correlations Flashcards
(26 cards)
What is a correlation?
A mathematical technique in which a researcher investigates an association between two variables, called co-variables.
What are co-variables?
The variables investigated within a correlation, such as height and weight; not referred to as independent and dependent variables.
What is a positive correlation?
As one co-variable increases, so does the other (e.g., more people in a room, more noise).
What is a negative correlation?
As one co-variable increases, the other decreases (e.g., more people in a room, less personal space).
What is zero correlation?
When there is no relationship between the co-variables.
What does a correlation coefficient represent?
A number between -1 and +1 that shows the direction and strength of a relationship between co-variables.
What does a correlation coefficient of +1 indicate?
A perfect positive correlation.
What does a correlation coefficient of -1 indicate?
A perfect negative correlation.
What does a correlation coefficient of 0 indicate?
Zero correlation; no relationship between the variables.
What is a scattergram?
A type of graph where each point represents the values of two variables, used to display correlations.
How are correlations different from experiments?
In experiments, the researcher manipulates the independent variable to observe changes in the dependent variable; in correlations, no variables are manipulated.
What is an intervening variable (third variable problem)?
A variable that may be causing the observed relationship between two co-variables.
Give an example of a positive correlation.
More caffeine consumed is associated with higher anxiety levels.
Give an example of a negative correlation.
More caffeine consumed is associated with less sleep.
What is secondary data?
Data collected by others, such as government statistics, which can be used in correlational research.
List one strength of correlations.
They are a useful preliminary tool for research, providing a precise and quantifiable measure of how two variables are related.
List another strength of correlations.
Correlations are quick and economical to carry out, requiring no controlled environment or manipulation of variables.
List one limitation of correlations.
Correlations cannot demonstrate cause and effect between variables.
List another limitation of correlations.
Correlations may be affected by intervening variables, making it unclear which variable is causing the other to change.
What does it mean if a correlation is statistically significant?
It means the observed correlation is unlikely to be due to chance, depending on the size of the data set.
What is the range of possible values for a correlation coefficient?
Between -1 and +1.
What does a correlation coefficient close to +1 or -1 mean?
A strong relationship between the co-variables.
What does a correlation coefficient close to 0 mean?
A weak relationship between the co-variables.
Why are correlations often used before experiments?
They help identify possible patterns and relationships worth investigating further with experimental methods.
