longitudinal
lon-juh-TOO-di-nul
Definition
Describing a research study that observes the same subjects repeatedly over an extended period of time to track changes.
Etymology
Derived from the Latin 'longitudo' meaning length, the term originally referred to measurement along the length of an object or geography before being adopted in statistics to describe studies that extend across the length of time.
In the news
The article uses the term to describe a study that tracked couples over two and a half years, distinguishing this ongoing observation from static cross-sectional data.
A divorce-prediction equation was 90 percent accurate on the data it was built from, but when it flagged a couple as heading for divorce in a fresh sample it was right only 29 percent of the time, which is the trouble with rules like these
Read the full article ↗ScienceBlog.com