Downweight

In addition, both adaptive and robust methods downweight outliers. Note that, if a large sample is taken, the M-estimation procedure will generally downweight some of the largest residuals, even if the error terms were normally distributed.

Piano technicians have to measurements at their disposal for measuring touchweight: downweight and upweight. Downweight and upweight are measured in grams. To measure downweight, a gram weight is placed on the key at the front and a rap or thump is given to the shop bench, KEYBED, or action stack with one's fist to break the starting friction