Figure 2. The Impact of Challenge Evaluations (and Investment Dollars).

Driven by investment and competition as well as the pressure of regular challenge evaluations, error rates in speech recognition have dropped steadily, to the point where the technology has become standard from directory assistance to travel to financial information. Error rates drop by a factor of two every two years as challenge evaluations attract wide participation. (Graph adapted with permission from the MITRE Corporation.) Source: Pallett D, Garofolo J, Fiscus J (2000) Measurements in support of research accomplishments. Communications of the ACM: Special section on broadcast news understanding.