inferential tests

Question 1

when do you use a binomial sign test?

Answer 1

when there is a difference between the data collected in two conditions, repeated measures design with nominal level data

Question 2

sign test method?

Answer 2

1. calculate the difference between the two conditions (a-b)
   a+ for positive differences
   a- for negative differences
   leave any 0 differences between conditions black and removed from total participants (N)
2. add up the number of +signs and -signs
   whichever group (+ or -) is smaller, is S

Question 3

in a sign test, the observed value of S must be _________ or ________ than the critical value to be significant

Answer 3

equal to or less than

Question 4

when do you use mann whitney U test?

Answer 4

when there is a difference between the two conditions, IMD with ordinal level data

Question 5

mann whitney U test method?

Answer 5

1. if one condition has LESS participants, call this condition A
2. rank all the scores together, as if they belonged to just one group, but record the ranks for each group separately
3. find the sum of the ranks for each condition (R1 and R2)
4. calculate U1 and U2 using the formula
5. U is the smaller of U1 and U2

Question 6

in a mann whitney U test, the observed value of U must be _________ or ________ than the critical value to be significant

Answer 6

equal to or less than

Question 7

when do you use a wilcoxon test?

Answer 7

when there is a difference between the data obtained in two conditions, RMD with ordinal level data

Question 8

wilcoxon test method?

Answer 8

1. work out the difference between the scores in the two conditions (a-b)
2. rank the differences from smallest to largest
3. ignore any + or -, and ignore any 0 (we take this from N)
4. find the sum of the ranks of the positive differences
5. find the sum of the ranks of the negative differences
6. T is the smallest of these 2 values

Question 9

in a wilcoxon test, the observed value of T must be _________ or ________ than the critical value to be significant

Answer 9

equal to or less than

Question 10

when do you use a chi squared test?

Answer 10

when there is a difference between the data collected, data is nominal

Question 11

chi squared method?

Answer 11

1. calculate expected frequencies (if they are not already done for you) by doing E = R x C / T
   E = row total x column total / grand total
2. step by step table
   - cell ( a b c d)
   - observed frequencies from contingency tables
   - expected frequencies
   - O - E
   - (O - E) squared
   - (O - E) squared / E
3. degrees of freedom (R-1) x (C-1)

Question 12

in a chi squared, the observed value must be _________ or ________ than the critical value to be significant

Answer 12

equal to or greater than (rule of R)

Question 13

when do you use spearman’s rho?

Answer 13

when there is a correlation and ordinal level data

Question 14

spearman’s rho method?

Answer 14

1. rank the values of the first variable, then rank the values of the second co-variable
2. find the difference between the ranks
3. square the differences of the ranks
4. add up the square of the differences
5. insert this into the equation for rs

Question 15

in a spearman’s rho, the observed value of rs must be _________ or ________ than the critical value to be significant

Answer 15

equal to or greater than