Learning items
Code
No chapter association
ConceptBinary combinations
Each independent two-state position doubles the number of possible patterns.
ConceptCommunication code
A code maps agreed signals to meanings that a receiver can recover.
ConceptMessage boundaries
A receiver needs to identify where units of a message begin and end.
ConceptVariable-length code
A coding scheme can assign different numbers of symbols to different characters.
VocabularyBinary state
A representation uses two distinguishable possibilities for each position.
VocabularySix-dot braille cell
A traditional braille cell has six positions that can each be raised or unraised.
