7 Flashcards
If the observed and expected completely match, then the chi^2 should be?
0.
How to calculate expectation?
Total (n)*observed
!!!Reasons why chi^2 can never really be 0?
•Its almost impossible to have a perfectly even null distribution in a large n
•You can only have discrete numbers
The chi^2 test gives you the Critical Value in which?
The value of the test statistic where the P-value = alpha.
The right side of the chi^2 value in a one-tailed test is?
Alpha. The null hypothesis can be rejected.
Chi^2 test?
Computing chi^2 with calculated degrees of freedom.
Chi^2 with no degrees of freedom?
The actual value.
If the actual Chi^2 value > chi^2 of calculated degrees of freedom, then?
The null hypothesis can be rejected.
Chi^ is a _______?
Test statistic to figure out the p-value.
The value of the expected value could be?
The values if null hypothesis is true.
Assumptions of chi^2 G.o.F. Test? 2•
•No more than 20% of categories have expected < 5
•No category with expected <= 1
Poisson distribution?
Probability that a certain number of events occur in a block of time or space, when those events happen independently of each other and occur when equal probability at every point in time or space.
To determine whether the # of stuff (e.g. flowers) are clumped, random, or dispersed, what do you do?
You put quadrants and take samples per quadrant.
How do you deal with multiple categories if the expected violates the two rules for chi^2?
You can add the variables of the categories.
How to find expected values per category if given probability per category?
Probability * n.
