After the Science Citation Index was launched in the '60s, we soon learned that the age of the average cited paper, depending upon the field, was 5 to 15 years old. In molecular biology, while 25 percent of cited papers were about 2 years old, the rest were much older. These data initially obscured the fact that a small group of papers were well cited within months of publication. It wasn't until 1975 that a series of essays in Current Contents identified the 100 most-cited life science papers published in the current year.1
Two years after we started The Scientist, we began a feature called "Hot Papers." A group of experts was assigned the "subjective" task of compiling lists of current articles they considered to be significant--that is, "hot." These selections were not based on "objective" citation data. However, the process proved to be problematic.
In February 1989,2 I announced ...
