Eric Lund wrote: > > In Indiana, the school accountability legislation calls for locally > produced assesments to be used. An assessment is to be given to about > 1600 students in the high school in which I teach. This assessment > will be given each September and May starting with the 2003-2004 > school year. How large of a sample must be drawn from this population > in order to approximate the mean score for all of the students? Is it > possible to determine the size of the sample if there is no baseline > data for this population with regards to this particular assessment?
Issues of legality of sampling aside, (1) you cannot determine sample size without an estimate of variability (2) you can take a small sample to get an estimate of variability (3) pooling the data from (2) with data collected subsequently does affect things, but not too much. . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
