Chapter 8 Correlation Flashcards Preview

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Flashcards in Chapter 8 Correlation Deck (24):
1

Strength Magnitude

A characteristic of a correlation with a focus on how strongly 2 variables are related.

2

Causation

The concept that variations in one variable CAUSES variation in another variable

3

Correlation Coefficient

A statistic that reveals the strength and direction of the relationship b/w 2 variables

4

Coefficient of Determination

A stat found by squaring the Pearson Correlation Coefficient that reveals the % of variance explained in each of the 2 correlated variables by the other variable

5

Shared Variance

The concept of 2 variables overlapping such that some of the variance in each variable is shared. The stronger the correlation b/w the 2 variables the greater the amt. of shared variance b/w them.

6

Scattergram / Scatterplot

A graphical depiction of each member of a distribution score on 2 variables simultaneously

7

Positive Correlation

A characteristic of a correlation when the scores on the 2 correlated variables move in the same direction, on average.
As the scores of one variable rise, scores on the other variable rise and vice versa.

8

Perfect Positive Correlation

A correlation coefficient of r = +1.0 occurs when increases in scores of a given size on one of the variables in a correlation are associated with increased scores of a related size on a second variable in the correlation.

(e.g. for each 1 - unit increased in the score on a variable X there is a corresponding 2 - unit increase in the scores on variable Y)

9

Perfect Negative Correlation

A correlation Coefficient of r = - 1.0 occurs when the increasing scores of a given size on one of the variables in a correlation are associated with decreasing scores of related size on a second variable in the correlation.

(i.e. for each 1 - unit increase in the score on variable X there is a corresponding 2 - unit DECREASE in scores on Y variable.

10

Pearson Product - Moment Correlation Coefficient

A statistic indicating the strength and direction of the relation b/w 2 continuous variables.

11

Negative Correlation

A descriptive feature of a correlation indicating that as scores on one of the correlated variables increase scores on the other variable decrease and vice versa

12

Dichotomous Variable

A categorical, or nominal variable with 2 categories.

13

Direction

A characteristic of a correlation that describes whether 2 variables are positively or negatively related to each other.

14

Explained Variance

The % of variance in one variable that we can account for, or understand, by knowing that value of the 2 variables in the correlation.

15

Cross Products

The product of multiplying each individual scores on 2 variables

16

Curvilinear

A relationship b/w 2 variables that is positive at some values but negative at other values.

17

Covariance

The average of the cross products of a distribution.

18

Truncated Range

When the response of a variable are clustered near the top or bottom of the possible range of scores, thereby limiting the range of scores and possibly limiting the strength of the correlation.

19

Z Score

Standard Score

20

r

The Sample Pearson Correlation Coefficient

21

p

Rho, the population correlation coefficient

22

Sr

The standard error of the correlation coefficient

23

r2

The Coefficient of Determination

24

Degrees of Freedom (df)

Min. amt of data needed to calculate a statistic. More practically, it is the number(s), used to approximate the number of observations in the data set for the purpose of determining statistical significance.