statistical testing : the sign test

Question 1

what three things are needed in order to use sign test ?

Answer 1

• data needs to be nominal (data organised in categories)
• we need to have used a repeated measures design
• we need to be looking for a difference not association

Question 2

one tailed test is used when …

Answer 2

hypothesis is directional

Question 3

two tailed test is used when …

Answer 3

hypothesis is non-directional

Question 4

in order for the difference to be statistically significant …

Answer 4

calculated S value need to be less than or equal to critical value

Question 5

how do you do the sign test ?

Answer 5

• calculate difference between data ( mark next to it if the sign if difference is positive, negative or equal)
• count up the signs (ignore equal sign)
• S value is the less frequent sign
• N in critical value table stand for number of ppts , N is calculated by total of pulses and minuses IGNORE =
• compare the S value to the critical value table
• calculated S value need to be less than or equal to critical value in order for the difference to be statistically significant

Question 6

if results are not significant do we accept or reject null hypothesis ?

Answer 6

we accept null hypothesis