Study on Voice Controlled Computing

    This paper summarizes a research project studying some of the issues involved in controlling a computer by speaking to it in a human language.  I did this study my Senior year as a computer science major at Bob Jones University under the direction of Mr. Dan Wooster.
    In the original plan for the project, the software I was going to develop was to be integrated with the operating system.  The computer would accept input from either the keyboard or a speech recognition unit.  It would then determine whether the input was to be fed directly into an application or translated into a command for the operating system to perform.  The figure below illustrates this plan.

    Part way through the semester, it became obvious that the project was far too big to be done in a semester at the undergrad level.  So I scaled it back and decided to simply write a Linux shell that would take English sentences and execute the intended operating system command.  That is a much more reasonable short-term goal, but still involves a great deal of complexity.  First, the shell must make sense of the sentence, then it must match that meaning to a shell command or application.
    That kind of "understanding" in a piece of software pushes us into the realm of artificial intelligence. To write these "smart" pieces of the project, I chose to use PROLOG, following Dr. Ray C. Dougherty's work which he presents in Natural Language Computing: An English Generative Grammar in Prolog.  Dr. Dougherty first explains the use of PROLOG, which I attempt to summarize later in this report.  But his background is in linguistics, and that is the area in which his book most helpful.  He discusses the creation of a grammar in PROLOG, after which I have modeled a simple grammar for this project.  Following Dr. Dougherty's method I wrote a seperate lexicon of the words that will be recognized by the shell.  The lexicon I include here is very small and useful only for demonstration purposes.  Large lexicons should not be written as PROLOG facts, for reasons I explain later.
    The grammar I wrote successfully tells whether a sentence of the form it recognizes is grammatical.  But it does not label the parts of the sentence structure to help a semantic analysis unit attach meaning to the sentence.  One of Dr. Dougherty's example programs does output the structure through the use of lots of parentheses.  That may be the best one can hope for.

For more on PROLOG, this study, and suggestions for future research,see the outline of this report. For more information from a linguist's perspective, read:

Dougherty,Ray C.  Natural Language Computing:An English Generative
        Grammar in Prolog. 1994, Hillsdale, New Jersey,  Lawrence
        Erlbaum Associates.