In 2000, as it happened, I was already familiar, in a glancing sort of way, with a longitudinal study that followed the lives of two hundred and sixty-eight men who graduated from Harvard in the years around 1940.

NEWYORKER: Land of the Seven Moles

Researchers from the Georgia Institute of Technology recently conducted a longitudinal study of follow predictors on Twitter and found that those who were positive and provided informational content gained more followers than those who were negative and shared content about themselves.

FORBES: Grow Your Twitter Followers By Being Nice And Informative

Popkin and his team based their estimate on a 20-year longitudinal study that included more than 5, 100 participants.

FORBES: Cheap Foods That Are Good For You

One night in March, Gonzaga invited me to observe a session that was part of a five-year longitudinal study he is conducting of three hundred and one married couples.

NEWYORKER: Looking for Someone

Here, a study called the Cebu Longitudinal Health and Nutrition Survey has been going on since 1983.

ECONOMIST: Vaccination

The prominent National Longitudinal Lesbian Family Study, for instance, relied on a sample recruited entirely at lesbian events, in women's bookstores and through lesbian newspapers.

WSJ: Nelson Lund: A Social Experiment Without Science Behind It

The University of Michigan's Longitudinal Study of American Youth found last year that married men are cooking 34 meals a month, almost as many as their wives.

WSJ: No, Girls Are Not Natural Baby Sitters