Abstract
The aim of this paper is to examine the role of indicators in the transition to sustainability in tourism development and planning, identifying their main characteristics and summarising the challenges posed by their use in tourism development and in the research field. Indicators today constitute significant elements in sustainability programmes, but their use has been hampered by technical and conceptual difficulties. Furthermore, given that specific socio-spatial contexts and scales are highly influential in their application in the field, there is a need to identify the nature and characteristics of these indicators of sustainable tourism. After the in-depth development of a theoretical and phenomenological framework for indicators in tourism sector based on literature review, some interesting findings were identified. Indicators of sustainability have been widely adopted in tourism planning and management, and the indicator type (set or index) is selected depending on the situation under analysis and the purpose underpinning the study. In general, a set of indicators may prove more useful and accurate for assessing sustainability in one tourism destination, while an index may be better suited for comparing different spatial units. However, indicator effectiveness to achieve the ideals of sustainable tourism development is affected by the ambiguity in the definition of the concept of sustainable tourism and problems associated with data availability and baseline knowledge. The main challenge is to overcome strategic guidelines and political and theoretical proposals of indicators and achieve practical applications for the sustainable development of tourism. It is in this regard that innovations and knowledge transfer have been stressed, albeit that the nature of this knowledge remains the key.