correlations

Question 1

what are correlations

Answer 1

mathematical technique used to investigate an association between 2 variables (co variables)

Question 2

how do correlations differ to experiments (2)

Answer 2

-variables are measured, not manipulated
-associations are found, not cause and effect relationships

Question 3

what are co-variables

Answer 3

variables investigated within a correlation eg. height and weight

Question 4

what is a positive correlation (3)

Answer 4

-as one variable increases, so does the other
-positive gradient
-correlation coefficient is more than 0

Question 5

what is a negative correlation (3)

Answer 5

-as one variable increases, the other decreases
-negative gradient
-correlation coefficient is less than 0

Question 6

what is a zero correlation (3)

Answer 6

-no relationship
-no line of best fit
-correlation coefficient is 0

Question 7

what is a curvilinear relationship (3)

Answer 7

-as one variable increases so does the other, up until a certain point- after that it decreases as the other variable continues to increase
-forms an inverted ‘U’ shape on graph

Question 8

3 strengths of correlations

Answer 8

-can study relationship between variables that occur naturally
-can measure things that cant be manipulated experimentally
-can suggest trends that can lead to experiments (if variables are strongly related)

Question 9

2 weaknesses of correlations

Answer 9

-correlation between 2 variables does not mean that they caused each other (cant establish cause+effect)- -not possible to say that one thing causes another
-there may be another variable connecting them- third variable