Although many authors believe that their work has a greater research
impact if it is freely available, studies to demonstrate that impact are few.
This study looks at articles in four disciplines at varying stages of adoption
of open access-philosophy, political science, electrical and electronic
engineering and mathematics-to see whether they have a greater im-
pact as measured by citations in the ISI Web of Science database when
their authors make them freely available on the Internet. The finding is
that, across all four disciplines, freely available articles do have a greater
research impact. Shedding light on this category of open access reveals
that scholars in diverse disciplines are adopting open-access practices
and being rewarded for it.