SIZE OF CODE ALPHABET AND DECODING,

Abstract

One experiment was conducted to determine the effect of size of code alphabet on decoding. An original message consisting of the first 13 letters of the alphabet was generated by a zero-memory source with a (first-order) redundancy of approximately 14%. This message was encoded with either a binary, ternary, quaternary, or septenary code. There was a different group of subjects for each code, and their task was to decode back into the original 13 letters as rapidly and as accurately as possible. The results showed that, over the four sessions of testing, performance (i.e., decoding) was most rapid with the septenary code and progressively slower as the size of the code alphabet decreased. Since information load per symbol increases but number of symbols per code word decreases as size of the coding alphabet increases, it would appear that the latter was the critical variable. In general, these results suggest that, as has been noted before, for optimum information processing one wants to maximize the number of bits per chunk; thus, within the limits of the present experiment, the larger the size of the code alphabet the better the performance. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1964
Accession Number
AD0605665

Entities

People

  • Bennet B. Murdock Jr.
  • Edina C. Oldham

Organizations

  • University of Vermont

Tags

DTIC Thesaurus Topics

  • Alphabets
  • Coding
  • Decoding
  • Information Processing
  • Message Decoding
  • Message Processing
  • Symbols

Readers

  • Radio communications and signal processing.