Lesson 4

Question 1

What is the difference between a sample and a population?

Answer 1

A population is a group that have at least one common characteristic while a sample is part of a population.

Question 2

What do you assume with the null hypothesis?

Answer 2

There is no change, relationship or difference between variables of interest.

Question 3

What is the difference between two-tailed and one-tailed hypotheses? Which one do you want?

Answer 3

TT- there is no direction of difference between conditions.

OT- There is a direction/difference. What one-tailed.

Question 4

What are the 2 principles of hypothesis testing?

Answer 4

• Mutually exhaustive. (if one hypothesis is true the other must be false).
• Exhaustive (the null and alternative H describe all possible conditions).

Question 5

When do you fail to reject the null.

Answer 5

p value is greater than 0.05 or 5%.

Question 6

What do you want as a statistical conclusion and what is the danger?

Answer 6

Power- but when you try to increase statistical power you also increase Type 1 error.

Question 7

What error has more consequences in research?

Answer 7

Type 1 (false positive).