(3) Qualitative or quantitative data can be used to produce information for the standard. However, quantitative data may include more advantages than qualitative data in making a sustainability assessment. This does not mean that quantitative data is more scientific or more advanced as a technique than qualitative data. They are complementary, and both incorporate merits and demerits. (4) A perception study, administered through questionnaire surveys or other surveys, is suggested to produce the quantitative data. Perception study is already used widely in many areas to measure the socio-economic impacts of tourism and the quality of service and products. In particular, this perception study is useful in assessing the sustainability of a particular tourist destination, where technical data, regarding tourism activities, are not available. (5) In order to produce quantitative data with the perception study, a 10-point rating scale survey is suggested. While rating scales typically range from 1 to 5, the 10-point
rating scale can be introduced to facilitate the adaptation of the results to the tourism sustainability assessment maps (TSAMs). (6) Four kinds of gradations of sustainability are suggested. Although the two divisions (sustainable vs. unsustainable) are most commonly used, they may vary as measurement processes become sophisticated.
(7) Two types of TSAMs are suggested. The comprehensive level of sustainability of the human system and the ecosystem can be defined and illustrated by the BTS. Following the four types of sustainability gradations mentioned above, four BTS models (BTS1– 4) are suggested. The BTS models are very useful to present the current sustainability of a tourist destination to stakeholders. (8) The sustainability of individualised tourism indicators can be defined and illustrated by the AMOEBA of tourism sustainability indicators.
Following the four types of sustainability gradations mentioned above, four ATSI models (ATSI1–4) are suggested. The ATSI models are used to complement the simplicity of the BTS models, and to explain the complexity and diversity of tourism aspects, by illustrating sustainability of individualised tourism indicators. (9) The BTS and ATSI analysis can be extended over time. They might move over the surface of the square (or the circle) with each significant movement indicated by the sustainability indicators (SIs) from the standpoint of stakeholders. (10) Where the TSAMs are used together, these model numbers must be matched accordingly (e.g. BTS1 with ATSI1, 2 with 2, 3 with 3 and 4 with 4). Thus, the comprehensive and individual level of sustainability in a tourist destination can be simultaneously presented by these BTS and ATSI models.