Correlational Investigations Flashcards
What is the difference between the purpose of correlations and experiments?
Experiments look for a difference between two conditions. A correlation is a way of measuring the relationship between two variables to see if a trend or pattern exists between them.
What is the difference between terminology used for correlations and experiments?
Correlations assess the relationship between variables, but there is no independent variables involved as nothing is manipulated.
What are the strengths of correlational analysis?
• can be used where it would be unethical or impractical to manipulate variables.
• often used as ‘preliminary research’ to identify possible causal factors.
What are the weaknesses of correlational analysis?
• can’t establish clear cause and effect due to lack of control over extraneous variables.
• can only be used if data sets from both variables are over a range of numbers and not in categories.
What are the similarities between hypotheses for experiments and correlations?
They both have a null hypothesis and an alternative hypothesis (directional or non-directional).
What are the differences between the hypotheses for experiments and correlations?
Correlation hypotheses don’t have ‘difference’ or ‘IVs and DVs’. Instead there are two co-variables and we are looking for the relationship/correlation between them.
Give an example of a null hypothesis.
There will be no relationship between … and …
Give an example of an alternative hypothesis
There will be a (positive/negative) relationship between … and …
How do you visually represent correlation?
Using a scatter graph.
How do you plot correlation on a scatter graph?
Dots are plotted on the scatter graph to represent each pair of scores - you are plotting the two variables against each other, you are not plotting participant numbers.
What is a positive correlation?
As one variable increases, so does the other.
What is a negative correlation?
As one variable increases, the other decreases.
What does it mean when there is no correlation?
There is no relationship between the two variables.
