Building and Aggregating Evaluations: The Example of Grading Students

In chapter 2, we tried to show that “voting”, although being a familiar activity to almost everyone, raises many important and difficult questions that are closely connected to the subject of this book. Our main objective in this chapter is similar. We all share the — more or less pleasant — experience of having received “grades” in order to evaluate our academic performances. The authors of this book spend part of their time evaluating the performance of students through grading several kinds of work, an activity that you may also be familiar with. The purpose of this chapter is to build upon this shared experience. This will allow us to discuss, based on simple and familiar situations, what is meant by “evaluating a performance” and “aggregating evaluations”, both activities being central to most evaluation and decision models. Although the entire chapter is based on the example of grading students, it should be stressed that “grades” are often used in contexts unrelated to the evaluation of the performance of students: employees are often graded by their employers, products are routinely tested and graded by consumer organisations, experts are used to rate the feasibility or the riskiness of projects, etc. The findings of this chapter are therefore not limited to the realm of a classroom.