2. The method of claim 1 , wherein selecting the proper subset of the query suggestions comprises: identifying the highest ranked query suggestion based on the ranking; determining which query suggestions of the set of query suggestions are related to the highest ranked query suggestion by referring to the topic of the highest ranked query suggestion or being a revision of the highest ranked query suggestion; and selecting as the proper subset of query suggestions the highest ranked query suggestion and the query suggestions related to the highest ranked query suggestion.
2. The method of claim 1 , wherein selecting the proper subset of the query suggestions comprises: identifying the highest ranked query suggestion based on the ranking; determining which query suggestions of the set of query suggestions are related to the highest ranked query suggestion by referring to the topic of the highest ranked query suggestion or being a revision of the highest ranked query suggestion; and selecting as the proper subset of query suggestions the highest ranked query suggestion and the query suggestions related to the highest ranked query suggestion. 3. The method of claim 2 , wherein determining which query suggestions of the set of query suggestions are related to the highest ranked query suggestion comprises: determining a similarity measure for each query suggestion of the set of query suggestions, the similarity measure being a measure of the similarity of the query suggestion and the highest ranked query suggestion; and determining that each query suggestion having at least a threshold similarity measure is related to the highest ranked query suggestion.