Chi Test

Question 1

what does chi-square analysis consist of?

Answer 1

test how well the observed frequencies conform to the expected frequencies.

measures degree of fit between the observed and expected frequencies.

Question 2

what is the symbol for chi square?

Answer 2

χ2

Question 3

what does chi-square analyse?

Answer 3

in chi-square analysis, we analyse the frequencies that exist within categories

Question 4

what does chi-square compare?

Answer 4

comparing observed (or obtained) frequencies with expected frequencies. The chi-square statistic expresses the discrepancy between the observed and expected frequencies.

Question 5

how do we calculate expected frequencies?

Answer 5

Calculating the expected frequencies can be obtained by

–Goodness of fit

-Test of independence

Question 6

describe chi test as a goodness of fit test

Answer 6

have a theory or hypothesis about how well the observed data should fit the expected data.

Question 7

Describe Ho in goodness of fit test for chi square

Answer 7

Ho: The observed data does fit the expected data –Therefore, rejecting Ho is a statement that the data are at odds with the expected data.

i.e The obtained frequencies don’t differ from the expected frequencies

Question 8

what is the df in goodness of fit test for chi-square analysis?

Answer 8

df for a goodness of fit test, is number of categories -1

Question 9

formula for chi square analysis goodness of fit

Answer 9

Question 10

what happens if we find a=0.045 df=1 thus critical chisquare value is 3.85 but obtained chi-value is 7.5?

Answer 10

reject Ho

There is a significant difference between the frequencies that we expect and the frequencies _we actually observed.
more than would be expected by chance._

This supports our research/alternative hypothesis that there is discrimination in this case based on gender.

Question 11

what happens when X²obt > X² critical value?

Answer 11

reject Ho

significant difference between the frequencies that we expect and the frequencies we actually observed. more than would be expected by chance.

Question 12

when is chi-square analysis used?

Answer 12

chi-square statistic is used to evaluate the relative frequencies of events in a population that fall into well defined categories

for each category there is an expected frequency and observed frequency

Question 13

describe chi-square as test of independence

Answer 13

test the independence of two variables on which frequency data are available.

Question 14

what is the Ho for test of independence in chi-test?

Answer 14

two variables are independent

Question 15

to reject the Ho in the test of independence is making a statement that

Answer 15

Rejecting the Ho is a statement that two factors are not independent, but related.

Question 16

Give an example of retaining Ho and rejecting Ho

Answer 16

Retaining Ho is a statement that pet ownership and gender are independent in the population i.e., that knowing someone’s gender does not tell you anything about whether they might be likely to own a pet

Rejecting Ho: pet ownership is dependent upon gender

Question 17

how to calculate df in test of independence?

Answer 17

df = (rows – 1)(columns – 1)

Question 18

what happens when the X²obt is > X²critical value from the test of independence?

Answer 18

we reject the Ho

one can conclude that pet ownership is influenced by gender; they are not independent, but related.