This article presents the following argument : in many practical contexts of policing, one does not find the conditions conducive to the making of an assessment of a policing program and of its success that follows a strong methodology. We must therefore fall back on weaker methodological designs that are nonetheless useful and valid. The paper is divided in three parts. In the first part, we present a general discussion of the evaluation process, focussing on its object and its method. The second part draws on the material presented in the first to show that satisfying strong criteria in regard to the object of the assessment and to the method of appraisal raises numerous difficulties in a practical context. In particular, performing a thorough assessment is forbidding both in terms of money and time. The third part of the paper describes various economical ways to perform methodologically weaker assessments that satisfy the fundamentals of both theory and practice. In conclusion, we briefly discuss the findings of past evaluative research on community and problem-oriented policing.