Zdenek Mikovec

Collaborative navigation of visually impaired

A navigation system for visually impaired users can be much more efficient if it is based on collaboration among visually impaired persons and on utilising distributed knowledge about the environment in which the navigation task takes place. To design a new system of this kind, it is necessary to make a study of communication among visually impaired users while navigating in a given environment and on their regularly walked routes. A qualitative study was conducted to gain insight into the issue of communication among visually impaired persons while they are navigating in an unknown environment, and our hypotheses were validated by a quantitative study with a sample of 54 visually impaired respondents. A qualitative study was conducted with 20 visually impaired participants aimed at investigating regularly walked routes used by visually impaired persons. The results show that most visually impaired users already collaborate on navigation, and consider an environment description from other visually impaired persons to be adequate for safe and efficient navigation. It seems that the proposed collaborative navigation system is based on the natural behaviour of visually impaired persons. In addition, it has been shown that a network of regularly walked routes can significantly expand the urban area in which visually impaired persons are able to navigate safely and efficiently.

Interactive analytical tool for usability analysis of mobile indoor navigation application

Mobile navigation applications are the ones that must be tested in real environment in order to show their usability problems. Preparation of the study in real environment is complex issue and so is the analysis of the collected data from such study. Therefore we performed usability study of mobile navigation application for visually impaired users and implemented a set of visualization plugins for IVE tool. IVE tool and visualization plug-ins were used for pre-processing and for visual analysis of collected data from the usability study of mobile indoor navigation application. We found that with IVE we were able to find approximately same amount of usability issues as without this tool, but the IVE tool increased the speed of preprocessing and annotation creation i.e. the time necessary for the analysis has been reduced.

Visualization of users' activities in a specific environment

Evaluation of user interface design is usually based on usability testing methods. In this paper we analyzed and described the user behavior in the form of the user model. The user model is built on a data set which was acquired through observation of user behavior. The criterion we use for the evaluation of the usability of interface design is the user cognitive load. We present different tools for visualization, simulation and easier analysis of the user model. Because each of the methods and tools presented use only part of the user model, in the end we present methods on how to use the complete user model to correctly describe user behavior. In order to understand such a complex model we need to have a proper visualization tool. The concept of such a visualization tool is presented at the end of this paper.

An evaluation tool for research of user behavior in a realistic mobile environment

User behavior is significantly influenced by the surrounding environment. Especially complex and dynamically changing environments (like mobile environment) are represented by a wide variety of extraneous variables, which influence the user behavior in an unpredictable and mostly uncontrolled way. For researchers, it is challenging to measure and analyze the user behavior in such environments. We introduce a complex tool—the IVE tool—which provides a unique way of context visualization and synchronization of measured data of various kinds. Thanks to this tool it is possible to efficiently evaluate data acquired during complex usability tests in a mobile environment. The functionality of this tool is demonstrated on the use case “Navigation of visually impaired users in the building with support of a navigation system called NaviTerier.” During the experiment, we focused on collection and analysis of data that may show user stress and which may influence his/her ability to navigate. We analyzed objective data like Galvanic Skin Response parameter (GSR), Heart Rate Variability parameters (HRV) and audio video recordings and also subjective data like the user’s subjective stress feeling and observation of the user’s behavior.

Automatically generated landmark-enhanced navigation instructions for blind pedestrians

Visual impairment limits a person mainly in ability to move freely and independently. Even with many navigation aids and tools currently on the market, almost one third of the visually impaired do not travel independently without a guide, and human-prepared landmark-enhanced itineraries of the route are the most useful. We designed a system which based on a specific efficiently collected geographical data generates human-like landmark-enhanced navigation instructions. The studies we conducted (quantitative n = 16, qualitative n = 6) proved usability and efficiency of the system. Further we provide set of design recommendations to increase the usability of the system along with specific examples of usage with particular landmarks.

Humsher: a predictive keyboard operated by humming

This paper presents Humsher -- a novel text entry method operated by the non-verbal vocal input, specifically the sound of humming. The method utilizes an adaptive language model for text prediction. Four different user interfaces are presented and compared. Three of them use dynamic layout in which n-grams of characters are presented to the user to choose from according to their probability in given context. The last interface utilizes static layout, in which the characters are displayed alphabetically and a modified binary search algorithm is used for an efficient selection of a character. All interfaces were compared and evaluated in a user study involving 17 able-bodied subjects. Case studies with four disabled people were also performed in order to validate the potential of the method for motor-impaired users. The average speed of the fastest interface was 14 characters per minute, while the fastest user reached 30 characters per minute. Disabled participants were able to type at 14 -- 22 characters per minute after seven sessions.

Cultural Heritage, User Interfaces and Serious Games at CTU Prague

Cultural heritage presentation is a topic we at CTU Prague deal with for more than ten years. In this paper we present our experience with user interface design where serious games paradigm has been utilized. The survey of selected projects represents various technologies and approaches for cultural heritage data handling that includes data acquisition, presentation, interaction and educational issues. The aim of our activities was to develop a systematic approach to the user interface design for the given class of applications.

BlindCamera: Central and Golden-ratio Composition for Blind Photographers

Even though the photography is a visual medium, visually impaired people use their smartphone cameras to take photos. We present a smartphone application, which helps visually impaired people to properly aim while taking portrait photographs. We have implemented an aiming assistance algorithm for two compositions (central, golden-ratio) and two feedback modalities (voice, vibration). In a study with 12 blindfolded participants we compared four combinations (composition × feedback modality) in aiming time, interaction, completion time, aesthetic quality of photos, and comfort of use. The results show that the combination of golden ratio composition with voice feedback produced the best aiming time (5.53 seconds) and completion time (8.33 seconds), the best aesthetic quality of photos, and was perceived as most comfortable. The interaction time of double click was 2.92 seconds on average and there was no significant difference between the four combinations.

KoalaPhone: touchscreen mobile phone UI for active seniors

We deal with a problem of designing a user interface for touchscreen phones with respect to special needs of seniors. We conducted qualitative study (