Message-ID: <3a433f9c-14e9-31e3-abea-36077616d368@ed.ac.uk>
Date: 2018-06-19T08:04:22Z
From: Jarrod Hadfield
Subject: Using variance components of lmer for ICC computation in reliability study
In-Reply-To: <6774750.Z77ZOZtpCQ@ev8sa6>
Hi,
No - the residual variance is non-identifiable in a threshold model
irrespective of the number of thresholds unless the thresholds are
constrained in some way (e.g. fully constrained as in the paper I
previously referenced). Strong depletion from the central category would
simply mean the two thresholds are close together.
Cheers,
Jarrod
On 19/06/2018 08:38, Pierre de Villemereuil wrote:
> Hi,
>
>> Maybe there is information about the residual variances in the 2-threshold model in such a setup?
> Maybe, but it would be quite hard (if possible at all) to distinguish from changes in the mean, wouldn't it? Unless the changes in the "spreading" are quite dramatic and located in the extreme categories with a strong "depletion" from the central one.
>
> It's interesting to think about it though.
>
> Cheers,
> Pierre.
>
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