In the context of applying for all kinds of subsidies, the municipality of Parkstad has examined the at- titude of the population towards the policy change 'from black to green', i.e. the (circular) reuse of the industrial heritage. A random sample of the population aged 16 and over were asked a number of questions. In order to determine each respondent's attitude towards the changed policy, the fol- lowing statements were presented, among others (Table 1): Table 1 1. The government must encourage 'circular' projects (i.e. aimed at the sustainable use or reuse of raw materials). 2. Industrial buildings and installations that are no longer in use must be demolished. 3. People who go to live in an apartment that has been cut out of a block of flats (as in Kerk- rade) are divorced from reality. 4. The preservation of old buildings is important for a positive experience of our living environ- ment. 5. Visiting museums and other places that show our history is a fun outing. The respondents were asked to answer using a five-point scale, in which they indicated the extent to which they agreed with the statement. The answers were then converted into a figure as follows: Question 1, 4 and 5 2 and 3 Disagree en- Do not really tirely agree 1 5 2 4 Neither agree Kind of agree Agree entirely nor disagree, 50/50 3 3 4 2 5 1 Explanation: the intention was for a positive attitude towards the policy change to result in higher values. The coding of the negative statements 2 and 3 is therefore reversed. However, the question is whether something like 'a positive attitude towards the policy change' can actually be measured in this way. of the other questions, we will highlight the following: IBA: 'Are you familiar with the IBA (Internationale BauAustellung/International Architecture Exhibition) in Germany?" answer yes (code 1) or no (code 0). Level of education: 'Which education programme did you most recently complete?", with the following answer options: 1- University education (WO), 2- higher professional education (HBO), 3-senior secondary vocational education (MBO), 4-pre-university education (VWO), 5 - senior general secondary education (HAVO), 6-other. Technical points we need to focus on: -The variable education programme must be understood in nominal terms: the idea that one programme is 'higher than another must not be given. The five variables defined in Table 1 should be taken as interval variables. The variable studnr (student number) that appears in the file is not used.