28. Probability And Significance AO1 Flashcards
What is done if the if the test is not significant?
The null hypothesis is accepted
What is a null hypothesis?
States there is no difference or correlation between conditions
What does the statistical test determine
Which hypothesis (null or alternative) is true and which to accept/reject
What is probability?
A measure of the likelihood that a particular event will occur
What are the nothing of in psychology?
There are no certainties but there is a significance level
What is a significance level?
The point at which the null is accepted or rejected
What is the usual level of significance?
0.05 or 5%
What does a significance of 0.05 mean?
Probability that the observed effect occurred by chance is equal or less than 5%
How is statistical significance tested?
Comparing calculated value with critical value in a table of critical values based on probabilities
What are the three criteria for finding the correct critical value?
- Hypothesis one-tailed (directional) or two-tailed (non- directional)
- Number (N) of participants or degrees of freedom (df)
- Level of significance (p value)
What is a type I error?
Null hypothesis rejected and alternative wrongly accepted
What is a type II error?
Alternative rejected and null wrongly accepted
What kind of error is a type I error?
Optimistic error or false positive as significant difference/correlation was found when it didn’t exist
What kind of error is a type II error?
Pessimistic error or false negative
What makes a type I error more likely?
If the significance level is too lenient (too high)
