I have a dataset relating the effects of engineering works on the level of salinity in a river before and after the works. I have modelled this using linear mixed effects models to determine if the significance and level of the response to the works. I am wanting to calculate the se of difference at several points. I am not sure of how to calculate the difference and which estimate of se I should be using e.g. is it the random effects or the fixed effects estimates and what formula to use e.g. the one for calculating se using linear models?
To assist here is one of the models I have formulated log(Salinity) ~ log(flow), random=~log(flow)|sites/phase where sites is a factor with levels upstream & downstream, and phase is a factor with two levels before and after. Any help would be appreciated. Tschüß Tony Meissner Principal Scientist - Monitoring Department for Water | Level 3 28 Vaughan Terrace Berri SA 5343 T 8595 2209 | M 0401 124 971 E tony.meiss...@sa.gov.au<mailto:tony.meiss...@sa.gov.au> Mon | Tue | Wed | Thurs | Fri www.waterforgood.sa.gov.au<http://www.waterforgood.sa.gov.au/> | www.sa.gov.au<http://www.sa.gov.au/> The information in this e-mail may be confidential and/o...{{dropped:13}}
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