This International Standard provides guidance for the design of field studies with soil invertebrates (e. g. for the monitoring of the quality of a soil as a habitat for organisms). Detailed information on the sampling of the most important soil organisms is provided in the other parts of this International Standard (ISO 23611-1 to ISO 23611-5). This International Standard is used for all terrestrial biotopes in which soil invertebrates occur. Basic information on the design of field studies in general is already laid down in ISO 10381-1. This information can vary according to the national requirements or the climatic/regional conditions of the site to be sampled. NOTE While this standard aims to be applicable globally for all terrestrial sites that are inhabited by soil invertebrates, the existing information refers mostly to temperate regions. However, the (few) studies from other (tropical and boreal) regions as well as theoretical considerations allow the conclusion that the principles laid down in this International Standard are generally valid [4], [6], [40], [21]. This document gives information on site-specific risk assessment of contaminated land, study of potential side effects of anthropogenic impacts (e. g. the application of chemicals or the building of roads), the biological classification and assessment of soils in order to determine the biological quality of soils and long-term biogeographical monitoring in the context of nature protection or restoration, including global change (e. g. as in long-term ecological research projects).