Query expansion

A method comprising:

• obtaining session information in a search log;
• determining a vote similarity degree between a single query and a target query based on the session information, including:
• obtaining all queries appearing in a single session,
• calculating a number of votes for each query, the calculating including counting the single query appearing before the target query in the single session as a vote from the single query to the target query, and
• determining the vote similarity degree between the single query and the target query according to the calculated number of votes;
• determining a correlation degree between the single query and the target query based on the vote similarity degree;
• determining a semantic similarity degree between the single query and the target query;
• and
• determining a normalized query based on the correlation degree and the semantic similarity degree between the single query and the target query.

A system for expanding a query, the system comprising:

• one or more processors;
• a memory device communicatively coupled with the one or more processors;
• a query inputting module having instructions, executable by the one or more processors, to obtain a target query;
• a normalized query determining module having instructions, executable by the one or more processors, to determine a normalized query according to the obtained target query;
• and
• a query expanding module having instructions, executable by the one or more processors, to use the normalized query as an expansion term of the obtained target query to implement query expansion,
• wherein the determining the normalized query according to the obtained target query includes:
• obtaining session information in a search log,
• determining a vote similarity degree between a single query and a target query based on the session information, including:
• obtaining all queries appearing in a single session,
• calculating a number of votes for each query, the calculating including counting the single query appearing before the target query in the single session as a vote from the single query to the target query, and
• determining the vote similarity degree between the single query and the target query according to the calculated number of votes;
• determining a correlation degree between the single query and the target query based in part on the vote similarity degree, and
• determining the normalized query based in part on the correlation degree between the single query and the target query.