Biostats Correlation

Question 1

is primarily concerned with finding out whether a relationship exists and with determining its _________ and _________

Answer 1

Correlation, magnitude,
direction.

Question 2

When two variables vary together, such as loneliness and depression, they are said to be

Answer 2

correlated

Question 3

Typically, in a correlational study, no variables are manipulated as in an experiment the researcher measures naturally occurring events, behaviors, or personality characteristics and then determines if the measured scores ______

Answer 3

covary

Question 4

The simplest correlational study involves obtaining a pair of observations or measures on _______________________ from a number of individuals.

Answer 4

two different variables

Question 5

When one variable moves a certain direction, the other tends to move in the same of opposite direction

Answer 5

COVARIANCE

Question 6

Is one of a family of statistical measures used to analyse the linear relationship between two variables.

Answer 6

Covariance

Question 7

Covariance provides the _________ (positive, negative, near zero) of the linear relationship between two variables

Answer 7

DIRECTION

Question 8

Provides DIRECTION and STRENGTH

Answer 8

Correlation

Question 9

result has no upper or lower bound and its size is dependent on the scale of the variables

Answer 9

Covariance

Question 10

__________ is not standardized
While ___________ is standardized (think z-score)

Answer 10

Covariance, Correlation

Question 11

To overcome this, standardised covariance is used which is
known as

Answer 11

Pearson’s correlation coefficient ( “r”)

Question 12

A __________ indicates that there is no association between the
two variables

Answer 12

value of 0

Question 13

A ____________________ indicates a positive association; that is, as the value of one variable increases, so does the value of
the other variable.

Answer 13

value greater than 0

Question 14

A _________________ indicates a negative association; that is, as the value of one variable increases, the value of the other
variable decreases (inverse correlation)

Answer 14

value less than 0

Question 15

The stronger the association of the two variables, the closer the ____________________________________, will be to either +1 or -1 depending on whether the relationship is positive or negative,
respectively

Answer 15

Pearson correlation coefficient, r

Question 16

Achieving a value of +1 or -1 means that all your data points are included on the line of ________ – there are no data points
that show any variation away from this line

Answer 16

best fit

Question 17

Values for r between
_________ (for example,
r = 0.8 or -0.4) indicate
that there is variation
around the line of best
fit.

Answer 17

+1 and -1

Question 18

The closer the value of
r to _ the greater the
variation around the
line of best fit.

Answer 18

0

Question 19

Correlation is only applicable to

Answer 19

LINEAR relationships

Question 20

___________ is NOT causation

Answer 20

Correlation

Question 21

____________________ does not necessarily mean the correlation is statistically significant; related to sample size.

Answer 21

Correlation strength

Question 22

Employed with interval or ratio scaled variables

Answer 22

Pearson product moment correlation coefficient ( r )

Question 23

Employed with ordered or
ranked data.

Answer 23

Spearman rank order correlation coefficient ( r rho )