MELVYL MEDLINE DATABASES TELNET STATISTICS                       
                 Time period: 04/01/99 through 04/30/99                         
                                                                                
                                                                                
1.0  SUMMARY STATISTICS                                                         
_______________________                                                         
                                                                                
  Sessions:         Medical/Health/                                             
                      Life Sciences   All Other                                 
                          Libraries   Libraries      Remote       Total         
                    _______________   _________   _________   _________         
    Berkeley                      0       3,604       7,429      11,033         
    Davis                       363       6,477       1,322       8,162         
    Irvine                        0       5,316           0       5,316         
    Los Angeles                   0       4,690       2,360       7,050         
    Riverside                     2         514         858       1,374         
    San Diego                 1,124       5,176         940       7,240         
    San Francisco               820           0      17,083      17,903         
    Santa Barbara                 0         353         608         961         
    Santa Cruz                  857         250         858       1,965         
    Stanford                                                      4,873         
    Other (including DLA)         0           0      17,331      17,331         
                    _______________   _________   _________   _________         
    Total:                    3,166      26,380      48,789      83,208         
                                                                                
                                                                                
  Relative use of MEDLINE databases                                             
                                                                                
                       Number of     Number of        Number of                 
                       Sessions      FIND commands    Records Displayed         
                       ________      _____________    _________________         
    MED (current)        59,432          200,676              2,310,955         
    MED90 database       10,430           24,365                224,077         
    MED85 database        5,793           12,126                 95,412         
    MED80 database        3,732            7,580                 53,745         
    MED75 database        2,281            4,698                 35,635         
    MED66 database        1,540            3,525                 32,185         
                                                                                
                                                                                
  Per hour usage:                                                               
                                                                                
          Time         Sessions            Finds      Records Displayed         
    __________       __________       __________      _________________         
    12-2  a.m.              991            3,042                 44,514         
     2-4  a.m.              302            1,018                  9,326         
     4-6  a.m.              284              691                 10,482         
     6-8  a.m.            1,305            4,002                 37,146         
     8-10 a.m.            8,116           23,787                230,266         
    10-12 a.m.           15,407           45,636                467,659         
    12-2  p.m.           14,804           44,311                446,833         
     2-4  p.m.           17,319           53,035                558,190         
     4-6  p.m.           12,575           38,831                492,624         
     6-8  p.m.            5,798           18,039                211,428         
     8-10 p.m.            3,921           12,555                148,034         
    10-12 p.m.            2,386            8,023                 95,507         
    __________       __________       __________      _________________         
        Total:           83,208          252,970              2,752,009         
                                                                                
                                                                                
  Session length (minutes:seconds):                                             
                                                                                
                    Medical/Health/                                             
                      Life Sciences   All Other                                 
                          Libraries   Libraries      Remote       Total         
                    _______________   _________   _________   _________         
    Assist:                                                                     
      Average                    0.0         0.0         0.0       0:00         
      Median                     0.0         0.0         0.0       0:00         
    Command:                                                                    
      Average                 15:25       13:56       13:58       13:50         
      Median                  10:12        8:32        8:35        8:29         
    Total:                                                                      
      Average                 15:25       13:56       13:58       13:50         
      Median                  10:12        8:32        8:35        8:29         
                                                                                
                                                                                
  Response time (in seconds):                                      Std.         
                                                          Avg.     Dev.         
                                                        ______   ______         
    Search  - from receipt of command at DLA until         1.0      3.5         
              transmission of response                                          
    Display - from receipt of command at DLA until         0.1      0.2         
              transmission of a complete screen                                 
                                                                                
  Use of Assist vs Command mode:            Number of     Percentage of         
                                             Sessions          Searches         
                                            _________     _____________         
    Assist mode                                     0              0.0%         
    Command mode                               83,208              100%         
                                                                                
  E MED option:                                                                 
    E MED chosen from Welcome screen                        0                   
    E MED chosen from Assist screens                        0                   
                                                                                
    Specific screens chosen from within E MED:                                  
      Master Menu                                           0                   
      FIND command                                          0                   
      FIND command examples                                 0                   
      DISPLAY command                                       0                   
      DISPLAY command - other options                       0                   
      BROWSE command                                        0                   
      BROWSE DISPLAY options                                0                   
      SELECT command                                        0                   
      Assistance commands                                   0                   
      START and END commands                                0                   
      Other commands                                        0                   
      Combine commands                                      0                   
      SHOW HISTORY command                                  0                   
      SAVE command                                          0                   
      COMMENT command                                       0                   
                                                                                
                                                                                
2.0 ASSIST MODE                                                                 
________________                                                                
                                                                                
  Assist mode sessions as:                                  % of Campus         
                                          % of Total     MELVYL MEDLINE         
                                     Assist Sessions           Sessions         
                                     _______________     ______________         
    Berkeley                                    0.0%               0.0%         
    Davis                                       0.0%               0.0%         
    Irvine                                      0.0%               0.0%         
    Los Angeles                                 0.0%               0.0%         
    Riverside                                   0.0%               0.0%         
    San Diego                                   0.0%               0.0%         
    San Francisco                               0.0%               0.0%         
    Santa Barbara                               0.0%               0.0%         
    Santa Cruz                                  0.0%               0.0%         
    Stanford                                    0.0%               0.0%         
    Other                                       0.0%               0.0%         
                                                                                
                                                             % of Group         
                                          % of Total     MELVYL MEDLINE         
                                     Assist Sessions           Sessions         
                                     _______________     ______________         
    Medical/Health/Life Sciences                0.0%               0.0%         
    All Other Libraries                         0.0%               0.0%         
    Remote                                      0.0%               0.0%         
                                                                                
                                                                                
  SEARCH information:                                                           
                                                                                
    Average number of searches completed per session      0.0                   
    Retrievals per search - average                       0.0                   
    Retrievals per search - median                        0.0                   
    Retrievals per search - standard deviation            0.0                   
    Percent of searches completed with 0 results          0.0%                  
                                                                                
                                                                                
  COMMANDS entered, by type, excluding errors:                                  
                                                               % of all         
                                                   Total       Commands         
                                              __________     __________         
    FIND                                               0           0.0%         
    DISPLAY (excluding automatic displays)             0           0.0%         
    BROWSE SU                                          0           0.0%         
    SELECT                                             0           0.0%         
    HELP                                               0           0.0%         
    SAVE                                               0           0.0%         
    ADD-ON (AND, OR)                                   0           0.0%         
    LOGON or LOGOFF                                    0           0.0%         
                                                                                
                                                                                
  FINDS completed:                                  RETRIEVALS PER NON-         
                          TOTAL    ZERO RESULTS    ZERO RESULT SEARCHES         
                  _____________  ______________  ______________________         
                           % of            % of                                 
                            all         all for                    Std.         
                     No.  FINDs     No.   Index  Median    Avg.    Dev.         
                  ______ ______  ______ _______  ______ _______ _______         
  By index:                                                                     
  PERSONAL AUTH        0   0.0%       0    0.0%       0     0.0     0.0         
  TITLE WORD           0   0.0%       0    0.0%       0     0.0     0.0         
  KEYWORD              0   0.0%       0    0.0%       0     0.0     0.0         
  DATE                 0   0.0%       0    0.0%       0     0.0     0.0         
  LANGUAGE             0   0.0%       0    0.0%       0     0.0     0.0         
  EXACT SUBJECT        0   0.0%       0    0.0%       0     0.0     0.0         
                                                                                
  By number of indexes:                                                         
  Multiple             0   0.0%       0    0.0%       0     0.0     0.0         
  Single               0   0.0%       0    0.0%       0     0.0     0.0         
                                                                                
                                                                                
  LIMITS:                                                                       
                                                                                
    Number of times limits (bit strings) used:              0                   
                                                                                
    Use by bit string (percentage):                                             
      Current year                                       0.0%                   
      English Language                                   0.0%                   
      XS Aged                                            0.0%                   
      XS Animal                                          0.0%                   
      XS Case Report                                     0.0%                   
      XS Child                                           0.0%                   
      XS Female                                          0.0%                   
      XS Human                                           0.0%                   
      XS Male                                            0.0%                   
      PT Review                                          0.0%                   
                                                                                
                                                                                
  BOOLEAN:                                                                      
                                                                                
    Number of searches with Booleans:                       0                   
      (FIND, BROWSE, SELECT, ADD-ON)                                            
                                                                                
    Percentage of ANDs                                   0.0%                   
    Percentage of ORs                                    0.0%                   
                                                                                
                                                                                
  DISPLAY commands, by type, excluding automatic displays:                      
                                                                                
    REVIEW                                               0.0%                   
    BRIEF                                                0.0%                   
    LONG                                                 0.0%                   
    TITLE/SUBJECT                                        0.0%                   
                                                                                
                                                                                
3.0 COMMAND MODE                                                                
________________                                                                
                                                                                
  SEARCH information:                                                           
                                                                                
    Average number of searches completed per session      3.0                   
    Retrievals per search - average                     645.1                   
    Retrievals per search - median                        9.0                   
    Retrievals per search - standard deviation         5866.2                   
    Percent of searches completed with 0 results         21.8%                  
                                                                                
    Percent of searches entered that are long             0.4%                  
    Percent of long searches completed                   55.2%                  
                                                                                
  COMMANDS entered, by type, excluding errors:                                  
                                                               % of all         
                                                   Total       Commands         
                                              __________     __________         
    FIND                                         198,285          25.2%         
    DISPLAY (excluding automatic displays)       290,815          37.0%         
    BROWSE                                         4,172           0.5%         
    SELECT                                         2,520           0.3%         
    HELP                                          10,278           1.3%         
    EXPLAIN                                        7,869           1.0%         
    SAVE                                          52,525           6.7%         
    SET/RESET                                     36,841           4.7%         
    SHOW                                           2,904           0.4%         
    ADD-ON (AND, OR, AND NOT)                     46,132           5.9%         
    LOGON or LOGOFF                               97,748          12.4%         
    COMMENT                                            5           0.0%         
    OTHER                                         35,343           4.5%         
                                                                                
                                                                                
  FINDS completed:                                  RETRIEVALS PER NON-         
                          TOTAL    ZERO RESULTS    ZERO RESULT SEARCHES         
                _______________  ______________  ______________________         
                           % of            % of                                 
                            all         all for                    Std.         
                     No.  FINDs     No.   Index  Median    Avg.    Dev.         
                ________ ______  ______ _______  ______ _______ _______         
  By index:                                                                     
  PERSONAL AUTH   76,246  28.1%  15,647   20.5%      11   103.4  1339.0         
  TITLE WORD      26,511   9.8%   8,250   31.1%       9   387.6  4726.8         
  EXACT TITLE      2,154   0.8%     999   46.4%       1    35.1   228.4         
  JOURNAL         11,531   4.2%   3,682   31.9%     121  1839.8  5457.7         
  EXACT JOURNAL    3,608   1.3%   1,212   33.6%     255  1882.7  4856.9         
  PERIODICAL           0   0.0%       0    0.0%       0     0.0     0.0         
  EXACT PE             0   0.0%       0    0.0%       0     0.0     0.0         
  KEYWORD        108,880  40.1%  21,433   19.7%      29  1110.9  8456.4         
  SUBJECT WORD       521   0.2%     253   48.6%     205  2543.8 12283.3         
  SUBJECT         11,486   4.2%   4,833   42.1%     209  2340.2  8387.0         
  MAJOR SUBJECT      577   0.2%     123   21.3%     167  1506.6  4697.4         
  EXACT SUBJECT    3,302   1.2%     722   21.9%      96   975.0  3567.9         
  MAJOR XS           554   0.2%     134   24.2%     114   849.9  2297.3         
  EXPLODE XS       1,396   0.5%     217   15.5%     123  4422.1 19167.0         
  EXPLODE MAJOR      239   0.1%      37   15.5%     104  2447.5  7794.2         
  TREE NUMBER         23   0.0%       2    8.7%   8,180 78142.2  152820         
  MAJOR TREE NUMBER    0   0.0%       0    0.0%       0     0.0     0.0         
  DATE             9,125   3.4%   1,721   18.9%      12   209.2  1626.2         
  LANGUAGE         7,731   2.8%     527    6.8%      66   606.1     0.0         
  PUB TYPE         4,140   1.5%     371    9.0%      32   239.7  1117.2         
  Other indexes    3,055   1.1%     455   14.9%       1   341.4  4188.9         
                                                                                
  By number of indexes:                                                         
  Multiple        73,682  30.3%  16,817   22.8%      12   344.6  4553.4         
  Single         169,883  69.7%  36,570   21.5%      29  1062.4  7459.7         
                                                                                
                                                                                
  BROWSES completed:                                RETRIEVALS PER NON-         
                          TOTAL    ZERO RESULTS    ZERO RESULT SEARCHES         
                  _____________  ______________  ______________________         
                           % of            % of                                 
                            all         all for                    Std.         
                     No.   BROs     No.   Index  Median    Avg.    Dev.         
                  ______ ______  ______ _______  ______ _______ _______         
  By index:                                                                     
  PERSONAL AUTH      194   4.7%      29   14.9%       4    23.4    72.4         
  JOURNAL            502  12.1%     110   21.9%       2    92.9   287.1         
  EXACT JOURNAL       99   2.4%      19   19.2%       1     3.3     7.3         
  SUBJECT          3,169  76.5%     606   19.1%       2    26.0   234.4         
  EXACT SUBJECT      125   3.0%      37   29.6%       1     1.1     1.1         
  TREE NUMBER         53   1.3%       4    7.5%       1   117.2   347.7         
                                                                                
  By number of indexes:                                                         
  Multiple             2   0.0%       2    100%       0     0.0     0.0         
  Single           4,138  99.9%     801   19.4%       2    33.8   233.4         
                                                                                
                                                                                
  LIMITS:                                                                       
                                                                                
    Number of times limits (bit strings) used:         14,799                   
                                                                                
    Use by bit string (percentage):                                             
      Current year minus 5                               0.0%                   
      Current year minus 4                               0.0%                   
      Current year minus 3                               1.9%                   
      Current year minus 2                               0.4%                   
      Current year minus 1                               0.3%                   
      Current year                                       0.6%                   
      English Language                                  53.3%                   
      French Language                                    0.1%                   
      Japanese Language                                  0.0%                   
      German Language                                    0.0%                   
      Russian Language                                   0.0%                   
      XS Abstract                                        0.9%                   
      XS Adolescence                                     0.1%                   
      XS Adult                                           0.4%                   
      XS Aged                                            0.4%                   
      XS Animal                                          0.2%                   
      XS Case Report                                     0.0%                   
      XS Child                                           0.7%                   
      XS Comparative Studies                             0.1%                   
      XS English Abstract                                0.0%                   
      XS Female                                          0.4%                   
      XS Human                                           9.1%                   
      XS Infant                                          0.0%                   
      XS Infant, Newborn                                 0.1%                   
      XS Male                                            0.0%                   
      XS Mice                                            0.0%                   
      XS Middle Age                                      0.1%                   
      XS Rats                                            0.1%                   
      XS Support Non-U.S. Govt                           0.0%                   
      XS Support U.S. Govt, Non-P.H.S.                   0.0%                   
      XS Support U.S. Govt, P.H.S.                       0.0%                   
      PT Review                                         25.8%                   
      PT Journal Article                                 0.3%                   
      SUBSET AIM                                         4.3%                   
      SUBSET Indexing priority 1,2                       0.0%                   
      SUBSET Nursing journals                            0.3%                   
      SUBSET Dental journals                             0.0%                   
      SUBSET Cancer core journals                        0.0%                   
                                                                                
  BOOLEAN:                                                                      
                                                                                
    Number of searches with Booleans:                  84,859                   
      (FIND, BROWSE, SELECT, ADD-ON)                                            
                                                                                
    Percentage of ANDs                                  95.5%                   
    Percentage of ORs                                    2.8%                   
    Percentage of AND NOTs                               1.7%                   
                                                                                
                                                                                
  DISPLAY commands, by type, excluding automatic displays:                      
                                                                                
    REVIEW                                               1.6%                   
    BRIEF                                               64.2%                   
    LONG                                                 0.8%                   
    MEDLINE                                              1.1%                   
    FIELDS                                               2.4%                   
    PERIODICALS                                          0.0%                   
    BROWSE REVIEW                                        1.0%                   
    BROWSE LONG                                          0.4%                   
    BROWSE FIELDS                                        0.1%                   
    BROWSE MEDLINE                                       0.0%                   
    Other                                               28.3%                   
                                                                                
4.0  Error, EXPLAIN, HELP statistics (ASSIST & COMMAND)                         
_______________________________________________________                         
                                                                                
  Percent of commands that contained errors             10.3%                   
                                                                                
  Ten most frequent errors:                                                     
    1. NS command - no next screen                      37.4%                   
    2. First word of command is invalid                 27.8%                   
    3. FIND command with invalid index name              6.8%                   
    4. DISPLAY command contains invalid word             3.9%                   
    5. PS command - no previous screen                   2.9%                   
    6. Valid command at an inappropriate time            2.0%                   
    7. Add-on search with invalid index name             1.8%                   
    8. Search term missing from search command           1.6%                   
    9. NS of SHOW/EXP command-no next screen             1.2%                   
   10. DISPLAY command-record numbers too large          1.1%                   
   11. All others                                       13.4%                   
                                                                                
                                                                                
  Ten most frequent EXPLAIN requests:                                           
    1. LOCATE (article dbs w/o monographs)              16.4%                   
    2. BOOKS DATABASE                                   12.8%                   
    3. FIND                                              8.3%                   
    4. MEDLINE BACKFILES                                 7.7%                   
    5. Unrecognized term                                 5.5%                   
    6. COMMANDS                                          5.5%                   
    7. ADD-ON SEARCH                                     4.0%                   
    8. DISPLAY                                           3.9%                   
    9. INDEXES                                           3.3%                   
   10. DATABASES                                         2.9%                   
   11. All others                                       29.6%                   
                                                                                
                                                                                
  Ten most frequent HELP situations:                                            
    1. Command mode selected from Welcome               19.5%                   
    2. First word of command is invalid                 15.8%                   
    3. DISPLAY command-first of >1 screen                7.2%                   
    4. FIND command with invalid index name              6.7%                   
    5. FIND command retrieves >1 book                    4.9%                   
    6. DISPLAY command - middle of >1 screen             4.4%                   
    7. NS command - no next screen                       3.7%                   
    8. DISPLAY command - last of >1 screen               3.1%                   
    9. NS of SHOW/EXP command-no next screen             2.5%                   
   10. FIND command with zero results                    2.4%                   
   11. All others                                       29.6%                   
                                                                                
                                                                                
  Ten most frequent SHOW requests:                                              
    1. HISTORY                                          58.0%                   
    2. SEARCH                                           25.4%                   
    3. MAIL STATUS                                       6.7%                   
    4. SETTINGS                                          3.3%                   
    5. MEDLINE GLOSSARY                                  2.3%                   
    6. MAIL SETTINGS                                     1.0%                   
    7. MEDLINE NEWS                                      0.5%                   
    8. MEDLINE STATISTICS                                0.4%                   
    9. MEDLINE LOADING STATISTICS                        0.3%                   
   10. DISPLAY                                           0.2%                   
   11. All others                                        1.8%