Considering Long Data

In Wired:  When I first saw this headline, I thought, Oh, Longitudinal data.   Which means you follow one agent or actor in a system and get data about them over time.   A common  enough thing in health studies.    Also needed in many kinds of forecasting.  So should we pay more attention to the 'length' of data rather than its size?   " ... But no matter how big that data is or what insights we glean from it, it is still just a snapshot: a moment in time. That’s why I think we need to stop getting stuck only on big data and start thinking about long data....  ".   But this can often imply that external contexts of a set of data over time remains constant.  As the length of your data gets larger, this is less likely. I like the idea, it should always be considered, but with caution.