The Field Survey is a very detailed study of a sample of 1km squares, located all over England, Scotland and Wales. The individual squares are chosen so that they represent all major habitat types in the UK. Enough squares are selected for each type, to make sure that the statistical analysis for that habitat is robust and reliable. The location of the study squares is kept confidential to avoid any deliberate influences that could affect them or the features within them. In this way the sample squares will remain a true reflection of changes in the wider countryside; they will continue to provide a reliable comparison for future Surveys.