RM - Statistical tests Flashcards
What are the 2 types of statistics?
Descriptive statistics and inferential statistics.
What are inferential tests used by scientists to work out?
The probabilities of certain results so we can decide whether to accept or reject a null hypothesis.
What are the types of tests divided into?
Parametric and non-parametric tests.
Which are preferred, parametric or non-parametric tests and why?
Parametric because they are more powerful.
What is nominal data?
Discrete categories.
What is ordinal data?
Discrete categories in order.
What is interval data?
Subdivided categories.
What is ratio data?
No categories.
What is a table of critical values?
The table in which you check your results.
What type of hypothesis would you use a one-tailed test for?
A directional hypothesis.
What type of hypothesis would you use a two-tailed test for?
A non-directional hypothesis.
What is a level of significance?
% confidence in result validity (=/<0.05).
What does N stand for in stats tests?
Number of ppts.
What are degrees of freedom?
Number of values that can change (Df).
What are type-one errors?
False positive.
What are type-two errors?
False negative (nothing happened but really something did happen).
What are levels of measurement (N/O/I/R)?
Types of data.
What are the levels of measurement?
Nominal
Ordinal
Interval
Ratio
What are the criteria for parametric tests?
- The level of measurement is interval or better.
- The data are drawn from a population that has a normal distribution.
- The variances of the two samples are not significantly different.
What does the level of measurement have to be for a parametric test to be used?
It has to be interval or better.
Are the intervals between the data truly equal interval?