Correlation

Question 1

Define correlation

Answer 1

A type of non-experimental research where researchers try to determine the relationship between two variables, with little or no efforts to control extraneous variables

Question 2

Correlation does not imply…

Answer 2

Causation

Question 3

What two characteristics can we show with correlation

Answer 3

Direction and strength of the relationship

Question 4

Positive correlation..

Answer 4

Two variables tend to move in the same direction

Question 5

Negative correlation …

Answer 5

Two variables tend to move in opposite directions

Question 6

What is the Covariance? what does it find?

Answer 6

A measure of how the two variables change together

Question 7

What are the three steps to find the Covariance?

Answer 7

1. For each participant subtract their value from the mean, for both variables, and multiply them together, giving one value for each participant
2. Sum all the values created in step 1
3. divided by number of observations - 1 (n-1)

Question 8

What does Covariance number mean?

Answer 8

If the number is positive, so it the relationship

Question 9

What are the problems with covariance?

Answer 9

• The value of covariance can be large because of the units of measurement of the variables are large.
• It is not necessarily that there is a strong relationship between the variables

Question 10

What can we use instead of covariance?

Answer 10

Correlation coefficient

Question 11

How do we find correlation coefficient?

Answer 11

Divide the covariance by the product of the standard deviations of both variables

Question 12

How do we know strength and direction using correlation coefficient

Answer 12

direction = positive means positive, negative means negative
strength = closer to 1 on each end shows strength, closer to 1 (or -1) stronger it is

Question 13

What is considered strong and weak

Answer 13

1 = perfect
0.9, 0.8, 0.7 = strong
o.6, 0.5, 0.4 = moderate
0.3, 0.2, 0.1 = weak
0 = zero

Question 14

What does a directional hypothesis state in correlation

Answer 14

direction

Question 15

What does a non-directional hypothesis state in correlation

Answer 15

That there is a relationship, could be either way