Taking maintenance costs into account

The final consideration for natural language applications, especially deployed applications, is the cost of maintenance. This is easy to overlook because NLU applications have several maintenance considerations that don’t apply to most traditional applications. Specifically, the type of language used in some applications changes over time. This is expected since it reflects changes in the things that the users are talking about. In customer service applications, for example, product names, store locations, and services change, sometimes very quickly. The new vocabulary that customers use to ask about this information changes as well. This means that new words have to be added to the system, and machine learning models have to be retrained.

Similarly, applications that provide rapidly changing information need to be kept up to date on an ongoing basis. As an example, the word COVID-19 was introduced in early 2020 – no one had ever...