Introduction:
Chi Square Test
(
X2
) a test used to tell whether data observed from an experiment is the same
as the data that would be predicted
•
X2
values determine whether test results can be attributed to randomness or not
•
•
Goodness of Fit Test
 a type of statistical test that can determine if any differences
between observed measurements and expected measurements are due to chance or caused by
some other reason (if differences aren’t by chance, then there is actually a relationship between
variables)
•
The Observed Measurements
will be the colors counted from M&Ms
•
The Expected Measurements
will be the claims of the Mars Co. for what each bag
of M&Ms
should
contain
•
•
The Goodness of Fit Test
used in this experiment is the Chi Square Analysis
•
Calculate a statistical value (
)
X2
and use a table to determine the probability that
any difference between observed data and expected data is due to chance
•
•
pvalue
 the probability that something is due to chance
•
A pvalue
of .05 means that there is a 5% chance that the results were coincidental
•
•
Statistically Significant
 the point at which scientists can claim that their results aren’t
due to chance, and that there is actually a correlation between the Independent
and Dependent
Variables
•
Generally accepted as a pvalue
of .05 or lower
•
If a pvalue
is outside the statistically significant range (like p = .1), then that
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '10
 STAFF
 ChiSquare Test, AP Biology, Chisquare distribution, CHI SQUARE, chi square value

Click to edit the document details