The original of CH13-Q9 is given by question.
Df of constant model is7, so df of original data is 8.Only for this question.
What tutor said means constant always existed in calculation.
The formal calculation is a kind of incremental algorithm of decreasing df.
It is "The starting point for a variable 2 for a factor the number of categories or for a constant 1
You only deduct the additional parameters each time for degrees of freedom"
For example,the last one in formal calculation become
YO*FS*TC=Constant+YO+FS+TC
+YO.FS+FS.TC+YO.TC
+YO.FS.TC
=1+(2-1)+(2-1)+(2-1)
+(2-1)*(2-1)+(2-1)*(2-1)+(2-1)*(2-1)
+(2-1)*(2-1)*(2-1)
=8
It is "The constant is there but it has been combined into another parameter in the revised model".
"What do parameters and dof represent in this context?"
The parameters in equation.
all same category:YO0.FS0.TC0,YO1.FS1.TC1
one 1 category:YO0.FS0.TC1,YO1.FS1.TC0,YO1.FS0.TC0
two 1 category:YO1.FS1.TC0,YO1.FS0.TC1,YO0.FS1.TC1
This is what I understand from response of assignment X4-8 from tutor.
Last edited: Apr 12, 2023