Unformatted text preview: ) = df s + df s + L + df s
2 11 2 2 2 k 2
k 21 OneWay ANOVA
OneWay The within group variation for our example is 3386 SS ( W ) = 6 ( 310.90 ) + 8 ( 119.86 ) + 7 ( 80.29 ) SS ( W ) = 3386.31 ≈ 3386 22 OneWay ANOVA
OneWay After filling in the sum of squares, we have … Source SS Between 1902 Within 3386 Total df MS F p 5288
23 OneWay ANOVA
OneWay Degrees of Freedom, df A degree of freedom occurs for each value that can
degree
vary before the rest of the values are predetermined
vary
For example, if you had six numbers that had an
For
average of 40, you would know that the total had to
be 240. Five of the six numbers could be anything,
but once the first five are known, the last one is fixed
so the sum is 240. The df would be 61=5
so
The df is often one less than the number of values 24 OneWay ANOVA
OneWay The between group df is one less than the
The
number of groups
number The within group df is the sum of the individual
The
df’s of each group
df’s We have three groups, so df(B) = 2 The sample sizes are 7, 9, and 8
df(W) = 6 + 8 + 7 = 21 The total df is one less than the sample size df(Total) = 24 – 1 = 23
25 OneWay ANOVA
OneWay Filling in the degrees of freedom gives this … Source SS df MS Between 1902 2 Within 3386 21 Total 5288 F p 23
26 OneWay ANOVA
OneWay Variances The variances are also called the Mean of the
The
Squares and abbreviated by MS, often with an
accompanying variable MS(B) or MS(W)
accompanying
They are an average squared devi...
View
Full Document
 Spring '13
 mrs
 Variance

Click to edit the document details