Error in R using lmer: boundary (singular) fit: see ?isSingular

[vmengler]

I am an undergraduate student trying to use the function lmer to create some models in R and I keep recieving this error message:

</> boundary (singular) fit: see ?isSingular

I am using dummy variables and so perhaps the package doesn't like my dummy variables, but I'm not sure. I've been looking online other places and once website suggested that "the model is likely overfitted and/or suffers from numerical stability issues". Could this be the case? What should I do in order to properly build my models? Thank you for the help!

[andresrcs]

Hi!

To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one:

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…