A Bliss Writing System

  • Palatuwa Gamage Rajitha Hasith Nandadasa

Student thesis: Master's ThesisMaster of Philosophy


Being able to communicate in the natural environment and sufficiently meet daily communication needs is the essence of communication. The majority of the population in the world does not think about the mechanics required to communicate effectively. However, there is a significant number of people who experience difficulties in communication due to speech and/or cognitive impairments. Alternative methods of communication can be used to help people with disabilities to maximise the competence of communication. These alternative methods are referred to as Augmentative and Alternative Communication (AAC).

Blissymbolics (typically shortened to “Bliss”) is an ideographic written language that was developed by Charles K. Bliss for international communication in 1949, but currently Bliss is used by pre-literate nonspeaking children and adults as a means to communicate. In the past and present, AAC access methods that use Blissymbolics have been mainly developed by the teacher or the therapist rather than the Bliss user. Bliss users typically access Bliss from a predefined chart, that is configured by the teacher/therapist to form sentences, which would then be voiced by a listener or output as speech using a high-tech AAC device. Bliss has mainly been used as a symbol set rather than a written language. Bliss users have never been given access to the full 1400+ Bliss-character set which would allow the Bliss users to write in Blissymbolics rather than access Bliss as a symbol set.

To address this the researcher developed a set of three input methods for Bliss-characters which gives the Bliss user access to the full Bliss-character set:

1. An input method based on the Bliss-alphabet
2. An input method based on glyph elements (strokes) used in Bliss-characters
3. A hybrid input method based on both of these

The Bliss-alphabet-based input method allows a Bliss user to access Bliss-characters by how the characters are categorised by the Bliss-alphabet shape. This allows the Bliss user to input a Bliss-alphabet shape and access Bliss-characters that belong to that letter of the Bliss-alphabet.

The stroke-based input method for Bliss allows a user to access Bliss-characters using the basic shapes (similar to strokes in Chinese writing) that have been used to form these Bliss-characters. After analysing how each Bliss-character is formed using these shapes, the researcher implemented an input method which allows a Bliss user to type multiple Bliss-alphabet shapes and access all the Bliss-characters that are formed with the typed Bliss-alphabet shapes.

The hybrid-based input method is a combination of both the Bliss alphabet-based input method and the Bliss stroke-based input method. In the hybrid-based input method, Bliss-characters are accessed using both Bliss alphabet-based and stroke-based input methods; when user type the first Bliss-alphabet shape, the Bliss-characters are retrieved using the Bliss alphabet-based input method, after which Bliss-characters are retrieved using the Bliss stroke-based input method.

The researcher ran two user studies with participants with various physical and speech impairments who use different AAC systems and access methods. The first study was conducted with seven participants in which they evaluated the Bliss writing system. The system log data from study 1 led into the implementation of the Bliss hybrid-based input method.

Study 2 was conducted with one participant who has some Bliss knowledge. The purpose of the study was to evaluate the Bliss hybrid-based input method and to compare the three Bliss-character input methods in terms of the speed of writing using each Bliss-character input method.

The results from study 2 show that the Bliss hybrid-based input method is faster than the Bliss alphabet-based and stroke-based input methods in terms of writing in Blissymbolics.
Date of Award2021
Original languageEnglish
SupervisorAnnalu Waller (Supervisor) & Alison Pease (Supervisor)


  • Bliss
  • communication
  • Blissymbols
  • Input methods
  • Augmentative and Alternative Communication

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