<?xml version="1.0" standalone="yes"?>
<Paper uid="H01-1004">
  <Title>Amount of Information Presented in a Complex List: Effects on User Performance</Title>
  <Section position="3" start_page="0" end_page="0" type="intro">
    <SectionTitle>
1. INTRODUCTION
</SectionTitle>
    <Paragraph position="0"> AT&amp;T Communicator is a state-of-the-art spoken dialogue system that allows the end-user to select and reserve various travel related resources, in particular, airfare, hotel, and rental cars [2]. One of its most challenging dialog modules is that for presenting information that allows the user to select a desired air travel itinerary. While selecting between multiple possible itineraries in a visual domain is a relatively simple task because most of the selection criteria are listed in a single scrollable page, the same task is likely to have a much higher cognitive load in an audio-only domain [1, 3]. The selection criteria for each candidate flight must be presented to the user serially, leading to higher cognitive demands that could result in errors in itinerary selection.</Paragraph>
    <Paragraph position="1"> A sample AT&amp;T Communicator dialog with the prototype used in this experiment, showing the outbound flight only, follows.</Paragraph>
    <Paragraph position="2"> System: Hello, this is AT&amp;T Communicator.</Paragraph>
    <Paragraph position="3"> How may I help with your travel plans? User: Yeah, I'd like to fly from Newark to San Francisco.</Paragraph>
    <Paragraph position="4"> System: OK, a flight from Newark, New Jersey to San Francisco, California. And will this be a round trip? User: Yes, and I need to arrive in San Francisco by 4 PM on November 22nd.</Paragraph>
    <Paragraph position="5"> System: I found five outbound United Airlines flights.</Paragraph>
    <Paragraph position="6"> Option 1 is flight number 635. It has one stop; it departs at 10:15 A.M. and arrives at 2:42 P.M.</Paragraph>
    <Paragraph position="7"> &lt;pause&gt; Option 2 is flight number 7535. It has one stop; It departs at 12:20 P.M., and arrives at 4:37 P.M.</Paragraph>
    <Paragraph position="8"> &lt;pause&gt; Option 3 is flight number 837. It' s a non-stop flight; it departs at 2:00 P.M. and arrives at 5:01 P.M. &lt;pause&gt; Would you like to hold any of these flights? User: I guess I'll take option one.</Paragraph>
    <Paragraph position="9"> System: Got it.</Paragraph>
    <Paragraph position="10"> Note that the second to the last system utterance, in which a set of itineraries are presented to the user for selection, is by far the longest system utterance in the dialog. This utterance includes a complex list of information. Unlike a more simple list, each list item (option) contains a number of sub-items, for example flight number, number of stops, etc. In early dialog evaluations of the Communicator system, the selection of a single itinerary from such a complex list of flights was a source of substantial usability problems; users frequently became frustrated. In fact, many users dropped out of the dialog before successfully selecting an itinerary.</Paragraph>
    <Paragraph position="11"> This paper describes an experiment in which we vary the amount and structure of information presented about available itineraries. We predict that the amount and structure of information presented affects the ability of users to successfully select the optimal itinerary within a set, and influences subjective measures such as user satisfaction.</Paragraph>
  </Section>
class="xml-element"></Paper>