Region Search Trees
The two-level REGION search trees facilitate the questions in the survey that address domiciliary region, region of birth and region of work. To answer these questions, respondents are presented with a radio button list of options tailored to the country of survey. These lists are presented over two levels: respondents first select an option from a list of regions (regihom1), then a more specific option within that region (regihom2). At the second level, the larger or more significant population settlements for each region are listed by name, along with a series of generic options for people who don’t live in one of the places specifically listed. Usually these are: ‘A town (100,000 - 1 million)’ ‘A small city (10,000 - 100,000)’; ‘A village (less than 10,000)’; and ‘Rural area’, though the descriptions relating to the different degrees of urbanisation are often adapted for local suitability – a settlement of 100,000 people might be considered a town in one country but a city in another. In any case, all options in the region search trees are coded in such as way that the degree or urbanisation can be discerned (please see Explaining the dataset for more information). In addition to the national regions, the first level of the REGION search tree includes an option ‘Abroad’, followed in the second tier by a list of neighbouring countries, in order to capture border work.