Meanings of measurement

In public domains, performances -- also in ambiguous fields like policing -- are controlled, by making them transparent, by comparing them, and by linking them to targets. Although this ‘numerical capture' of complex phenomena has been heavily criticized, management by measurement is blossoming and in specific cases, measurements like crime monitoring have played a role in reducing crime. The question, however, is whether such improvements are caused by distinctive measurement methods, or by ‘something else'. This paper will analyze how one particular measurement method, the so-called Rotterdam ‘Safety Index', contributed to safety policies. It will show how this dubious instrument is made meaningful; how, indeed, ‘something else' is at work. Political and administrative key players made certain moves in order to ‘link', ‘store', and ‘advocate' the Safety Index. These acts, moreover, occurred amidst distinctive socio-political conditions. Because of ‘acts in context', the Index became a workable tool, producing tangible effects.