Dear list, some packages provide functions that allow weighting of the chips, as is the case for normalize.quantiles.robust {affy}, by including a vector of weights. I cannot find information as to how or why to weight chips in an experiment. On what basis do people weight chips? is it something the investigator has to set beforehand or does it depend on quality of chips? are weight values any values in the range of 0-1? I would be grateful if you could shed some light on this and/or direct me to any publications or webpages. Best, David

On Tue, Jul 1, 2008 at 8:10 AM, DAVID ARTETA GARCIA <darteta001 at="" ikasle.ehu.es=""> wrote: > Dear list, > > some packages provide functions that allow weighting of the chips, as is the > case for normalize.quantiles.robust {affy}, by including a vector of > weights. I cannot find information as to how or why to weight chips in an > experiment. > On what basis do people weight chips? is it something the investigator has > to set beforehand or does it depend on quality of chips? are weight values > any values in the range of 0-1? > > I would be grateful if you could shed some light on this and/or direct me to > any publications or webpages. Hi, David. See this thread for some thoughts on array weights. http://thread.gmane.org/gmane.science.biology.informatics.conductor/18 638 Sean