Lightning Bug and the Lightning

Richard Wilhelm

Terminology in ASTM Standards

In an 1888 letter to George Bainton, Mark Twain wrote that "the difference between the almost right word and the right word is really a large matter - it's the difference between the lightning bug and the lightning."

Just a decade after Twain wrote this letter, ASTM was founded and its earliest members began probing the implications of Twain's statement, particularly with regard to how terms are defined in ASTM's standards. Throughout ASTM's existence, members have instinctively understood the importance of having terminology that accurately describes the objects and concepts that play important roles in ASTM standards.

"ASTM terminology needs to be written so that the reader who is a nontechnical specialist can understand the essential information about the term," says Vincent Diaz, president, Atlantic Thread and Supply Co. Inc., and a longtime ASTM member who has worked extensively on terminology for Committee D13 on Textiles as well as other ASTM committees.

The late Wayne Ellis, 1989-1990 chairman of the ASTM board of directors, was another ASTM member who had many ideas about terminology. In a 1983 SN article, Ellis wrote that a good definition combines:

  • A clearly understood concept;
  • A crisp statement of its meaning;
  • In words of few syllables, and
  • Without embellishment.

Diaz notes that ASTM terminology is very distinct from that of other dictionaries and compilations by its use of the discussions that often follow terms.

"These write-ups are able to provide a greater understanding to the reader of the term by using interpretative, elaborative and explanatory details that prevent any misunderstanding," says Diaz.

Diaz believes that the thoughtful development of terminology should be an important part of the standards writing process, even before the writing begins.

"When the author of a standard creates a list of key terms, which are carefully defined and interpreted, before starting to write a standard, there is less chance that the document will lead to either misunderstanding or confusion when the standard is sent out for ballot to the subcommittee and main committee," says Diaz.

Diaz thinks that the usefulness and clarity of terminology in ASTM standards is more important now than ever.

"Clear and well-defined terminology is of critical importance when the pace of technological change is moving at lightning speed," says Diaz.

Today, all of the terminology contained in ASTM standards can be found in the online ASTM Dictionary of Engineering Science and Technology, a powerful online tool that contains the thousands of terms currently defined in all of ASTM's standards, listings of all ASTM standards that reference each term, as well as the ASTM committee that developed the term. The dictionary also includes links from each standard designation referenced to the scope of that standard.

ASTM members have free access to the online terminology dictionary on their "MyASTM" page (see "MyTools"/"Additional Resources"). Nonmembers can learn more about the tool and subscribe at

No matter how members are able to view and use terminology in the future, one thing is certain: as long as ASTM committees exist, members such as Vincent Diaz who are devoted to terminology (in his SN article, Ellis called them "terminologists") will be busy sorting the lightning bugs from the lightning.

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