NCBI is a primary database . it stand for national center for biotechnology information.

David Lipman is the Director of the National Center for Biotechnology Information at the National Institutes of Health

Information on frequency distribution can be found on many sites related to psychology and biotechnology. The About's Psychology page offers a good overview on the topic while the National Center for Biotechnology Information has a more in depth reading.

NCBI (The National Center for Biotechnology Information) conducts scientific research. Specifically, they do research on genomic and biomedical information to advance our knowledge in health and science.

The National Center for Biotechnology Information, or the NCBI, is a branch of the United States National Library of Medicine, or the NLM. With access to the NCBI, one can't acquire very much unless one has a patient's medical information.