Ideally an evaluation plan should be drawn up and agreed by all those who are party to the evaluation, including those who will have to be interviewed or consulted. It is difficult to be prescriptive about what should be in an evaluation and, anyway, because each evaluation is unique, it would be wrong to prescribe a general set of issues to be covered. In the past it has sometimes been supposed that quantitative methods, collecting facts and figures, were appropriate only to summative evaluation and that softer, qualitative, methods such as life histories, story telling and self reflection were only appropriate to formative evaluation. In fact all these methods are valuable and a good evaluation, whether it be summative or formative, should draw as appropriate from both qualitative and quantitative approaches. Quantitative methods are appropriate in measuring resource inputs, outputs and costs.
Quantitative analysis is also appropriate where there are good sources of data about the project.
These data might describe project participants or clients, or they might be the quantitative results of studies on changes in participants attitudes or behaviour. Typical methods would be in-depth interviews, case studies , focus groups, life histories, story telling etc. Qualitative methods flesh out hard quantitative data and give a real feel for the achievements of a project or group. Many people and organisations offer evaluation services. These range from management consultants to academics, researchers and professional evaluators.