Command representation (2)
Abbreviations general - if users must type commands, they should be able to use abbreviations instead of typing complete commands. If it is appropriate to the task to provide command abbreviations, these abbreviations should be obvious to the user, easily remembered, and facilitate command input. [NOTE if the command input is an abbreviation and system constrains allow, the ‘whole’ command name may be displayed prior to, or simultaneous with, execution (especially during learning the CL] abbreviations rules - (a) if command names are shortened, they should be shortened using as simple a rule as possible; that rule should apply to all commands and those arguments that can be abbreviated; (b) if the task requires the user to generate and remember commands, simple truncation should be used to shorten commands. [EXAMPLE (a) truncation: pr for print; dropping of vowels: prnt for print] [EXAMPLE (b) to drop off characters beyond those necessary to keep the command unique (e.g. q for quit; qui for quit and que for query)]