Evaluation This lecture How do we know if our results are good? Evaluating a search engine Benchmarks Precision and recall Results summaries. Making our good results usable to a userEvaluation 2 This lecture ▪ How do we know if our results are good? ▪ Evaluating a search engine ▪ Benchmarks ▪ Precision and recall ▪ Results summaries: ▪ Making our good results usable to a user