L8 - Correlations

Question 1

Correlations

Answer 1

• technique for analysing the strength of the relationship between two quantitative variables, known as co-variables.
• The data for a correlation is usually obtained from a non-experimental source, such as a survey.

Question 2

Types of correlations

Answer 2

• A positive correlation - as one variable increases the other variable increases as well
• A negative correlation - as one variable increases the other variable decreases
• No correlation - There is no relationships between the two variables at all

Question 3

Correlation coefficient

Answer 3

• The strength of a correlation can be between -1 and 1.
• Zero means that there is no correlation
• -1 means that there is a strong negative correlation
• +1 means that there is a strong positive correlation.
• The strength of the correlation is known as the correlation coefficient.

Question 4

Advantages of correlations

Answer 4

• This technique does allow psychologists to establish the strength of the relationship between two variables and measure it precisely
• This technique also allows the researcher to make predictions about one variable based on what is known about the other variable.
• Correlations permits researchers to investigate factors that could not be manipulated experimentally for ethical or practical reasons.

Question 5

Disadvantages of correlations

Answer 5

• Correlational analysis cannot demonstrate cause and effect; we cannot tell which variable influences the other.
• Even if there is a correlation between two variables it may be the case that the variables are not actually related but that there is a third unknown variable which influences both (confounding variable)
• Correlations can only measure linear relationships and does not detect curvilinear relationships. This is when there is a positive relationship up to a certain point but after that the relationship becomes negative or vice versa.