ABSTRACT
Should we identify a specifi c student as eligible for special education? What could be the consequence for our students if we use some specifi c teaching method with all of them? How might adopting this method affect the achievement of students who are struggling and those who are not? What might happen to our highest performing students if we do employ a new method? To what extent are we willing to give up achievement gains in our high-performing students or our low-performing students for gains of average students? Do we have to choose between maximum improvement of the average test score and maximum gains in the highest or the lowest test scores? What should we anticipate if we adopt an effective prevention program? Answers to these and many other perplexing questions are not easy, and part of the reason that they are diffi cult is that educators too often ignore the mathematical and statistical aspects of them.
