inferential statistics for ordinal data

Question 1

what measures of central tendency can be used for ordinal data

Answer 1

median and mode

Question 2

for the mann whitney u test what types of hypothesis are used

Answer 2

null and alternative

Question 3

what do we do will the data in a mann whitney u test

Answer 3

add all the data from both groups and order it from smallest to largest (assigning a RANK)

then split it back up into the 2 groups and sum up the value of the ranks for both groups, this will give the sum of the ranks

The data is ranked all together, then separated into the original groups. Each group of data has its own sum of the ranks.

Question 4

the p value tells us the probability of…

Answer 4

observing our results (by chance) if the null hypothesis is correct.

Question 5

As the U-value gets smaller, the p value gets

Answer 5

smaller

Question 6

The smaller the U-value, the ….. the probability of observing our results if the ….. hypothesis is correct

Answer 6

smaller the probability of observing our results, if the null hypothesis is correct.

Question 7

The smaller the U-value, the …… the probability of observing our results if the …. hypothesis is incorrect

Answer 7

bigger the probability of observing our results, if the null hypothesis is incorrect.

Question 8

the smaller the u value the ….. likely it is that the null hypothesis is correct, and the more likely we are to ……. our null hypothesis

Answer 8

The smaller the U-value, the less likely it is that the null hypothesis is correct, and the more likely we are to reject our null hypothesis.

Question 9

The bigger the difference between the sum of the ranks of the two groups the …… the u value and p value

Answer 9

the smaller the u value and p value

Question 10

A table gives the critical U-values at the 5% significance level for a one-tailed test. For a two-tailed test, at what significance level does the same table give the critical U-values?

Answer 10

10%

Question 11

if two people are joint in 8th place ranking which rank do we give them and why (more than one person ranked in the same place gives them a decimal ranking

Answer 11

(8+9) divided by 2= 8.5

Question 12

for a table of critical values in the MWU test is there degrees of freedom

Answer 12

no there is just an N value (sample size for each group it doesnt matter which one is which is group 1 and which is group 2

Question 13

what does the critical u value indicate

Answer 13

the critical u value gives you the value you need to observe in order to reject the null hypothesis

Question 14

In order to reject the null hypothesis our observed U-value must be…

Answer 14

Less than or equal to the critical U-value.