A machine-implemented search method comprises inputting a search query from a user, and before the query is executed, inputting from the user a weighting factor that has a specified relationship to the query. The method further includes initiating a search by causing the query to be applied according to the weighting factor, and returning a result of the search to the user. The weighting factor may represent, for example, a weight to be given to one of multiple information sources that are available to be searched in response to the query, such as an online search engine or a merchant online commerce web site. Alternatively, the weighting factor may represent a weight to be given to a term in the query.