Hello everyone, and thanks for all of your contributions which I have read with interest. I am Peter Midmore, coordinator of the IMPRESA project and professor of economics at Aberystwyth University. My first contribution to this debate is to follow up Messages 13 (by Amadou Binta Ba) and 15 (by Matthieu Stigler) and discuss case study selection issues. While I am a fan of the approach in general for its ability to deal with complex, multi-effect processes at a system level, and its relevance in participatory evaluation, in recent years I have been concerned about the process of selection and whether "interesting" cases which appeal to researchers might have a higher chance of selection, attracting more and earlier attention. There is in fact a substantial literature from the international relations discipline (see Bennett and Elman, 2006, for a recent review) and suggestion that there might be a temptation to choose only comparative cases that demonstrate the hypothesised relationship between independent and dependent variables. While much of the wrangling is based on an inductive perspective that seeks generalizability from cases - which is in my view irrelevant to the generation of insights that should emerge - nevertheless, given my concern above, it might be possible to accidentally select biased case studies for evaluation. In evaluating the impacts of agricultural science research, therefore, I think there is a requirement for an active search for disconfirming evidence to be built into selection of comparative cases. My question is whether any participants can draw my attention to evaluation studies which have used this validation approach? I don't think any exist in European agricultural research impact evaluation, but I would be keen to hear of experiences from elsewhere. Reference: Bennett A and Elman C (2006) Qualitative research: recent developments in case study methods, Annual Review of Political Science, 9, pp. 455-476. Peter Midmore Professor of Economics School of Management and Business Llanbadarn Centre Aberystwyth University SY23 3AL United Kingdom Phone: +44 (0)1970 622251 Fax: +44 (0)1970 622740 e-mail: Pxm (at) aber.ac.uk [To contribute to this conference, send your message to [log in to unmask] For further information, see http://www.fao.org/nr/research-extension-systems/res-home/news/detail/en/c/217706/ ]. ######################################################################## To unsubscribe from the Impact-L list, click the following link: https://listserv.fao.org/cgi-bin/wa?SUBED1=Impact-L&A=1