Evaluating Usability of Text and Speech as Input Methods for Natural Language Interfaces Using Gamification

Abstract: Today an increasing amount of systems make use of Natural Language Interfaces (NLIs), which make them easy and efficient to use. The purpose of this research was to gain an increased understanding of the usability of different input methods for NLIs. This was done by implementing two versions of a text-based game with an NLI, where one version used speech as input method and the other used text. Tests were then performed with users that all played both versions of the game and then evaluated them individually using the System Usability Scale. It was found that text was better as input method in all aspects. However, speech scored high when the users felt confident in their English proficiency, acknowledging the possibility of using speech as input method for NLIs.