4.4. Scale sustainability
The assessment process requires a clear scale in order to compare and evaluate one thing against another. For effective SIs, tourism planners needto translate tourism indicators, which stakeholders want to measure, into a measurable form. Lee-Smith (1997) points out that, in assessing sustainability, ordinal or interval scales are normally used. For example, Prescott-Allen’s Barometer of Sustainability uses an interval scale of 1–100, which can be mapped onto the ordinal scale: bad–poor– medium–OK–good (Prescott-Allen, 1997). Ordinal scales are relative, not absolute. In many cases, especially where there is a lack of consensus as to what would constitute an adequate standard, ordinal scales may be the only ones available in the interim’ (Clayton & Redcliffe, 1996, p. 198). Ordinal scales could also be used to represent more subtle quality change regarding requirements of local residents, tourists, and the natural environments.