inferential statistics (statistical tests)

What are the three questions to ask yourself when choosing a statistical test?

1. Is the study looking for an association or a difference?

2. What type of participant design was used?

3. What sort of data was produced?

What is an association?

No manipulation of variables - just comparing the relationship between two variables

What is a difference?

When the IV is manipulated to measure DV

What are the types of participant designs that can be used?

Related design - repeated measures or matched pairs

Unrelated design - independent measures

ONLY USED WHEN THERE IS A DIFFERENCE

What are the types of data that can be used?

Nominal

Ordinal

Interval

What is nominal data?

The data is in categories and you can count the frequency

What is ordinal data?

The data is placed in order or ranked

What is interval data?

The data is based on numerical scales in units of equal size

How do you find the critical value for a statistical test?

1. Is the hypothesis 1 or 2 tailed?

2. What is the s-value?

3. How many participants are in the study?

4. What is the significance level?

ALL OF THESE SHOULD BE GIVEN IN THE QUESTION

How do you calculate the s-value?

1. Take the score after away from the score before

2. Count the number of positive and negative numbers - disregard any 0’s

3. The lowest number is the s-value

How do you calculate whether the s-value is significant for a sign test?

p-value ≤ s-value