Later in this chapter we shall be considering various definitions or interpretations of the concept ‘evaluation’ in order to see how it differs from other forms of assessment in the public sector. ‘Interpretation’ is probably the more accurate term to apply since this allows for nuances of meaning which are attached to the concept, rather than ‘definition’ which implies that there is only one meaning. However, ‘definition’ will be used at appropriate points in the discussion, because writers on this topic usually offer their interpretations as if they are indeed the meaning.

As noted in Chapter One, during the 1980s and 1990s in the UK the government needed to ensure that public expenditure was allocated to services on the basis of value for money – in short, where was the evidence that projects, programmes and, in particular, policies had achieved their objectives at the least possible cost? Some of these objectives could be expressed in terms of outcomes but it was also considered essential to concentrate efforts on attaining quantifiable targets which were labelled ‘performance indicators’ (PIs). Semantically, the term ‘indicator’ would seem to be well-chosen. An indication of achievement implies that the chosen indicator might not tell the whole story; that there might only be a prima facie connection between some quantifiable index and ‘performance’. The temptation has been to use PIs not only as proxy measures of successful policies, but as if they were the only measurements that were necessary. We shall now deal with a number of approaches to and techniques of performance measurement and, later in this chapter, we shall examine whether there is consensus about the nature and purpose of evaluation.

Measurement of performance

How does evaluation differ from other forms of assessment in the realm of public sector performance? Are the criteria for judging merit that are applied in auditing, inspection and accreditation less rigorous or less valid than those used when carrying out formal evaluations? Are the results recorded in audit, inspection and accreditation reports accepted more readily by decision makers than those generated by evaluation research?