The Evolution and Evaluation of Pie Menu Interactions in Text Input

Abstract: Pie menus, also known as radial menus, have been studied in the realm of user interfaces. Various applications of pie menus have been explored, with research focusing on their usage in diverse contexts and their impact on user behaviour. As interactive devices such as touch screen mobiles, virtual reality, mixed reality, and touch-based physical products rapidly permeate into the users’ hands, they are driving the demand for studies in multi-model interactions. The pie menu is a promising UI pattern that offers various selection options within a constrained radius. Mostly, the interaction requires human action like click, swipe or steer gestures, and efforts like visual search, decision time. Despite the efforts by different research groups to derive an effective model on human performance, we observed that the derived models on Pie menu are studied independently, but all models are based on Fitts’ law and its extension in text input methods. We conducted a comprehensive literature review of publications from ACM, IEEE, HFES, and few others focusing on the evolutions of Pie menus and their derived models. Our qualitative study examined three aspects: application of pie menu in the context of text input, touch mobile interfaces, models applied or derived in these studies. Through a mixed-method analysis, we evaluated these aspects and narrowed our focus to 38 papers that specifically address text input methods and human performance. Our findings revealed that the performance of pie menus varied significantly across different use cases. Some studies reported that the northwest side of the menus was harder to access, while others suggested that pie menus were theoretically easy to learn but performed less effectively than square menus. However, in the context of text input, pie menus outperformed conventional keyboards. We propose that future research should aim to develop a standard methodology for testing pie menus that can be generalized across different contexts with minimal modifications. The results of this review will provide valuable insights for researchers and designers working on Pie menu interactions, helping them understand previous research, identify gaps, and determine future directions.

Keywords: Pie Menu, Radial Menu, Fitts' Law, Steering Law, Performance, Hierarchical, Text Entry, Soft Keyboard, Swarachakra, Tunnel Law, Review

DOI: 10.54941/ahfe1005364

Cite this paper:

​