Requirements

This page lists requirements for abbreviations that are included with Lesshand. These requirements are enforced by automated tests.

In the remainder of this document, we use the word source for the word or phrase being abbreviated, and target for the abbreviated version.

R001: Typeable

Lesshand should be typeable. It's the 21st century, after all! Thus, abbreviations must not introduce characters that do not appear on ANSI US QWERTY keyboards.

R002: Words

No abbreviation should target an existing word. We check this against the most common 4000 words from the COCA corpus.

R003: Effort

An abbreviation should save the user at least 5 effort, unless it is for one of the 128 most common words in which case it should save at least 1.

Example

"s" is not a good abbreviation for "sad", because it doesn't save much effort.

"n" is an acceptable abbreviation for "no". "no" is exceptionally common, so this abbreviation saves considerable effort by virtue of being used so frequently.

R004: Valid source

The source of an abbreviation may only contain the characters A-z, ', and .

R005: Valid target

The target of an abbreviation may only contain the characters A-z, 0-9, ', , ,, and ;.

R006: Unique

No two abbreviations may share a target.

R007: Memorable

Abbreviations must have a memorability of at least 5, unless the abbreviation is for one of the 128 most common words and is only one character (e.g., for --> f, the --> l).

R008: Uniquely memorable

An abbreviation must not have a higher memorability for a common word other than its source.

R009: Not known to be ambiguous

No abbreviations should have the following highly ambiguous targets:

• ar: "another", "around"
• cm: "come", "came"
• ev: "electric vehicle", "even", "ever", "every"
• mt: "might", "most", "must"
• se: "sea", "see", "set", "she"
• sm: "same", "some"
• te: "the", "their", "there"
• th: "the", "that", "their", "this"
• tr: "their", "they're"
• wh: "with", "what", "when", "where", "why"
• wn: "wane", "won", "when"
• wr: "were", "where"
• wt: "wait", "what"
• yr: "year", "your"

This list is simply based on human judgment.

R010: Unambiguous

An abbreviation should have an ambiguity of less than 1100, unless it is an abbreviation for one of the 128 most common words.

Example

"se" is an ambiguous (bad) abbreviation, because it could stand for "sea", "see", "set", "she", etc. It has an ambiguity of 6562.