[R] Troubleshooting Type III SS and drop1()

[Bert Gunter]

Omg omg! Search  on "type III as R good or bad" or similar for why you
should of should not be doing this. As for your specific question, I doubt
that you'll get a useful reply until you post the code that elicited the
error. Maybe not even then if it is due to estimability/overfitting of your
data.
And that you cannot obtain an aic seems unsurprising, as you said you
cannot fit the model and so cannot get a likelihood and so cannot possibly
obtain a penalized likelihood.

Or do I misunderstand? If so, please ignore. If not, my best advice would
be to ignore all this SS business altogether and talk with a local
statistician about how or if your data might answer scientific questions of
interest.

Cheers,
Bert
On Jul 16, 2016 6:16 PM, "Pamela Wong" <pamela.wong at mail.utoronto.ca> wrote:

> Hi there
>
> I am trying to compute Type III SS plus model selection and find that an
> error pops up when I'm trying to use the drop1() function with a model
> output using Anova(). I am looking at effects of four factors and their
> interactions (with unbalanced sample sizes across some factor groups), on a
> continuous variable.
>
> I get an error that reads: "Error in terms.default(object) : no terms
> component not attribute". I also can't compute an AIC for the model outputs.
>
> I am wondering if there is something I need to do to my data or if there
> is some limitation to the analysis I am trying to do.
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

	[[alternative HTML version deleted]]