New publication: Usability of Visibly Adaptive Smartphone keyboard layouts

We present two touchscreen smartphone keyboard interface designs which dynamically alter key sizes as the user types and highlight likely key targets, based on word completion predictions. Although we find a speed reduction and no accuracy advantage with these methods over standard QWERTY, the text entry experience on mobile devices with these designs is significantly better for users.

Gkoumas, A., Komninos A., & Garofalakis J. (2016).  Usability of Visibly Adaptive Smartphone keyboard layouts. 20th Panhellenic Conference on Informatics (PCI2016). Patras, Greece, ACM. DOI:10.1145/3003733.3003743
Download full text: 

New publication: Augmented paper maps: Design of POI markers and effects on group navigation

One popular and wide use of augmented-reality based application, is the projection of points of interests on top of the phones’ camera view. In this paper we discuss the implementation of an AR application that acts as a magic lens over printed maps, overlaying POIs and routes. This method expands the information space available to members of groups during navigation, partially mitigating the issue of several group members trying to share a small screen device. We examine two aspects critical to the use of augmented paper maps: (a) Appropriate visualization of POIs to facilitate selection and (b) augmentation of paper maps with route instructions for use in group situations. In this paper, we evaluate POI visualization in a lab setting and aug- mented paper map navigation with groups of real tourists in a preliminary field trial. Our work complements existing literature introducing self-reporting questionnaires to measure affective state and user experience during navigation.

Besharat, J., Komninos A., Papadimitriou G., Lagiou E., & Garofalakis J. (2016).  Augmented paper maps: Design of POI markers and effects on group navigation. Journal of Ambient Intelligence and Smart Environments. 8(5), 515-530., IOS Press. DOI:10.3233/AIS-160395
Download full text: 

Invited Talk: Dissecting the knowledge areas of a popular mobile application

How does a massively popular application like Instagram work? What goes on behind the scenes? What knowledge must a team of developers have to develop a service like Instagram? Together with colleague Vassilios Stefanis, I gave a presentation in the context of the 1st Summer School in ICT at the University of Patras (CEID), directed to prospective students (high-school age).

Invited talk: New ICT technologies in the quality of life for neurocognitive disease patients

I was extended a kind invitation to give a short talk on new technologies relating to the quality of life for neurocognitive disease patients (e.g. Alzheimer's), during the 6th Panhellenic Psychiatric Convention for Primary Healthcare. My talk focused on a short introduction to the concept of Ubiquitous Computing and presented a range of case studies in the use of UbiComp systems in


New publication: Field evaluation of context aware adaptive interfaces for efficient mobile contact retrieval

Our paper discusses the implementation and field evaluation of a context-aware mobile contact retrieval application. We examine the performance of our underlying prediction algorithm in real world conditions and report on the suitability of our hybrid interface design, as a replacement for traditional contact retrieval interfaces (e.g. phonebook and recent call list). We find that users are best served by an alphabetical ordering of prediction matches and show that hybrid interface designs can provide a modest benefit in users’ ability to find a contact, in cases of non-successful predictions. We also discuss users’ alternative strategies for retrieval in such cases.

Plessas, A., Stefanis V., Komninos A., & Garofalakis J. (2017).  Field evaluation of context aware adaptive interfaces for efficient mobile contact retrieval. Pervasive and Mobile Computing. 35, 51-64., Elsevier. DOI:10.1016/j.pmcj.2016.04.011
Download full text: