Correlations Flashcards
what is a correlation?
- the measurement of the extent to which pairs of values on two variables tend to change together
- on statistical terms
- can be positive or negative
what are co-variables?
- indicate two or more quantities being measured in a correlation by the researcher that may or may not vary with each other.
- they can be measured directly from the researcher or gathered from secondary sources
- do not have an IV or DV
What type of graphs can correlations be plotted on?
Scattergrams
What are the 3 types of correlation?
- positive correlation
-negative correlation - no correlation
what is a co-efficient?
- States the strengths and type of agreement between the two variables
what does a co-effient of +1 show?
a perfect positive correlation
what does a co-efficient of -1 show?
a perfect negative correlation
what is a correlation co-effient?
A mathematical representation of to what degree the two results are related or link
what does a curvilinear correlation mean?
Two co-variables are increasing and then start to decrease
- still a predictable relationship
Strengths of correlations
- reliable
- objective data analysis
- lead to new research
- control for ppts variables
- investigate unethical situations
how are correlations reliable?
uses sets of questionaires
how does correlations use objective data analysis?
once data is correlated, to see a relationship you could use a stats test or plot a scatter graph
how do correlations control for ppt variables?
Collecting both sets of data from the same ppts
weaknesses of correlations
- cannot infer cause and effect
- 3rd variable could have caused the increase in the co-variable
- problems with secondary data
why can you not infer cause and effect?
- you cannot randomly allocate to certain conditions
