statistical testing: the sign test

Question 1

what is statistical testing ?

Answer 1

a way of determining whether the hypothesis should be accepted or rejected

Question 2

what is a sign test ?

Answer 2

used to analyse a difference in scores between related items

Question 3

what are the three things you need to conduct to do a sign test ?

Answer 3

You are looking to see whether the difference between two sets of data is significant or not.
2. The data gathered is nominal (frequency data - e.g. how many people said yes or no)
3. It was a repeated measures or matched pairs design.

Question 4

What is a repeated measures design?

Answer 4

The same participants are used in both conditions

Question 5

What does the observed value need to be to be significant?

Answer 5

The sign test requires the observed value to be equal to or less than the critical value.

Question 6

State if the hypothesis is one tailed or a two tailed test.

Answer 6

Directional hypothesis - one tailed test.
Non-directional - two tailed test.

Question 7

How to record the data and work out the sign?

Answer 7

Put each pair of data in a table and add a + or - depending on the difference between the two scores

Question 8

What should you do if the difference is equal in the results table?

Answer 8

Ignore it and minus the same differences from the N value and use the new number when finding the significance.

Question 9

How to find the calculated value (S)?

Answer 9

To calculate S you add up the number of + and add up the number of - and select the smaller value.

Question 10

How to find the critical value of S ?

Answer 10

Find, N = total number of scores
Then work out if its a one tailed or two tailed test.

Question 11

Is the result significant ?

Answer 11

If the calculated value is equal to or less than the critical value the result is significant.