After sending my note I realized that I obscured one fact: When tapply is invoked with names specified for the ... arguments all is well. I should have said that the suggestion for changing tapply would only benefit cases such as tapply(rainfall, state, quantile, c(.25,.75)) where the argument passed through to quantile (probs) was not named. -Frank -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._