We present an application of a clustering technique to a large original dataset of SCI publications which is capable at disentangling
the different research lines followed by a scientist, their duration over time and the intensity of effort devoted to each
of them. Information is obtained by means of software-assisted content analysis, based on the co-occurrence of words in the
full abstract and title of a set of SCI publications authored by 650 American star-physicists across 17 years. We estimated
that scientists in our dataset over the time span contributed on average to 16 different research lines lasting on average
3.5 years and published nearly 5 publications in each single line of research. The technique is potentially useful for scholars
studying science and the research community, as well as for research agencies, to evaluate if the scientist is new to the
topic and for librarians, to collect timely biographic information.