When: Saturday, April 26. Where: room 709. (details here)

Welcome and individual introductions (2m/participant: who, from where, interests)

Session 1: Handling the shifting boundaries of privacy

Jon Bird, David Osrin, Nayreen Daruwallah and Ed Fottrell.
Towards Using Mobile Phones to Inconspicuously Report Domestic Violence in an Indian slum
A recent study found that over 1 in 3 women have experienced domestic violence in Dharavi, a Mumbai slum, and yet most victims do not seek help to address this issue. We are supporting a new initiative by a local community organization that aims to support victims as well as more accurately record the prevalence of domestic violence in the slum. One challenge is to find a way that victims can use mobile phones to inconspicuously report incidents of domestic violence. We consider different approaches and discuss their suitability for the particular conditions in Dharavi, which include: a lack of privacy; low levels of literacy and digital skills; and the basic technology levels of most mobile phones, which are often shared by a household. Download PDF
Mohamad Salimian, Derek Reilly, Stephen Brooks and Bonnie MacKay.
Bridging physical and virtual privacy mechanisms during mixed-presence collaboration implications for inconspicuous privacy
Providing usable privacy mechanisms should be a key design concern for collaborative technologies like shared displays and telepresence systems, especially when these technologies are intended for use in public spaces. However, differences in culture, experience and background knowledge make concrete approaches problematic. We argue that in order to achieve robust privacy-sensitive designs in mixed presence collaborative systems we need to consider both inconspicuous and conspicuous privacy actions, and moreover support actions that lie on a continuum between obvious and unseen. We illustrate this through the design of physical privacy mechanisms that permit document sharing between collocated and remote collaborators. We explore each mechanism in a public “mixed reality cafeteria” setting. Download PDF
Kashyap Todi and Kris Luyten.
Suit Up!: Inconspicuous Interactions on Jacket Buttons
We present a new interaction space for wearables by integrating interactive elements, in the form of buttons, into outdoor clothing, specifically jackets and coats. Interactive buttons, or iButtons, allow users to perform specific tasks using inconspicuous gestures. They are meant for outdoor settings, where reaching for a mobile phone or other devices may not be very convenient or appropriate. Different types of buttons serve dedicated functions, and appropriate placement of these buttons makes them intuitive to use, without requiring visual contact. By adding context sensitivity, buttons can also be repurposed to fit other functions. By linking multiple buttons, it is possible to create workflows for specific tasks. We provide a description of an initial iButton design space and highlight some scenarios to illustrate the envisioned usage of interactive buttons. Download PDF
Diogo Marques, Tiago Guerreiro and Luís Carriço.
Duress Unlock: Using Covert Signals to Restrict Access to Mobile Devices
An unlocked mobile device can be a treasure trove of private information. Adversaries that are socially close to the user are in a particularly favorable position to explore it: they have access, can observe the victim’s authentication code and can even be handed the device for a legitimate task. To address this threat, we propose a new authentication concept that assumes that, by default, a user is authenticating under duress. An inconspicuous side-channel interaction with the device at authentication time dictates whether it grants regular access or enters a secure mode. This paper explores how systems based on this concept can help coping with shoulder-surfing while also allowing for impromptu device sharing. Download PDF

Coffee break

Breakout groups

Lunch break

Session 2: Sensing the user, hands-off

James Nicholson, Paul Dunphy, Vasilis Vlachokyriakos and Patrick Olivier.
Around Device Interaction for Inconspicuous Authentication?
New interactive technologies tend to bring new challenges and opportunities for designing inconspicuous interaction. In this short paper we discuss the viability of Around Device Interaction (ADI) as a method for inconspicuous user interaction. We firstly review related work in the HCI field in ADI, and then propose challenges and opportunities for ADI when applied to inconspicuous interaction. Download PDF
Alina Hang, Emanuel von Zezschwitz, Alexander De Luca and Heinrich Hussmann.
FaceProfiles: Inconspicuous, Private and Secure Mobile Device Sharing
Mobile device sharing can lead to socially awkward situations – for example when sensitive information is (un)intentionally revealed (e.g. photos). Therefore, we propose a concept called FaceProfiles that enables owners of mobile devices to share their device in a spontaneous, privacy-aware and secure manner. The concept combines two existing approaches (i.e. face recognition and rights management) to design an inconspicuous way to adapt the user interface when sharing the device, circumventing social implications like actively showing mistrust to others. Download PDF
Masato Miyauchi, Johannes Schöning and Takuya Nojima .
Listen to your Heart: Novel Ways of using Respiration and Heartbeat as Inconspicuous Input Modalities
A lot of public interactive systems still lack to exploit their full interactive potentials, as users often feel uncomfortable to interact with them as they can easily identified by bystanders while they are interacting. In some contexts users would like to perform private and inconspicuous interactions with these systems. Performing expressive gestures in the public or using a mobile phone in front of a screen is a clear indicator for others that one wants to interact with the system. In this paper we explore how the respiration rate and the heartbeat of a user can be used to allow inconspicuous interactions with interactive screens and with mobile devices in the public. We present a system, which implements the idea of the rotating compass using the heartbeat of a user to get personal information from a public screen. In addition we show how respiration can be used to interact with a mobile device in an inconspicuous way in the public. Download PDF
Niaja Farve and Pattie Maes.
Multi-modal Interactions for Inconspicuous Mobile Eye-Tracking
Multi-modal interactions have long been explored as a way to improve user experience. With the development of mobile eye-tracking technology, the advantages of using multiple input modes can be applied to mobile eye-tracking applications. The paper introduces a platform for development of mobile eye tracking called Ogle, along with a key feature it possesses the ability to develop multimodal inconspicuous applications. Similarly this paper explores the advantages of using multi-modal interactions with mobile eye-tracking technology through development of two early-stage applications. By using both gaze and audio as input the complexity of the inconspicuous system could be increased without sacrificing user experience. Download PDF

Coffee break

Breakout groups

Town Hall


Growing usage of interactive systems in public spaces has highlighted the prevalence of conflicts between desired functionality and maintenance of privacy / social comfort, inspiring some researchers and practitioners to employ inconspicuous interaction styles.

There is a clear opportunity to bring communities together to produce forward-looking insights that can shape the way users interact with tomorrow’s computers, with improved control over their circumstances.

This workshop will engage the usable security, wearable and mobile interfaces, natural user interfaces, accessibility and social interaction communities in sharing experiences and ideas and discussing goals for future research.

The ultimate goal is to identify opportunities and challenges in creating interactive systems that account for the social nomadic contexts where they are bound to be used. Particularly, it will focus on:

  • depicting current and emergent social usage patterns,
  • the threats to privacy they foster,
  • and the design space for interfaces that empower users to safeguard their privacy while not infringing on norms of social acceptance.

Organizing committee

Luís Carriço, University of Lisbon

Alexander De Luca, University of Munich (LMU)

Tiago Guerreiro, University of Lisbon

Pattie Maes, MIT Media Lab

Diogo Marques, University of Lisbon (contact organizer)

Ildar Muslukhov, University of British Columbia

Ian Oakley, UNIST

Emanuel von Zezschwitz, University of Munich (LMU)

Program committee

David Barrera, Carleton University

Andrea Bianchi, Sungkyunkwan University

Karen Church, Yahoo! Labs

Enrico Costanza, University of Southampton

Paul Dunphy, Newcastle University

Serge Egelman, UC Berkeley

Alain Forget, Carnegie Mellon University

Iulia Ion, Google

Hyoungshick Kim, Sungkyunkwan University

Marc Langheinrich, University of Lugano

Pedro Lopes, Hasso Plattner Institut

Hugo Nicolau, University of Dundee

Antti Oulasvirta, Max Planck Institut

Martin Pielot, Telefónica Research

Matthew Smith, Bonn University

Yolanda Vazquez-Alvarez, University of Glasgow

Call for participation


Topics of the workshop include but are not limited to:

  • Designing and evaluating inconspicuous interfaces
  • Making use of inconspicuous behavior in interactive systems
  • Privacy-enhancing devices and interaction styles
  • Private interactions in public displays
  • Emerging privacy threats in social contexts
  • Understanding social and cultural issues
  • Understanding contextual interaction restrictions
  • Methodological challenges
  • Limits and unexplored affordances of current interfaces


Papers should be 3-4 pages in Extended Abstracts format. The submission should be done via EasyChair.

Reviews will be double-blind, so please remove information identifying authors from your submissions. At least one author of each accepted paper must register for the workshop and at least one day of the CHI conference.

Important dates

  • Position paper submission deadline: January 24th
  • Notification: February 10th
  • Workshop: April 26th