An Experimental Evaluation of Grounding Strategies for Conversational Agents

Abstract: With the continuous development of technology, dialogue system’s technology penetrates into human’s life. Grounding also becomes more and more important for dialogue systems. It is important to choose a suitable grounding strategy in a conversational agent. Two grounding strategies are compared in this article, explicit feedback and implicit feedback. The explicit feedback in this article is different from interrogative explicit feedback. It has been modified to make a system says ”Ok, x” in response to utterance x. The aim of this paper is to compare two grounding strategies and to find out which one is better. Additionally, how users respond to false feedback is also the research question in this article. In order to draw a conclusion, a dialogue system was implemented. This article uses a mix of quantitative method and qualitative method. Questionnaires are used to investigate the subjective judgments of participants. Participants evaluated the dialogue system through questionnaires. In the questionnaire, users rate the system from two aspects, naturalness and ease. From June 8th to 14th, the system was officially available. The data were analyzed by t-test and the result was presented in this article with diagrams. Most participants mentioned that they prefer the system with explicit feedback in the evaluation. According to the average score, the system with explicit feedback in this paper is more natural and easier to communicate than the system with implicit feedback. However, there is no significant difference between these two grounding strategies according to the results of the T-test. This does not mean that there are no differences, but that such differences may not be obvious because of the little sample size. In addition, user’s response to the wrong feedback is summarized in this article. Four kinds of reactions are described in this article, hesitation, repetition, point out the wrong feedback and correction.