14. The one or more non-transitory storage media of claim 13 , wherein: removing the certain term from the second text string comprises adding the certain term to a third list that is different than the first list and the second list; and the instructions, when executed by the one or more processors, further cause, prior to performing a second search: determining whether the second text string is empty; in response to determining that the second text string is not empty, replacing the first list with the third list.
13. One or more non-transitory storage media storing instructions which, when executed by one or more processors, cause: while a first text string is being formed, creating a first list; classifying each of one or more terms, of the first text string, as a bad term, wherein a term is classified as a bad term if a search that was performed using the term yielded no search results; adding the one or more terms to the first list; creating a second list; classifying each of one or more second terms, of the first text string, as a good term, wherein a particular term is classified as a good term if a search that was performed using the particular term yielded one or more search results; adding the one or more second terms to the second list; performing a first search based on the first text string; based on the first search, identifying one or more search results; after identifying the one or more search results, causing the one or more search results to be displayed; while the one or more search results are displayed, receiving first input that changes the first text string to a second text string; determining whether a certain term in the second text string begins with a term in the first list; in response to determining that the certain term in the second text string begins with a term in the first list, removing the certain term from the second text string; determining whether the certain term begins with a term in the second list; in response to determining that the certain term begins with a term in the second list, adding the term in the second list to the second text string.