Charting Subtle Interaction in the HCI Literature

Abstract

Human-computer interaction is replete with ways of talking about qualities of interaction or interfaces, including if they are expressive, rich, fluid, or playful. An example of such a quality is subtle. While this word is frequently used in the literature, we lack a coherent account of what it means to be subtle, how to achieve subtleness in an interface, and what theoretical backing subtleness has. To create such an account, we analyze a sample of 55 publications that use the word subtle. We describe the variants of subtle interaction in the literature, including claimed benefits, empirical approaches, and ethical considerations. Not only does this create a basis for thinking about subtleness as a quality of interaction, it also works to show how to solidify varieties of quality in HCI. We conclude by outlining some open empirical and conceptual questions about subtleness. CCS CONCEPTS • Human-centered computing → HCI theory, concepts and models; Interaction paradigms.

EarRumble: Discreet Hands- and Eyes-Free Input by Voluntary Tensor Tympani Muscle Contraction

“…This paper introduces a subtle and discreet interaction technique that requires low efort and can be hidden from others -two areas that were recently highlighted as part of a systematic investigation into subtle interaction in the HCI literature [42]. Motivations for doing less in interaction include (a) to make interaction smaller and more comfortable [32] so that they do not cause physical discomfort [16], (b) being always available [32] and/or (c) "to execute a secondary task, for example controlling mobile applications, without interrupting the manual primary task, for instance, driving a car" [55].…”

“…hand gestures) [22] and are more socially acceptable to spectators [46]. The latter beneft also has the advantage from a user's perspective of maintaining a level of privacy over the interaction to avoid unwanted attention [42]. Microgestures and hands-free input approaches enable users to interact with their device without disrupting other tasks they may be performing, for example manual tasks such as writing a letter or driving a car [55].…”

Hybrid Body Craft: Toward Culturally and Socially Inclusive Design for On-Skin Interfaces

“…In a sense, when body crafts can wirelessly transmit information, the wearer is no longer subject to the passivity of others' gaze but can now actively communicate what they desire beyond being there, which can also be viewed as a form of subtle interaction as examined in the HCI literature. 13 For example, a woman wearing nail art that also functions as a wireless trackpad device in New York can input a message into her fingernail and transmit it to her family on the other side of the world. The following section will introduce example artifacts that expand reach to remote distance.…”

“…This affordance of technology to communicate beyond being there is also a common trend in technological developments. 13 Increase in Agency for Self-Expression Reflecting on the shift in reach and changeability, one can observe how the hybridization of technology has increased the agency to change and communicate one's identity. This increase in agency also provides opportunities for more dynamic presentations of self for our modern times.…”

AirCase: Earable Charging Case with Air Quality Monitoring and Soundscape Sonification

“…Subtle Gestures. Subtle interaction that requires low effort and can be hidden from others continues to receive attention in HCI research and was recently systematically investigated [16]. We imagine that a smart charging case carried in the pocket could be an enabler of such hidden interactions.…”