From: mdm@bnr.ca (Diane MacMartin)
Subject: Ottawa ACM/SIGCHI November Meeting
Organization: Bell-Northern Research, Ottawa
Date: Tue, 17 Nov 1992 17:27:19 GMT

*** Everyone is welcome to attend ***


                     Ottawa ACM/SIGCHI November Meeting
                     ==================================

                  Date:       Thursday, November 19, 1992

                  Time:       19:00 - 21:00

                  Place:      BNR Carling Auditorium 
                              (Pavillion Building, formerly Administration)
                              3500 Carling Ave., Nepean
                              Corner of Carling and Moodie

                  Speaker:    James H. Bradford
                              The Speech Interface Laboratory
                              Department of Computer Science
                              Brock University, St. Catharines, Ontario

                  Topic:      "How to wreck-a-nice-beach"
                                       ...or...
                              Combating Recognition Errors

                  Elections:  1992-1993 Elections will be Held (see below)


                              About the Talk
                              --------------

A number of recent papers on the design of speech interfaces have argued in
favour of short command sequences.  The argument usually proceeds as
follows: suppose that a given speech recognizer has a word recognition rate
of 95%.  The probability of recognizing a 10 word utterance without error
is about 60% (i.e.  0.9510).   In a more realistic setting with background
noise and speaker variability recognition rates often drop below 80%.  With
an 80% recognition rate, the probability of recognizing a 10 word utterance
without error is only 11%!  This, as well as the difficulties encountered
with command confirmation and error correction dialogues tends to support a
preference for short command sequences.

However, this talk presents a design methodology which favours processing
commands in larger aggregates called "command paragraphs."  The application
of command paragraphs dramatically increases the amount of locally
available contextual information.  Typically a paragraph consists of a
number of individual commands that when taken together, completely specify
how a task is to be performed.  Thus the grammar of the constituent
commands and knowledge about how the commands work together to achieve 
a task can be used to correct recognition errors made on a word-by-word
basis.

We developed a prototype which tests the paragraph approach with an
interface using a speaker-dependent discrete-word recognizer.  The
prototype itself controls a simulated robotic arm which manipulates various
objects in earth orbit.  The user can launch satellites, weld beams, etc.,
using only verbal commands.  Feedback is provided by a computer driven
animation.  

Initial experience with the prototype is very encouraging.  In one
demanding trial, a command paragraph specifying a weld on a free floating
beam contained 10 separate command sentences for a total of 43 words.  The
test was conducted in a noisy environment and the operator was suffering a
cold.  As a result there were 17 recognition errors.  A total of 16 errors
were corrected by grammatical analysis and the remaining error by analysis
of the task semantics.  Thus the interface was able to deduce the correctly
worded paragraph without recourse to correction dialogues.  This is in
contrast with the traditional approach which would have required 17
corrections on a word-by-word basis.

The use of longer rather than shorter command sequences as input to speech
interfaces represents a significant (and promising) departure from the
usual design paradigm.


                  Ottawa ACM/SIGCHI Elections  1992-1993
                  =======================================

Here's your opportunity to make a contribution to the Ottawa ACM/SIGCHI!
At our first meeting we'll be having our elections.  This organization is
run by active volunteer participation.  This is YOUR organization, and its
success depends on you!  Please consider participating in whatever capacity
you can contribute.  The positions for office are listed below.  Please note
that both director and assistant positions are open.  

If you are interested in running for a position but cannot attend our
November meeting, then contact Sonia Bot at 763-4992 or sdbot@bnr.ca
to have your name placed on the ballot.
   
Chair
-----
- Liason with ACM/SIGCHI
- Provides overall focus for Ottawa chapter
- Ensures co-ordination among the directorships
- Announces meetings and events

Program Director
----------------
- Contacts and arranges speakers for meetings
- Provides gifts for speakers

Facilities Director
-------------------
- Arranges rooms for meetings
- Provides refreshments for meetings

Publicity Director
------------------
- Newsletter publication

Treasury
--------
- Maintains financial state of chapter

Funding Director
----------------
- Raises funds from various patrons in the industry

Membership Director
-------------------
- Prime for membership drive
- Receives membership forms
- Maintains membership database

Assistants
----------
- Assist in any of the above categories according to choice


For further information contact:
-------------------------------

Sonia D. Bot              Scott McEwen              Tom D'Ippolito
(613)763-4992             (613)763-2552             (613)763-9515
email:  sdbot@bnr.ca      email:  mcewen@bnr.ca     email:  crtxd02@nt.com
Newsgroups: ott.events