Acceptability and Extensibility of Typeform Indicators in UEB and in NUBS (4/17/2012 Draft)

Note that an accompanying article discusses various drawbacks to the use of typeform indicators in braille transcriptions along with possible alternatives.

Table of Contents

• Executive Summary
• References
• 1. Introduction
• 2. Acceptability: UEB versus NUBS
• 3. Extensibility: UEB versus NUBS
• 4. Typeform indicator construction in UEB and NUBS
  • 4.1 Similarities in typeform indicator construction in UEB and NUBS
  • 4.2 Differences in typeform indicator construction in UEB and NUBS
    • 4.2.1 UEB typeform indicator construction
    • 4.2.2 NUBS typeform indicator construction
• 5. Tables of UEB and NUBS typeform indicators
  • 5.1 Table of UEB and NUBS explicit typeform indicators
  • 5.2 Tables of UEB and NUBS transcriber-assigned typeform indicators
• Conclusion

"The mission of the Braille Authority of North America (BANA) [http://www.brailleauthority.org] is to assure literacy for tactile readers." In so doing "BANA considers the effects of its decisions on ... acceptability to readers."

BANA has recently published a three-part article [http://www.brailleauthority.org/article/evolution_of_braille-full.pdf] that describes certain deficiencies in its current braille codes and proposes adopting of a new braille system.

Code building is a more challenging task than it first appears; even simple "fixes" become complicated given the complexities of our current codes. The literary braille code was not designed to be "extensible” – that is, there are no clear and specific rules for building and changing symbols in a logical fashion. Right now, every proposed change to the braille code has to be considered individually in an ad hoc fashion. ...

The committee recommends that BANA adopt a system such as UEB or NUBS that was designed to be extendible, flexible, and consistent.

The purpose of the present paper is to evaluate UEB and NUBS typeform indicators with respect to BANA's criteria of acceptability and extensibility.

Although it is difficult to measure acceptability it appears plausible that the UEB typeform indicators would be less acceptable than the corresponding NUBS indicators because of the use of braille cells with unrelated meanings in other contexts and because they would be harder to remember. All the UEB start indicators terminate with braille cells used as punctuation marks and contractions in other contexts while all the NUBS start indicators terminate with braille cells only ever used as symbol prefixes. Also all of the transcriber-assigned UEB indicators incorporate the braille cell used elsewhere as a number sign.

As far as entensibility, both systems achieve extensibility via transcriber-assigned typeform indicators. UEB specifies five sets of typeform indicators that can be transcriber-assigned while NUBS provides for the construction of any number of sets of typeform indicators that can be transcriber-assigned.

In summary, it appears that the design of the NUBS typeform indicators achieves greater acceptability than the design of the UEB typeform indicators. However, both systems seem to meet BANA's extensibility criteria with respect to the particular issue of typeform indicators.

The UEB rules are based on The Rules of Unified English Braille, June 2010 (UEB Rulebook) which can be obtained from the International Council on English Braille (ICEB) Project Page. [http://www.iceb.org/ueb.html]

The NUBS rules based on the full NUBS [http://www.braille2000.com/brl2000/nubs2.htm] documentation.

3. Extensibility: UEB versus NUBS

BANA wants its braille codes or systems to be extensible so as to be able to accommodate future changes. Both UEB and NUBS provide an extensibility mechanism for typeforms based on the use of transcriber-assigned typeform indicators. NUBS is slightly more extensible than UEB in that it allows a transcriber to construct any number of additional typeform indicator sets consistent with its rules for symbol construction while UEB provides only five explicitly defined sets of typeform indicators which can be transcriber-assigned.

4.1 Similarities in typeform indicator construction in UEB and NUBS

Both braille systems provide sets of four indicators for specifying a given typeform as shown in Table 1 for the italic typeform indicators. Each set includes three start indicators to be used to indicate the typeform of a single character, of a single word or shorter sequence of characters, and of a passage, respectively. There is one terminator indicator to terminate the sequence and passage indicators. (The single character indicator doesn't need to be terminated because its scope is implicit. The word indicator is terminated automatically by the end of a word.)

4.2 Differences in typeform indicator construction in UEB and NUBS

All UEB typeform indicators consist of a prefix and a root. The NUBS start typeform indicators are simple prefixes while the NUBS typeform termination indicators consist of a prefix and a root.

Both the UEB and NUBS typeform indicators terminate in a single cell that designates the extent of the effect of the indicator. The interpretation of the UEB extent designators is context-sensitive in that these same cells are used as punctuation marks or contractions in other contexts while this is not the case for NUBS. The UEB extent designators are not based on mnemonics wheareas the NUBS extent designators are based on a simple mnemonic system.

4.2.1 UEB typeform indicator construction

All typeform indicators in UEB consist of two parts: a single- or multi-cell prefix that designates the typeform and a (necessarily single-cell) root that designates or determines its extent. All nine sets of typeform indicators use the same four root cells. Note that these root cells have unrelated meanings in other contexts. The extent designator for a symbol, dots-23, is also used as a semicolon; the extent designator for a word, dot-3, is also used as a comma; the extent designator for a passage dots-2356, is also the contraction for were.

Because these indicators terminate with a root cell, any number of UEB typeform indicators can be used in sequence—e.g. to indicate bold plus italics—without ambiguity. The UEB Rulebook recommends that in the case of a sequence of typeform start indicators requiring terminators that their respective terminators be nested, i.e., be in reverse order from their start indicators.

UEB provides four sets of explicit typeform indicators shown in Table 2 and five sets of user-assigned typeform indicators shown in Tables 3 and 4.

4.2.2 NUBS typeform indicator construction

All typeform indicators in NUBS consist of two parts: a single- or multi-cell leading portion that designates the typeform and a final cell that designates its extent. Explicit typeform start indicators in NUBS are a multi-cell prefix. The braille symbol for a typeform passage start indicator repeats the typeform designator twice and terminates with the same extent designator as does the corresponding symbol indicator.

Even though these start indicators do not end with a root cell, they can be used in sequence without ambiguity because the cells used to designate the extents are not used in the typeform designators. This will also hold true for NUBS transcriber-defined typeform symbols as long as they are constructed in accord with this design.

Typeform terminators in NUBS use a prefix-root construction like the UEB ones. Here the prefix used to designate the typeform is the same as the typeform designator for the corresponding typeform start indicators and the root is the same as the UEB typeform terminator root, dot-3.

NUBS provides three sets of explicit typeform indicators shown in Table 2 and allows the transcriber to construct any number of additional typeform indicators consistent with the the NUBS system for braille symbols. Five possible NUBS transcriber-defined typeform indicators are shown in Tables 3 and 4.