Statistical Testing, Probability + Errors

Question 1

Null hypothesis definition

Answer 1

No diff or relationship

Any diff= down to chance or other factor

Question 2

Experimental/ Alternative Hypothesis

Answer 2

IS a diff/ relationship between 2

Any diff= due to IV manip

Can be…

Directional: states direction

Non- Directional: not stating diff/ direction

Question 3

Statistical testing definition

Answer 3

Allow us to decide which hypothesis to accept or reject

= we can assess the probability of the results being due to chance

Question 4

Probability definition

Answer 4

See significance level

Accepted level in psych = 0.05 (5%)

= accepts 5% or less chance. (95% chance due to manip)

= alternative hyp accepted, null rejected if 5% or less. Opposite if more than 5%

Question 5

Type 1 Error

Answer 5

Alternative= wrongly accepted

Null wrongly rejected

Due to chance, but seen as genuine

False positive

Sig level too lenient
E.g. 10%

Prevent= significance level stricter
Yet, risks Type 2

Question 6

Type 2 Error

Answer 6

Null wrongly accepted.

Actual diff, seen as chance

False negative

Sig level too strict
E.g. 1%

Prevent= should be more lenient
Yet risks type 2