The number of software engineering research papers over the last few years has grown significantly. An important question here is: how relevant is software engineering research to practitioners in the field? To address this question, we conducted a survey at Microsoft where we invited 3,000 industry practitioners to rate the relevance of research ideas contained in 571 ICSE, ESEC/FSE and FSE papers that were published over a five year period. We received 17,913 ratings by 512 practitioners who labelled ideas as essential, worthwhile, unimportant, or unwise. The results from the survey suggest that practitioners are positive towards studies done by the software engineering research community: 71% of all ratings were essential or worthwhile. We found no correlation between the citation counts and the relevance scores of the papers. Through a qualitative analysis of free text responses, we identify several reasons why practitioners considered certain research ideas to be unwise. The survey approach described in this paper is lightweight: on average, a participant spent only 22.5 minutes to respond to the survey. At the same time, the results can provide useful insight to conference organizers, authors, and participating practitioners.