This thesis takes a look at haptic interaction as a complementing modality with graphical user interfaces in touchscreen kiosks and vending machines. The theme was inspired by the recent development of touchscreen devices in public environments, and evaluated to be topical, due to the increasing demands for accessibility. The content consists of haptic perception related observations, explanations of haptic technologies, and discussions about design approaches for applying haptic variables.
1.1 Field of study
Touchscreen interfaces are increasingly popular and common in public environments.
They can be found, for example in all types of self-service ticket and information kiosks and vending machines at stations, airports, hospitals and shopping malls; and even at self-checkouts at stores and libraries. The emergence of touchscreen interfaces has given self-service devices a better coverage in available actions and a great potential for improving user-device interaction. With these qualities public touchscreen devices offer benefits for the majority of users in everyday basis.
From a design point of view, the genius of touchscreen user interfaces lies in combining the input and output elements [Hoggan et al. 2008]. A single solid surface of interaction enables flexible and efficient layouts for the graphically presented control items. The adaptability, intuitiveness and potential for communicative and elaborate information presentation promote usability in effective ways. With physical switches, buttons, sliders and knobs this has never been possible to the same extent. Therefore, the change of the interaction system from buttons to touchscreens is well justified.
However, even with all of its advances, touchscreen devices have not yet reached some of the natural characteristics of conventional switches: the perceptions beyond eyesight.
Public touchscreen devices rely significantly on the graphics of the interface and therefore, if the user’s vision is compromised, the use of the device becomes difficult or even impossible. This is a major issue decreasing and delimiting the possibilities of independent actions for the visually impaired. An interface relying solely on a graphical screen is an accessibility problem.
In interfaces with physical switches, visual, auditory and haptic characteristics have always been inseparable. In physical interfaces, each of these characteristics is usually
These multimodal interfaces, with their distinct features for touch and hearing, have been serving also those with limited abilities. The use of haptic and sound design in physical interfaces has in fact been so successful for non-visual accessibility, that certain touchable and hearable features have become internationally recognized and standardized in the interfaces of public devices.
Now as the inherently multimodal, physical user interfaces are being replaced by touchscreens, it is relevant to question if and how the new technology can meet the existing standards for user needs. While integration of audio has already been widely explored, proven useful and utilized in most touchscreen interfaces, the touchable (haptic) features appear to be more ambiguous to design and execute.
1.2 Research questions and aims
“Designing for meaningful tactile communication should be guided by a broad and integrated knowledge of how tactile information is encoded, transmitted, and processed at various stages of a tactile interaction.” [Pasquero, 2006]
In a pursuit of better usability, accessibility and pleasant user experiences for self-service devices in public environments, this thesis aims to clarify the factors related to haptic features in touchscreen kiosks. The initial research questions to answer are:
(1) How could touchscreen kiosks utilize haptic sensations to better include visually impaired users?
(2) What would be required for touchscreen kiosks to communicate through haptic sensations?
Guided by the quotation by Pasquero [2006], this thesis takes a look at the three different aspects of haptic interactions: the factors of processing, transmitting and encoding meanings.
1.3 Partnership
This thesis has been done in cooperation with KONE Oyj. As a major player in innovating, developing and producing solutions for enabling indoor-traffic through
elevators, escalators and automatic doors, KONE is an excellent example of a company the decision of which in interface design affect millions of end-users globally. As a service producer they are also responsible for ensuring safe and accessible interaction and passage to all of their users.
This thesis aims to offer an overview on the design factors of interactive touchscreen kiosks for the future development of KONE products.
1.4 Approach and structure
This thesis starts by describing the complexity of touchscreen use-cases in public environments in Chapter 2. Different aspects of haptic interfaces are then discussed according to a division adapted from Pasquero [2006]: in Chapter 3 I summarize aspects of haptic perception from the point of view of touch-sense processing; in Chapter 4 I continue by discussing about matters of touch transmittance, a.k.a. haptic interfaces, and finally, in Chapter 5 I collect findings and thoughts on the systems of encoding haptic messaging and makes notations on the effects of design. In Chapter 6 I evaluate the potential and usefulness of the previously presented theory for haptic design.
This thesis takes a designer approach on the topic by presenting important background information, synthesizing earlier research findings and presenting practical observations. Applications of the discussed design theory are considered hypothetically, but practical experiments are left for future work.