Design of Conversation Interaction Between Users and Systems to Prevent Human Misunderstanding
Authors: Toru Nakata
Abstract: Human ability on thinking is considered as imperfect. Our logic is intuitive and not logically strict. Also, capacity of our memory is limited. We often fail to make correct judgement. Therefore, agents interacting with human users, which may be user interfaces of computer systems and instruction documents, should guide the users to avoid their logical defects. When a system accepts the order from a user, it questions to the user several times to clarify user’s demand. Such conversation should be designed with considerations on questioning style, order of questions, concreteness of question, and so on.This paper proposes three principles on questioning design.2. Principle of positive wording and avoiding negative conditioningEven though logical denial forms are often used in questioning sentences, they should not be used. In general, logical negative expressions hide what you really want to mean and state unimportant things instead. Instead of them, positive and explicit expression are proper for the interaction. For example, an instruction of "If not A, do X." has a disadvantage, since users have to pay effort to image what "not A" means. Explicit questioning, such as "If B or C, do X." is much clearer and reliable to guide the user’s thinking.3. Principle of independency from user’s memoryThe question should be answered by a user without remembering things in the past. One of typical bad questions is to inquire the experience memory of user’s actions. For example, "If you have put salt and sugar in, the operation is completed." Memory is unstable, and actions are not physical objects. So, remembering action experiences are rather difficult for users. The user’s answer might be incorrect. The system should inquire on evidence not memory like "Put salt and sugar in. Then, taste the object to check its completeness." 4. Principle of elimination of logical dependencyA conversation should go smoothly without stepping back, but sometimes it happens due to logical dependencies among the questions. Suppose a situation as follows. The first question is "Which do you like A or B?" Then, the second question is "A has an option X. Do you want it?" The user never finds the possibility of X when he selected B at first. Or the user will cancel his choice of B to step back the first question. It wastes user’s effort and time.An unsophisticated solution is to flatten all questions into a list of alternatives (disjunctive normal form, DNF) like "There are three alternatives: A, A with X, or B." But, in general, DNS becomes a too long list for practical use.Another solution is to reform the order of the question in respect to importance. If Option X is the most important, it should be confirmed first. The system should ask a question on user’s demand of X at the first question.The proper reform is elimination of logical dependency. If Option B can have X too, the order of the questions does not constrain the conversation.
Keywords: human error, human computer interaction, interaction design, user interface, education
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