Psc 41 Midterm 2

Front 1

frequency distribution

Back 1

table with scores listed with frequency

Front 2

qualitative variable

Back 2

categorical variable for whcih each value represents a discrete category

Front 3

quantitative variable

Back 3

scores represent a change in quantity

Front 4

histogram

Back 4

vertical bars centered above scores on the x-axis touch each other to indicate that the scores on the variable represent related, increasing values

Front 5

measure of central tendency

Back 5

# that characterizes the "middleness" of an entire distribution

Front 6

standard deviation

Back 6

square root of the average squared deviation from the mean

Front 7

average deviation

Back 7

average difference between scores in a distribution and the mean of the distribution

Front 8

normal cuvrve

Back 8

bell-shaped frequency polygon representing a normal distribution

Front 9

normal distribution

Back 9

a theoretical frequency distribution that has certain special characteristics

Front 10

kurtosis

Back 10

how flat or peaked a normal distribution is

Front 11

mesokurtic

Back 11

normal curves that have peaks of medium height

Front 12

leptokurtic

Back 12

normal curves that are tall and thin

Front 13

positively skewed distribution

Back 13

distribution in which the peak is to the left, tail extends toward the right

Front 14

negatively skewed distribution

Back 14

distribution of the peak is to the right

Front 15

standard normal distribution

Back 15

normal distribution with a mean of 0 and a standard deviation of 1

Front 16

scatterplot

Back 16

represents the relationship between 2 variables

Front 17

causality

Back 17

assumption that a correlation indicates a causal relationship between the 2 variables

Front 18

directionality

Back 18

inference made w/ respect to the direction of a causal relationship between 2 variables

Front 19

pearson's r

Back 19

most comonly used correlation coefficient when both variables are measured on an interval or ratio scale

Front 20

spearman's rank-order correlation coefficient

Back 20

when one or more of the variables is measured on an ordinal (ranking) scale

Front 21

point-biserial correlation coefficient

Back 21

one of the variables is measured on a dichotomous nominal scale, and the other is measured on an interval or ratio scale

Front 22

phi coefficient

Back 22

both measured variables are dichotomous and nominal

Front 23

between-participants design

Back 23

participants are assigned to each group

Front 24

posttest-only control group design

Back 24

dependent variable is measured after the manipulation of the independent variable

Front 25

pretest/posttest control group design

Back 25

dependent variable is measured both before and after manipulation of the independent variable

Front 26

confound

Back 26

uncontrolled extraneous variable or flaw in an experiment

Front 27

internal validity

Back 27

results of an experiment can be attributed to the manipulation of the independent variable rather than to some confounding variable

Front 28

history effect

Back 28

threat to internal validity where an outside event that's not a art of the manipulation of the experiment could be responsible for the results

Front 29

maturation effects

Back 29

threat to IV, participants mature physically, socially, and cognitively during the study

Front 30

testing effect

Back 30

threat to IV, repeated testing may lead to better or worse performance

Front 31

regression to the mean

Back 31

threat to IV, people who did well the first time is because maybe of chance or luck, 2nd time might not be so lucky

Front 32

instrumentation effect

Back 32

measuring device is faulty

Front 33

mortality (attrition)

Back 33

threat to IV, differential dropout rates may be observed in the experimental and control groups, leading to inequality between the groups

Front 34

diffusion of treatment

Back 34

observed changes in the behaviors of participants may be due to information received from other participants in research studies

Front 35

experimenter effect

Back 35

results are biased by the experimenter's expectations

Front 36

single-blind experiment

Back 36

experimenter or participant is blind to the manipulation

Front 37

double-blind experiment

Back 37

neither the experimenter nor the participant knows the condition

Front 38

participant effect

Back 38

threat to IV, participants know they're being observed and so will behave unnaturally

Front 39

placebo group

Back 39

group of participants who think they're receiving treatment but they're not

Front 40

floor effect

Back 40

differentiate between scores at the bottom of the scale

Front 41

ceiling effect

Back 41

differentiate between scores at the top of the scale

Front 42

external validity

Back 42

results of an experiment can be generalized

Front 43

cross-sectional design

Back 43

researches study individuals of different ages at the same time

Front 44

cohort

Back 44

group of individuals born at about the same time

Front 45

cohort effect

Back 45

individuals raised at different times

Front 46

longitudinal design

Back 46

same participants are studied repatedly over time as they age

Front 47

sequential design

Back 47

combination of the cross-sectional and longitudinal designs

Hint 47

measure a few groups of people in different ages over a period of time

Front 48

single-case design

Back 48

only one participant is used

Front 49

small-n design

Back 49

a few participants are studied

Front 50

cross sectional design

Back 50

study individuals of diff. ages at the same time