Enterprise Search, 2nd Edition

Chapter 4. Query and Results Management

Chapter 3 described the technology as far as the index being created. The next two steps in the search journey are to find the documents that match a query and then to provide a list of the documents ranked in descending order of relevance. This is where the search technology becomes more visible. At the risk of an inappropriate generalization, all search applications work along the lines set out in Chapter 3. It is in the management of queries and results, and in the display of results (described in Chapter 12), that differences become more obvious.

Query Management

Query management presents some substantial processing challenges. In the case of indexing, there is an enormous amount of information that the indexing process can use to “understand” the nature of the information content. Users then type in a single word and expect the search engine to undertake a mind meld and work out what the query is really about. The query processing stage has to be able to undertake four processes very quickly:

• Check for obvious spelling mistakes and offer suggestions for correct spellings

• Use stemming and lemmatization to develop a range of potential query terms

• Identify entities or phrases that may need to be clarified or expanded

• Apply some semantic analysis to gain an insight into the likely nature of the query

A good example of query management in action can be seen on the public website of Microsoft. Typing the word SharePoint will cause ...