topic Re: Lack of Fit missing in Discussions

Lack of Fit missing

Joon — Sat, 14 Apr 2018 06:13:14 GMT

Hi~

When I study fit model, I have a simple problem. As you see below image, I want to know why "Lack of Fit" is not activated, this sample data just from JMP library.

Re: Lack of Fit missing

txnelson — Sat, 14 Apr 2018 13:21:24 GMT

The documentation for the Fit Model Platform has the following statement:

In the following situations, the Lack of Fit report does not appear because the test statistic

cannot be computed:

• There are no replicated points with respect to the X variables, so it is impossible to

calculate a pure error sum of squares.

• The model is saturated, meaning that there are as many estimated parameters as

there are observations. Such a model fits perfectly, so it is impossible to assess lack of fit.

The documentation is available from the pull down menus in JMP:

Help==>Books==>Fitting Linear Models

Re: Lack of Fit missing

Joon — Sun, 15 Apr 2018 09:33:58 GMT

Thanks a lot, I have to study more with Books that you recommanded~