Greetings. On Sun, 7 Apr 2002, Glen Barnett wrote: > Assuming you *can* take average student abilities across classes as equal
Who said that we are sampling across classes? I was thinking of the case where the assignments from a single large class are randomly divided among several graders for marking, and one of the graders is an outlier. > there are a variety of ways you might match mean and s.d., > but the obvious one is the linear transformation you get by > multiplying the B group's marks by the ratio of standard deviations (r > = s_A/s_B, making the new sd equal to s_A), and then adding the > difference d = x_A - r x_B. Thanks, this is exactly what I'm looking for. :) On 6 Apr 2002, Jay Warner wrote: > I would be more concerned that the graders can interpret the answers > in such blatantly different ways. Perhaps the students do the same, > which begs the question of the precision & usefulness of the > questions. Reviewing the questions with your graders might tighten up > your (instructor's) part of the process. I am aware that the best solution in this case is preventative rather than corrective, but unfortunately situations do arise where the damage has already been done, and redesigning or remarking the assignment is not practical. In such cases the regulations of my university mandate a linear scaling of the affected grades, hence my query. I hope that my assignments will be so clearly specified and my markers so clearly instructed that I will never have need of such a scaling, but I wish to be prepared for all possibilities. -- \\\ Tristan Miller \\\ Department of Computer Science, University of Toronto \\\ http://www.cs.toronto.edu/~psy/ . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
