15. A method performed by a first computing system, the method comprising: receiving, from a second computing system, a message identifying a symptom of a first vehicle; and sending a repair tip to the second computing system, wherein the repair tip comprises: a first phrase describing a first procedure performed on a second vehicle that exhibited the symptom, wherein the first procedure performed on the second vehicle yielded a result insufficient to determine that a component of the second vehicle associated with the symptom is defective; and a second phrase describing a second procedure performed on a given vehicle, wherein the given vehicle is either (i) the second vehicle or (ii) a third vehicle that also exhibited the symptom, wherein the second procedure performed on the given vehicle yielded a result sufficient to determine that a component of the given vehicle associated with the symptom is defective, and wherein the component of the given vehicle is equivalent to the component of the second vehicle.
15. A method performed by a first computing system, the method comprising: receiving, from a second computing system, a message identifying a symptom of a first vehicle; and sending a repair tip to the second computing system, wherein the repair tip comprises: a first phrase describing a first procedure performed on a second vehicle that exhibited the symptom, wherein the first procedure performed on the second vehicle yielded a result insufficient to determine that a component of the second vehicle associated with the symptom is defective; and a second phrase describing a second procedure performed on a given vehicle, wherein the given vehicle is either (i) the second vehicle or (ii) a third vehicle that also exhibited the symptom, wherein the second procedure performed on the given vehicle yielded a result sufficient to determine that a component of the given vehicle associated with the symptom is defective, and wherein the component of the given vehicle is equivalent to the component of the second vehicle. 25. The method of claim 15 , further comprising: identifying a first plurality of phrases stored by the first computing system that each (i) are associated with the symptom and the component of the second vehicle, (ii) convey information equivalent to information conveyed by each of the other phrases of the first plurality, and (iii) include syntax that differs from all other phrases of the first plurality; selecting the first phrase from the first plurality; identifying a second plurality of phrases stored by the first computing system that each (i) are associated with the symptom and the component of the given vehicle, (ii) convey information equivalent to information conveyed by each of the other phrases of the second plurality, and (iii) include syntax that differs from all other phrases of the second plurality; and selecting the second phrase from the second plurality, wherein sending the repair tip to the second computing system comprises sending the selected first phrase and the selected second phrase.