Defining Ergonomics/Human Factors

The title International Encyclopedia of Ergonomics and Human Factors suggests that ergonomics and human factors are possibly two separate subject areas which are being covered. The conjunctive “and” would support this interpretation. If ergonomics and human factors are synonymous, why not just use one name? Several years ago, the main professional organization of this area in the United States decided to change its name by adding the term “ergonomics.” They also decided to add the conjunctive “and,” as opposed to separating the names by a dash or a slash, forms that are more frequently used to connotate synonymity. The society is now called the Human Factors and Ergonomics Society (HFES). If ergonomics and human factors are the same, then why not use a slash instead of the “and” and call it Human Factors/Ergonomics Society? And for that matter, why not call this encyclopedia, the International Encyclopedia of Ergonomics/Human Factors? It is difficult to pronounce a slash (in speech, it is omitted). Thus, persons unfamiliar with the field would probably find the slash version rather odd sounding, hearing a string of three words and not knowing if the second word is an adjective. Conjoining both ergonomics