Both quantitative and qualitative data can usefully contribute to a programme evaluation. The balance between the two is likely to be determined by your objectives for the evaluation and the available budget.

• Quantitative data– provide measures, for example of how many people attended the event and what they thought of it. The same questions should be used throughout the evaluation and responses gathered from a representative sample. Often all participants are asked to fill in a questionnaire (sometimes before and after if knowledge change is being measured). 
• Qualitative data – seek to illuminate individual experiences and provide additional subjective context to the evaluation. These data explore the participants’ experience in more depth than quantitative data. Methods vary from the inclusion of open questions on a survey to interviews.Sampling should include a cross-section of participants. 
• Observational data – exploring how people participate in an event can be illuminating. Did they participate in all events/activities? Were some aspects more popular than others? How did people interact with your website or display? A clear idea of what you are looking for is important when structuring observational data. 
• Project team records – keeping an evaluation journal allows the programme team to explore and reflect on the process of developing and delivering the project.