Objective as time-independent

In her article on the then-latest breast cancer screening research, 538-science writer Christie Aschwanden noted

Welch’s group has published other studies with similar results. One of those categorized cancers according to stage, rather than size, however, and some critics countered that the way that cancers are categorized has evolved, which could make comparisons difficult. So in this latest study, the researchers looked at size — a measure that is objective and hasn’t changed over time — and came to the same conclusion: Mammography produces an increase in the number of women diagnosed and treated for breast cancer and a non-invasive cancer called ductal carcinoma in situ (DCIS), but it doesn’t do much to prevent the deadliest cases.

The main point I wish to draw attention to is the distinction between evolving categories, such as cancer stages, and the measurement of size. Though her precise wording, namely that size is an objective measure, is contestable, Aschwanden's phrasing suggests that the crucial difference is the one between evolving and categories that remain constant for a duration of research.

Now granted, this is not what people mean when they use the word "objective", but perhaps it is a better meaning for the word than the current one, which seems to imply some socially indisputable common ground.