What is probability
A numerical measure of the likelihood or chance that certain events will occur
What is a null hypothesis
A statement of no relationship. How probable is the research result if there is actually nothing going on
What do you psychologist use to assess if the result is due to chance or real affect
Psychologists use the 95% level: P equals 0.05 mins 5% possibility that result is due to chance, 95% possibility that it is a real effect
In research concerning e.g. life and death matters, probability level is 0.01
What is a type one error
Rejecting a null hypothesis that is true
What is a Type II error
Excepting a null hypothesis that is false
When can parametric tests be used
With an interval or ratio level of measurement
Be drawn from population with normal distribution
Both samples have equal variances
Why statistical tests used
To produce a calculated value
What is needed to be known to determine the significance
The significance level usually p equals 0.05
One or two tailed test
Value of N or df
