Correlations

Question 1

What is a correlation?

Answer 1

A mathematical technique in which a researcher investigates an association between two variables, called co-variables. Always ordinal or interval data.

Question 2

What is a positive correlation?

Answer 2

As one co-variable increases so does the other. For example, the number of people in a room and noise tend to be positively correlated.

Question 3

What is a negative correlation?

Answer 3

As one co-variable increases the other decreases. For example, the number of people in a room and amount of personal space tend to be negatively correlated.

Question 4

What is zero correlation?

Answer 4

When there is no relationship between the co-variables. For example, the association between the number of people in a room in Manchester and the total daily rainfall in Peru is likely to be zero.

Question 5

What are co-variables?

Answer 5

The variables investigated within a correlation, for example, height and weight. They are not referred to as the independent and dependent variables becuase a correlation investigates the association between the variables, rather than trying to show a cuase-and-effect relationship where one variable “depended” on the other.

Question 6

What is are curvilinear/non-linear relationships?

Answer 6

A curvilinear relationship is a type of relationship between two variables that has a pattern of correspondence or association between the two variables that change as the values of the variables change (increase or decrease).

Question 7

What are correlation coefficients?

Answer 7

A number between -1 and +1 that represents the direction and strength of a relationship between co-variables.

Question 8

Why do we use correlations and what statistical test would we use for them?

Answer 8

Correlations are used in the assessment of reliability and validity. The coefficient must be above +.8 for a study to be considered reliable and/or valid. The statistical test would be Spearman’s or Pearson’s.

Question 9

What are 5 strengths of correlations?

Answer 9

• Correlations can be done when it would be
  unethical to manipulate the variables
• Correlation can be done when it would be
  impractical to manipulate the variables
• If a correlation is not significant, you can probably
  rule out a casual (cause and effect) relationship
• If it is found to be significant, then further
  investigation (e.g. An experiment) can be justified
• Like with experiments, procedures can be
  repeated to confirm findings

Question 10

What are 3 weaknesses of correlation?

Answer 10

• People often misinterpret correlations and
  assume that a cuase and effect relationship has
  been found, but this is not possible
• Unknown variables (intervening variables) may
  explain why the co-variables being studied are
  linked
• As with experiement, they ay lack validity e.g. The
  way they measure a variable isn’t realistic or the
  sample may not be generalisable