Correlation Flashcards
What is correlation
Correlation looks for a relationship between 2 variables. It doesn’t say that one thing causes another just that they happen in accordance with another
What must the data be in correlation study
It must be quantitative data and must be at least ordinal data
Why must the data be all least ordinal
It allows us to draw a scatter graph
What words must you NOT use when describing correlation
Difference, cause and effect, IV ,DV, effect, conditions, between
How do you write a two tailed correlation hypothesis
There will be a significant relationship between the “number of hours sleep individuals get a week”and their “happiness on a scale of one to ten ( 10=very happy and 1= very unhappy )”.
How do you write a one tailed correlation hypothesis
There will be a significant positive correlation between the “number of hours sleep individuals get a week”and their “happiness on a scale of one to ten ( 10=very happy and 1= very unhappy )”.
How do you write a null correlation hypothesis
There will be no significant relationship between the “number of hours sleep individuals get a week”and their “happiness on a scale of one to ten ( 10=very happy and 1= very unhappy )”. Any relationship found will be due to chance.
What is positive correlation
A relationship between two variables whereas one increases the other increases
What is negative correlation
A relationship between two variables where as one increases the other decreases.
What is no correlation
When there is said to be no relationship and the two variables are uncorrelated.
What do correlation coefficient tell us
The strength of the relationship between two variables but they DON’T tell us the cause and effect.
What does a correlation co-efficient of -1, -0.7, 0, 0.4 and 1 show us
-1= perfect negative correlation
-0.7 = strong negative correlation
0 = no correlation
0.4 = weak positive correlation
1= perfect positive correlation
What are the strengths of a correlation study
+ we can identify relationships between variables without having to manipulate behaviours so it can be used in situations where experimentation would be otherwise unethical or impossible
+ correlations are often used as a good starting point and can used to suggest ideas for future experimental research in order to determine a cause and effect relationship ( may create a hypothesis for future experimentation)
What are the weaknesses of a correlation study
- cause and effect can’t be established, correlation can only show a relationship between variables so we would need further research to establish a cause and effect.
- other unknown variables may have caused the link between the co-variables being measured. Therefore correlation lacks validity.
What statistical test is used for a correlation study
Spearman’s rho
