MEDLINE Baseline Repository
                          Histogram/Summary README File
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NOTES:
  1) All counts are based solely on MeSH Headings.

  2) We use the Date Completed date to determine inclusion in the counts for
     each baseline.

  3) We are using the MeSH assignment of Semantic Type for the MeSH Headings
     wherever possible.   Where a Semantic Type was not found in the MeSH
     dYYYY.bin file for a given MeSH Heading, we manually determined the
     Semantic Type(s) via the UMLS MRCON and MRSTY files.

  4) The hist_Full and histST_Full files which report on the entire MEDLINE
     baseline were created using the latest MeSH Vocabulary, 2004 in this
     case.  This means that some counts may be different in this overall
     file than what is seen in the 2002 and 2003 baseline count files.
     The 2004 MeSH was used to provide consistency with using the 2004 Baseline
     to create the two files.


hist:
  A count of MeSH Main Headings partitioned into the respective MeSH
Treecodes for this year.  We include counts for the top-level (e.g.,
"A", "B") and top-level plus one (e.g., "A01", "A02, "B01") MeSH Treecodes
based on the MeSH Vocabulary specific to each baseline year.


hist.pdf:
  A graph generated from the respective hist file data.


histST:
  A count of UMLS Semantic Types partitioned into the respective high-level
UMLS Semantic Groupings.


histST.pdf:
  A graph generated from the respective histST file data.


hist_Full:
  We use the same methodology we used in the above "hist" file, but,
apply it across the entire MEDLINE and report counts for each of the
years (1965 - 2003) in the MEDLINE Baseline.  This file is provided for
comparison purposes to see how assignments have changed over the years.
NOTE: This file is created using the 2004 MeSH Vocabulary, so the numbers will
      differ from the 2002 and 2003 baseline counts.


hist_Full.pdf:
  A graph generated from the respective hist_Full file data.


histST_Full:
  We use the same methodology we used in the above "histST" file, but,
apply it across the entire MEDLINE and report counts for each of the
years (1965 - 2003) in the MEDLINE Baseline.  This file is provided for
comparison purposes to see how assignments have changed over the years.
NOTE: This file is created using the 2004 MeSH Vocabulary, so the numbers will
      differ from the 2002 and 2003 baseline counts.


histST_Full.pdf:
  A graph generated from the respective histST_Full file data.


combined_hist.pdf:
  A graph generated from the "hist" methodology results for all of the MEDLINE
Baselines currently in the Repository for comparison purposes.


combined_histST.pdf:
  A graph generated from the "histST" methodology results for all of the
MEDLINE Baselines currently in the Repository for comparison purposes.