by providing average measure of all ways of splitting items

Question 11

how do you know if something has high reliability

Answer 11

smaller diff between measured and true scores (reduction in random error)

Question 12

cronbachs alpha

Answer 12

how well groups of items correlate with eachother
larger no items = higher alpha
min 0;7, preferably 0.8
check for each independent subscale within the study + effect if one deleted

Question 13

what is inter rater reliability

Answer 13

are the people conducting the test being reliable - PEARSONS R
training and instructinos to testers must be clear to ensure measure same beh and agree - reduce subj

can also be over time ie intervals

Question 14

measuring inter rater reliability

Answer 14

pearsons r
3+ raters can be tested by cronbachs
non para = kendalls (rank)
cohens kappa- possibility that raters actually guess on at least some variables due to uncertainty - correxts for variable of chance agreement k= p=

Question 15

reliability to check for in questionnaires

Answer 15

inter item - cronbach

Question 16

reliability to check for in rating scales

Answer 16

inter rater agreement - especially when non expert and novel scale

Question 17

reliability to check for in observations

Answer 17

inter observer/rater

check code same situations when independent

Question 18

if a study is invalid

Answer 18

it can still be reliable

Question 19

if a study is unreliable

Answer 19

it cannot be valid

Question 20

types of validity

Answer 20

face
content
predictive
concurrent
construct

Question 21

face validity

Answer 21

the items that are convincing/acceptable to users
asks appropriate qs and is taken seriously
aspect of content

Question 22

content validity

Answer 22

are the items appropriate for the intended purpose - relevant to the desired construct

Question 23

face and content

Answer 23

both to do with the kinds of items within a test

both are judged by a consulting expert and/or interested informants

Question 24

predictive validity

Answer 24

do the scores on a test correlate with what they are expected to

Question 25

concurrent validity

Answer 25

do the scored on a test correlate with alternative existing tests of a similar construct
Does the test properly reflect the theoretical nature of the psychological construct that it is intended to measure? - depends on agreement on what the theoretical nature of the construct is (e.g. intelligence).
OR Does test score correlate with other things (or differ between groups) in the way which, according to theory, it should?

Question 26

construct validity: convergent

Answer 26

does a test discriminate pos/neg with the things it theoretically should

Question 27

construct validity: discriminant

Answer 27

does the test not correlate with the things it is theoretically independent from

Question 28

campbell and fisk multi trait multi method matrix

Answer 28

test if shows both convergent and discriminant validity
test pps on possibly overlapping contructs that test claims to measure/not measure and check corr between same group of people

Question 29

lindsay et al 1994 multi trait multimethod matrix

Answer 29

anxiety and depression delf report for people with intellectual disabilities
- if svalid then convergent on anxiety and depression scores but not on anxiety/depression subscales ie social skills (disriminant)