Inferential statistical tests Flashcards
What are inferential statistics?
They involve mathematical procedures which allow psychologists to make inferences about the data that’s been collected
How can inferential statistics be used?
These might be used to estimate the likelihood that the data collected has occurred by chance. They could also be used to draw conclusions about a larger population from which the samples were collected
What are the 3 factors involved in selecting an inferential statistical test?
- Whether a researcher is looking for a difference or a correlation
- If its a difference, what experimental design is being used (related or unrelated)
- The level of measurement (nominal, ordinal, interval)
What are the related experimental designs?
Repeated measures, matched pairs
What is the unrelated experimental design?
Independent groups
What are the 3 levels of measurement?
Nominal, interval, ordinal
What is nominal data?
Data represented in the form of categories - one item can only appear in one of the categories
Why is nominal data limited?
It is the lowest level of data because it only gives us a limited amount of information on the variable being measured.
What measure of central tendency would you use to represent nominal data?
Mode
What is ordinal data?
Data that is ordered n some way and involves ranking the data from highest to lowest. It does not have equal intervals between each unit UNSAFE SCALE (eg someone doesn’t enjoy something twice as much if they rate it 6 and someone else rates it 3)
Why is ordinal data limited?
It lack precision because it is based on subjective opinion
What measure of central tendency would you use to represent ordinal data?
The median
What is interval data?
Data based on numerical scales that include units of equal size
What are the advantages of interval data?
The units of measurement are precise and object
What measure of central tendency would you use to represent interval data?
The mean
