Chpt 12: Understanding Research Results: Description and Correlation (PSY302)

Question 1

3 basic ways to discrete your results of a study of relationships with between variables:

Answer 1

Comparing group percents
Correlating scores of participants on 2 variables
Comparing each group means.

Question 2

Def: Frequency Distribution

Answer 2

a set of scores typically from lowest to highest which indicates the number of times each score was obtained.

Question 3

Def: Frequency polygons

Answer 3

uses a line to represent the frequencies of scores.

Question 4

Def: Descriptive stats

Answer 4

precise statements of data taken from statistical math.

Question 5

Def: Central tendency

Answer 5

a way to value the central score of each set.

Question 6

Def: Variability

Answer 6

the amount of spread in a distribution of scores.

Question 7

Def: Standard deviation

Answer 7

the average deviation of scores taken from the mean.

Question 8

Def: Variance

Answer 8

the square of the SD

Question 9

Def: range

Answer 9

Range: the diff between the highest score and the lowest.

Question 10

_____ graphs are used when the values on the x axis are __________ categories.

Answer 10

Bar, nominal

Question 11

_____ graphs are used when the values on the x axis are __________.

Answer 11

Line, numeric

Question 12

Choosing the scale for a bar graph allows a common __________ that is sometimes used by scientists and often used by advertisers.

Answer 12

manipulation

Question 13

Def: Correlation coefficient

Answer 13

a stat that describes how strongly variables are related to one another.

Question 14

Def: Pearson product moment correlation coefficient

Answer 14

used when both variables have interval or ratio scale properties; called the Pearson r.
Provides info abt both the strength & the direction of the relationship.
Values can range from 0 to 1.00.
Results can be described visually using a scatter plot where each pair of scores is shown as a single point on a diagram.

Question 15

If the range of possible value is __________, the magnitude of the correlation coefficient is _________.

Answer 15

restricted, reduced

Question 16

Def: Restriction of range

Answer 16

an issue when scores on a variable are limited to a small subset of their possible values, making it more difficult to identify relationships for the variable to other variables of interest.

Question 17

The Pearson product r is designed to detect only _____ relationships.

Answer 17

linear

Question 18

If the relationship is curvilinear, the correlation coefficient will ____ indicate the existence of a relationship.

Answer 18

not

Question 19

Def: Effect size

Answer 19

Effect size: the strength of association between variables.

Question 20

The Pearson r correlation coefficient is one indicator of effect size; it indicates the strength of the linear association between 2 variables.
Small effects are near_______
Medium moderate effects are near ______
Large effects are above r = 50
Squared value of the coefficient r squared transforms the value of r to a ___________.

Answer 20

r=10, r = 30, percentage

Question 21

Reporting effect size provides a scale of ______ that is __________ across all types of studies.

Answer 21

values, consistent

Question 22

Def: Regression equations

Answer 22

Regression equations: calcs used to predict a person’s score on one variable when that person’s score on another variable is already known.
Y=a+bX where Y is the score we wish to predict, X is the score that is known, a is a constant, and b is the adjustment factor

Question 23

To predict a future behavior (criterion variable) on the basis of one’s score on some other variable. It’s necessary to demonstrate that there is a reasonably _______ correlation between the 2.

Answer 23

high

Question 24

Def: Multiple regression

Answer 24

Multiple regression: used to analyze the relationship between a criterion variable & more than one predictor variable.

Question 25

Def: Multiple correlation

Answer 25

the correlation between a combined set of 2(+) predictor variables & a single criterion variable.
Symbolized as R

Question 26

In research, a mediating variable is hypothesized to be intervening between variable ___________

Answer 26

X and Y

Question 27

In a mediation model, the independent or predictor variable affects a ________ variable. The mediating variable then affects the dependent or ________ variable.

Answer 27

mediating, criterion

Question 28

In research, a moderating variable changes or ______ the relationship between variable X and Y

Answer 28

limits

Question 29

The 2 terms, moderation and interaction, developed from diff research traditions, but they mean essentially the ___________ when you interpret research findings.

Answer 29

same thing

Question 30

When experimental research is properly designed, there’s no ___________ issue bc all extraneous variables are controlled, either by keeping the variable constant or by using ____________

Answer 30

3rd variable, randomization

Question 31

Multiple _______ can be used to statistically control l for the effects of the 3rd variables.

Answer 31

regression

Question 32

Def: Structural equation modeling (SEM)

Answer 32

Structural equation modeling (SEM): statistical techniques to evaluate a proposed set of relationships among variables.
After data has been collected, statistical methods can be applied to examine how closely the proposed model actually fits the obtained data

Question 33

Researchers typically present path diagrams to visually represent the models being _____.
These show the theoretical ________ paths among the variables.

Answer 33

tested, causal