psychometrics

Question 1

what is psychometrics

Answer 1

branch of psychology concerned with the scientific measurement of individual differences

Question 2

how are psychometrics used in clinical paychology

Answer 2

• interviews to assess patients
• usually lots of tests rather than a single test
• diagnosis of mental illnesses, learning disabilities

Question 3

how are psychometrics used in forensic psychology

Answer 3

*used to inform legal decision making
deciding whether a defendant is legally competent
*levels of intelligence vis IQ testing

Question 4

how are psychometrics used in educational and occupational psychology

Answer 4

*measurement of academic abilities

Question 5

reliability

Answer 5

the consistency of a measure across time and circumstances

Question 6

validity

Answer 6

does the measure asses what it claims to?

Question 7

internal reliability

Answer 7

how well all of the items in a scale measure the construct

Question 8

split half reliability (internal reliability)

Answer 8

pearsons r for two halves of the scale

Question 9

odd-even reliability (internal reliability)

Answer 9

correlate odd and even sets of scores

Question 10

alpha reliability - Cronbachs alpha (internal reliability)

Answer 10

average of very possible half correlated with average of every other possible half (use SPSS)

Question 11

test-retest reliability

Answer 11

correlate scores at T1 with T2

Question 12

why is alternate form reliability used

Answer 12

to cancel out memory effects

Question 13

face validity

Answer 13

informal assessment of whether the content of a scale appears to measure what it sets out to

Question 14

content validity

Answer 14

systematic examination of the extent to which test covers a representative sample of the domain to be measured

Question 15

concurrent validity

Answer 15

does the scale correlate well with other measures of the same concept taken at the same time

Question 16

predictive validity

Answer 16

extent to which a measure predicts something that it theoretically should be able to predict

Question 17

conceptual variable (scale construct)

Answer 17

the idea that we are attempting to capture - hypothetical constructs that cant be directly observed
*eg quality of lifr

Question 18

operational variable (scale construct)

Answer 18

the specific way in which the variable of interest is measured in the study

Question 19

nominal level (level of scale)

Answer 19

the variable takes response values with no intrinsic ranking eg gender

Question 20

ordinal level (level of scale)

Answer 20

the variable takes response values with some intrinsic ranking eg life satisfaction scale (satisfied, somewhat satisfied)

Question 21

scale level (level of scale)

Answer 21

the variable takes ranked response values with constant differences eg life satisfaction scale (ranging from 1-10)