▪ Improving results ▪ For high recall. ▪ E.g., searching for aircraft doesn’t match with plane; nor thermodynamic with heat ▪ Options for improving results… ▪ Local methods ▪ Relevance feedback ▪ Pseudo relevance feedback ▪ Global methods ▪ Query expansion ▪ Thesaurus ▪ Automatic thesaurus generation