Documentation and Training Productivity Benchmarks
http://www.ingentaconnect.com/content/stc/tc/2003/00000050/00000004/art00009
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  peer-reviewed

Barr, John P. 'Jack' and Stephanie Rosenbaum
Technical Communication Online
2003

Abstract:

Investigates how computer-industry companies create end-user documentation and training materials, and how they measure productivity. Describes results of interviews of eleven managers of publications or training departments.