statistical testing: the sign test

Question 1

what is the sign test used for

Answer 1

to determine if difference we’ve found is significant

Question 2

what 3 things are required to use a sign test

Answer 2

1. looking for a difference (not association)
2. used repeated measures design
3. organised data into categories (nominal)

Question 3

define the null hypothesis

Answer 3

states there is no difference/association between two variables

Question 4

what is the accepted level of probability in psychology

Answer 4

0.05

Question 5

what two values are compared

Answer 5

calculated value compared with critical value to decide if result is significant (critical values table)

Question 6

what information is needed to use critical values table

Answer 6

1. significance level (generally 0.05)
2. number of participants (n value or degrees of freedom ‘df’)
3. if hypothesis is one-tailed (directional) or two-tailed (non-directional)

Question 7

what must the calculated value be compared to the critical value

Answer 7

equal to or lower than critical value to be significant