5. Probability

Question 1

What is a type one error? (Probability methods 2)

Answer 1

• Rejecting the null hypothesis, when it is actually true
• Too stringent
• e.g. 0.01

Question 2

What is a type two error? (Probability methods 2)

Answer 2

• Accepting the null hypothesis when it is actually false
• Too lenient
• e.g. 0.1 probability

Question 3

What is one way type two errors can be reduced and why does it work? (Probability methods 2)

Answer 3

• increase the sample size

- it more accurately reflects the population it was drawn from

Question 4

What is the relationship between alpha levels and confidence levels? (Probability methods 2)

Answer 4

Alpha levels + confidence levels = 1

Question 5

What are z-scores? (Probability methods 2)

Answer 5

one values relationship to the mean in a group of values

Question 6

What do z-scores allow us to do? (Probability methods 2)

Answer 6

• compare scores from different distributions

- compare scores from the same distributions

Question 7

What is standard error? (Probability methods 2)

Answer 7

A measurement of the statistical accuracy of an estimate