Chapter 4

Question 1

reliability

Answer 1

A measure is said to be reliable if the results are repeatable when behaviours are remeasured. Reliability is a direct function of measurement error

Question 2

validity

Answer 2

a test is said to be valid if it measures what it is designed to measure (assumes reliability but not vice versa)

Question 3

validity types

Answer 3

• content validity
• criterion validity
• construct validity

Question 4

face validity

Answer 4

how valid a test appears to the taker, not really a kind of validity

Question 5

content validity

Answer 5

simplest level of validity - concerns whether or not content of items on a test make sense in terms of the construct being measured

Question 6

criterion validity

Answer 6

concerns whether measure can accurate forecast of future behaviour or whether behaviour is meaningfully related to some other measurement of behaviour

Question 7

construct validity

Answer 7

concerns whether a test adequately measures some construct and connects to operational definition, establishes convergent and discriminant validities

Question 8

convergent validity

Answer 8

established by construct validity - scores on a test that measures some construct should relate to scores on another test measuring the same construct

Question 9

discriminant validity

Answer 9

established by construct validity - scores on a test that measures some construct should not relate to scores on another test measuring a different construct

Question 10

nominal scale

Answer 10

functional unity

Question 11

ordinal scale

Answer 11

functional unity, order

Question 12

interval scale

Answer 12

functional unity, order, equal intervals

Question 13

ratio scale

Answer 13

functional unity, order, equal intervals, absolute 0

Question 14

descriptive statistics

Answer 14

summarize data collected from sample population

Question 15

inferential statistics

Answer 15

allow you to draw conclusions about data that can be applied to the wider population

Question 16

mean

Answer 16

measure of central tendency - average (with standard deviation)

Question 17

median

Answer 17

measure of central tendency - middle number in data arranged sequentially (with IQR)

Question 18

mode

Answer 18

measure of central tendency - number that appears most frequently (with range)

Question 19

outliers

Answer 19

scores that fall far outside the mean

Question 20

range

Answer 20

measure of variability - highest - lowest + 1

Question 21

IQR

Answer 21

data that falls in the middle 50% of the set of scores (arranged sequentially)

Question 22

standard deviation

Answer 22

estimate of avg amount by which scores in the sample deviate from the mean (square root of EX^2 over (N-1) where x^2 = difference score between X bar and X score) 68% of scores fall between -1 and 1 standard deviation, 98% fall between -2 and +2

Question 23

variance

Answer 23

SD^2

Question 24

histogram

Answer 24

Y=frequency, X=score

Question 25

frequency distribution

Answer 25

tally of # of times each score appears

Question 26

alpha level

Answer 26

probability of obtaining experiment results if Ho is true (linked to prob of type 1 error)

Question 27

Type 1 error

Answer 27

Reject Ho when it is true

Question 28

Type 2 error

Answer 28

Retain Ho when it is false

Question 29

systematic variance

Answer 29

result of an IDable factor, either variable of interest or some factor you have failed to control adequately

Question 30

error variance

Answer 30

nonsystematic variability due to individual differences and random, unpredictable effects during the study

Question 31

effect size

Answer 31

estimate of magnitude of difference among sets of scores taking into account variability (can combine eta scores of individual studies into a meta analysis of related studies)

Question 32

confidence interval

Answer 32

range of values expected to contain a population value with a certain degree of confidence C= X bar +/- t (standard error of the mean, calculated by SD/root of N)

Question 33

power

Answer 33

ability of a test to reject Ho; affected by alpha, effect size, variance, and size of N (too small, can’t see effect; too large, magnifies)

Question 34

historically psychology’s examples have been:

Answer 34

Western
Educated
Industrialized
Rich
Democratic

Question 35

Varieties of psychological measurement

Answer 35

• self report
• behavioural
• physiological

Question 36

file drawer problem

Answer 36

bias against publishing statistically non-significant findings