extending through 1974 where possible. Data 

 which appeared in Science huiicalors — 19 72 for 

 earlier years are repeated here to encourage 

 longitudinal comparisons and to make it un- 

 necessary to refer to the previous report. Most 

 of the indicators are presented in graphical form 

 and are numbered to correspond with the 

 numerical data tables in the Appendix. Each of 

 the chapters is introduced by an "Indicator 

 Highlights" section which briefly summarizes 

 the major indices of that chapter. It should be 

 noted that these highlights often omit important 

 caveats and discussion contained in the text 

 itself. The original data sources, many of which 

 are publications of the Division of Science 

 Resources Studies, National Science Founda- 

 tion, are indicated throughout the report. Staff 



of the Division also took part in the development 

 of charts and text. 



The challenge faced in creating and using 

 indicators of complex social systems such as 

 science and technology is substantial, and the 

 present efforts to assess U.S. science are still 

 only in the early stages of maturity. Apprecia- 

 tion is due to the Social Science Research Council 

 which, with NSF support, convened a seminar in 

 1974 on science indicators and which has 

 recently established a Subcommittee on Science 

 Indicators. The reports to follow in this series 

 will aim to sharpen concepts, refine their 

 treatment, and seek new measures of the state of 

 science. It is hoped that all those interested in 

 science indicators will participate in the search. 



