Module 10: Correlation and Regression

Question 1

Correlation test use

Answer 1

-evaluate whether there is an association between 2 numerical variables
-whether one variable trends up or down as the other changes

Question 2

Correlation coefficient values

Answer 2

-0 means no association
-1 means positive association
- -1 means negative association

Question 3

Correlation test null and alternative

Answer 3

-Ho: p = 0
-Ha: p =/ 0

Question 4

Correlation test null distribution shape

Answer 4

-t distribution

Question 5

Correlation test t score calculation

Answer 5

-To: r - p / SE
-SE: square root of 1 - r^2 / df

Question 6

Correlation test degrees of freedom

Answer 6

-n - 2
-n is for sample size

Question 7

Correlation test reporting

Answer 7

-symbol for test (r)
-degrees of freedom
-observed correlational value (2 decimal places)
-p value (5 decimal places)

Question 8

Linear regression test use

Answer 8

-evaluate whether changes in one numerical variable can predict changes in a second numerical variable

Question 9

Linear equation

Answer 9

• y = mx + b
  -y is for response variable
  -x is for predictor variable
  -m is for slope
  -b is for intercept

Question 10

Statistical model for linear regression

Answer 10

-systematic component: the slope line
-random component: standard error of each data point, mean changes but standard deviation does not
-link component: states that mean of normal distribution is the same as predicted variable from linear equation

Question 11

Linear regression intercept null and alternative

Answer 11

• Ho: a = ba
• Ha: a =/ Ba
  -a is for intercept
  -Ba is for reference value

Question 12

Linear regression slope null and alternative

Answer 12

• Ho: b = Bb
  -Ha: b =/ Bb
  -b is for slope
  -Bb is for reference value

Question 13

Linear regression null distribution shape

Answer 13

-t distribution

Question 14

T score calculation for intercept

Answer 14

-T0: a - Ba / SE

Question 15

T score calculation for slope

Answer 15

-To: b - Bb / SE

Question 16

Linear regression degrees of freedom

Answer 16

• n - 2

Question 17

Linear regression reporting

Answer 17

-symbol for test (a or b)
-observed parameter values
-observed t score
-degrees of freedom
p value