Chapter Nine Flashcards
A fundamental assumption of chi square tests is that no more than ____% of cells can have an expected frequency of less than ____
25% ; 5
Although in a one variable chi square test each participant cannot be in more than one group, in a 2 x 2 chi square test this rule does not apply. True or false
False
Data for a chi square test should be assumed to have no less than one participant per cell. If there is less than one participant per cell, it is sometimes useful to combine cells together into one category. True or false?
True
For a 2x2 chi square test, which of the following equations would be used to calculate the degrees of freedom?
(r-1) x (c-1)
How do we calculate the degrees of freedom for a goodness of fit test?
Number of categories -1
If the assumption of 25% of cells w less than 5 isn’t met in a 2x2 chi square test what should you conduct
A fishers exact probability test
One serious complication associated with the analysis of more than theee levels (e.g. 4x5) is:
It can be different to interpret accurately all of the relationships within a large contingency table
A study was conducted where the times that students submitted their essays was analysed. In this number of early, later and on time students were counted. The number of students who planned their time was also counted, leading to two levels of time planning out or not. How would this be described
3x2
Should you have use a one or two tailed hypothesis for a chi square analysis
It doesn’t matter
What are the four steps of chi square tests
Take the expected frequencies away from the observed frequencies
Square all the numbers
Divided the numbers by a measure of variance (expected frequencies)
Sum all the numbers
Using a goodness of fit test we can assess whether a set of obtained frequencies differ from a set of _______ frequencies
Expected
What does the fishers exact probability test show
It shows the probability of obtaining the chi square value when the null is assumed to be true
What is Cramer’s V used for
Cramer’s V is a measure of effect used for tests of association
What sort of data is appropriate for chi square tests
Frequency counts
When reporting your results, what elements should you include from the SPSS output
The pearsons X2, degrees of freedom and the probability level
Which statement is false of chi square testing
Chi square can be applied to continuous variables; it just means that a larger contingency table is needed
Which of the following hypotheses would be suited for testing by a one variable chi square test
It is hypothesised that in terms of car colour, more individuals choose a red car than a green, black or silver car
You are conducting a one variable chi square test to test the hypothesis that there are equal numbers of vegetarians etc what would the expected frequencies be in each cell
79.67
You conduct a study exploring whether or not students planned their time and whether or not they submitted their assignment on time. Your SPSS output shows a value of Cramer’s V of 0.42. How would you interpret this
18% of the variation in frequency counts of essay submission timing (on time or late) can be explained by time planning
