To compensate for the unidimensional nature of each indicator, it is necessary to build a system of indicators, that is, a coherent set of indicators that together provide a valid representation of the condition of a particular education system, not just an ad hoc collection of readily available statistics. Ideally, an indicator system will provide information about how individual indicator components work together to produce an overall effect. In other words, the policy and interpretative value of all the information to be gained from a system of indicators is greater than the sum of its parts. To provide this overall picture, the selected indicators should be logically or empirically linked. The linkages should proceed from a model or framework that describes how the education system works. The model by itself permits the broader assessment of an indicator’s relevance (OECD/CERI, 1992: 15).
For most countries, the appearance of indicators and indicator systems in higher education constitutes a response to two policy objectives: exercising more rigorous monitoring in this field and, in times of fiscal restraint, establishing a more direct and observable link between funding and performance. The goal of using a system of indicators is to make the autonomy and diversification of higher education institutions compatible with accountability and effective management of these institutions. Indicators thus provide a means of not only external monitoring of these institutions by governments, but also internal monitoring of overall institutional goals or specific ones set by departments or service units (Martin and Sauvageot, 2009: 20).