[R-sig-ME] Weights in lmer

[Roberts, Kyle]

Dear All,

Still trying to use the weights function with the ECLS (Early Child Longitudinal Study) with lmer. I think that I have identified the problem, but I am not sure. If a person has a "0" for a weight (they don't have all years of data), how does lmer handle this case? Also, how is the weight treated when you have a stacked format (measurement occasions nested inside students)? For 4 measurement occasions, is the weight multiplied by each of the 4 time points, or does lmer somehow apply the weight at the student level (or does it matter)?

Thanks,
Kyle

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Dr. J. Kyle Roberts
Department of Literacy, Language, and Learning
School of Education and Human Development
Southern Methodist University
P.O. Box 750381
Dallas, TX  75275
214-768-4494
http://www.hlm-online.com/