Plural nouns treated as singular
Some plural nouns are treated as singular, in all or in certain meanings. These include the names of branches of knowledge or science, such as acoustics and mathematics, activities such as billiards and gymnastics, and diseases such as measles:
Acoustics is taught as part of the extended course.
The figures show that measles is on the increase.
You'll also find that some other plural nouns, such as data and media, are now often treated as singular. Data is a special case. In scientific writing, data is usually treated as a plural:
The data were tested for reliability.
In everyday use, it's more usual to treat data as a singular, with a singular verb:
Raw data by itself is of no value to the business decision-maker.