Where options differ between countries, i.e. political parties. What we call grid variables , the respondent might pick one, two, three or more alternatives, where each alternative has some kind of graded scale 3. Multiple response, where each option may be mentioned or not mentioned The example below is a very typical two-level question, about attitudes towards rights of homosexuals. To be able to handle all kinds of hierar-chically organised questions, we just need a hierarchical level identifier and a typology for type of question. In addition to the hierarchical possibilities, it is easy to see the usefulness of adding some sideways comparisons.
Variables are of different types.
Some are plain technical or administrative variables, the most interes-ting or important are the weights. Another type are the social back-ground variables, age, sex, occupation, etc. A third type may be the sub-jective opinions expressed, a fourth variety is the derived indexes, and so on. We might go on and differentiate a classification of variables if we find that useful. Obviously it is convenient to easily locate the standard background variables, the geographical references or the collection of derived indexes in the Eurobarometers.