No description available.

Improving communication between people and computer applications is a major concern of Human–Computer Interaction. One possible way of improving such communication is to capitalise on the way human beings use speech and gesture in a complementary manner, exploiting the redundancy of information between the input modes of a system. Redundant data input entered into a computer system through multiple modes, provides considerable scope for the resolution of error and ambiguity in the input message.

The purpose of the research described within this thesis is to provide information that can be used to improve the quality of programs and the productivity of the software industry. To fulfil this purpose, the thesis is concerned with the order in which software engineers construct solutions to software problems, the factors that influence the order in which software engineers construct solutions, and the effectiveness of constructing a solution in a particular order. Control strategies describe the order in which solutions are constructed. Four empirical studies investigating control strategies were undertaken to answer the concerns of the thesis. The aim of the first two studies was to observe the global control strategies employed by software engineers. The two studies collected verbal reports and keystroke behaviour of software engineers using Prolog and C. The results showed that software engineers used a combination of Top-Down control strategies to solve a software problem. A Children-First Top-Down control strategy was used during the initial stages of solving a complex sub-problem, while a Depth-First Top-Down control strategy was used to solve simple sub-problems. Occasionally software engineers diverged from a Top-Down control strategy. There were eight types of divergences (such as working pursuing pre-requisites) that frequently occurred within the context of six different activities (such as making alternations to a solution). The third study investigated the choice of local control strategies that supplement global control strategies. When software engineers were presented with a series of subproblems to complete, they chose to complete the four sub-problems in the order that they were presented. The software engineers did not choose to pursue the series of sub-problems in any alternative order, such as the order of Easiest-First, or AnalogiesFirst. The fourth study investigated the environmental factors that influence the software engineers' choice of global control strategies. The study also investigated whether software engineers using the Breadth-First control strategy produced better results than software engineers using alternative control strategies. Three different text editors were produced to determine under what circumstance software engineers would use the Breadth-First control strategy. The editors also recorded the behaviour of the software engineers. The software engineers would only use the Breadth-First control strategy when the text editor forced them to follow the Breadth-First control strategy. However, the performance of the software engineers was better when they were forced to use the Breadth-First control strategy than when they used their preferred control strategies.

As mobile devices become a larger part of modern society, understanding how they differ from desktop devices and how to design for them is becoming more relevant. Apple and Google have themselves published guidelines for how applications should be designed on iOS and Android, the two major operating systems on mobile devices today. But the opinions on how important guidelines are for providing users with the best experience possible differ, both in scientific writing and among industry professionals. This study focuses on platform guidelines for navigation, researching the question: What effect does platform guidelines for navigation have on the usability of a smartphone application? To investigate this a usability experiment is conducted. The independent variable manipulated is type of navigation, which adheres or does not adhere to platform guidelines, and the dependent variable measured is usability in terms of effectiveness, efficiency and user satisfaction. The results from this experiment indicate no significant differences between the navigation types in terms of effectiveness nor efficiency. Differences found in user satisfaction cannot be linked to guidelines for navigation. Although familiarity can be identified as a major factor in why users were satisfied with navigation, what users considered familiar differed. Thus the results of this study bring into question whether the platform guidelines function as conventions and cannot confirm any major effects of platform navigation guidelines on the usability of a smartphone application. / Mobila enheter blir en allt större del av det moderna samhället, i och med detta blir det även allt mer relevant att förstå hur de skiljer sig från mer traditionella enheter och hur man bör designa för dem. Apple och Google har själva publicerat riktlinjer för hur mobilapplikationer kan utformas på iOS och Android, de två största operativsystemen på mobila enheter idag. Men åsikterna om hur viktiga dessa riktlinjerna är att följa för att ge användarna den bästa möjliga upplevelsen varierar, både i vetenskapligt skrivande och bland branschfolk. Denna studie fokuserar på plattformsriktlinjer för navigation och undersöker frågan: Vilken effekt har plattformsriktlinjer för navigation på användbarheten hos en mobilapplikation? För att undersöka detta utförs ett användbarhetsexperiment. Den oberoende variabel som manipuleras är typ av navigation, som följer eller inte följer plattformsriktlinjerna, och den beroende variabeln som mäts är användbarhet när det gäller effektivitet och användarnöjdhet. Resultaten från detta experiment visar inga signifikanta skillnader mellan navigationstyperna vad gäller effektivitet. Skillnader observerade i användarnöjdhet kan inte kopplas till plattformsriktlinjerna för navigation. Även om vana kan identifieras som en viktig faktor i varför användarna var nöjda med viss navigation så varierade vad användarna var vana vid på ett sätt som inte var kopplat till platformsriktlinjerna. Resultatet av denna studie ifrågasätter huruvida plattformsriktlinjerna fungerar som konventioner och kan inte bekräfta några större effekter av plattformsnavigationsriktlinjer på användbarheten hos en mobilapplikation.

No description available.

No description available.

No description available.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science Johannesburg, May 2017. / Virtual Reality (VR) is widely used in training simulators of dangerous or expensive vehicles such as aircraft or heavy mining machinery. The vehicles often have very complicated controls that users need to master before attempting to operate a real world version of the machine. VR allows users to safely train in a simulated environment without the risk of injury or damaging expensive equipment in the field. VR however visually cuts off the user from the real environment,whichmayobtainobstructions. Usersareunabletosafelymoveorgesturewhilewearing aVRheadset. Additionallyusersareunabletousestandardinputdevicessuchasmiceandkeyboards. Bymixinginaliveviewofthetherealworld,theusercanstillseeandinteractwiththe physical environment. The contribution of this research is presenting ways of using Mixed RealitytoenhancetheuserexperienceoftraditionalVRbasedsimulators. MixedRealityimproves on traditional VR simulators by allowing the user the safety and freedom of not being cut off from the real world, allowing interaction and the tactile feedback of interacting with complex physical controls, while still allowing simultaneous use of virtual controls and by adding a real world reference point to aid in diminishing simulator sickness caused by visual motion / A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science / GR2018

The growing number of interactive visualizations on the web has made it possible for the general public to access data and insights that were once only available to domain experts. At the same time, this rise has yielded new challenges for visualization creators, who must now understand and engage a growing and diverse audience. To bridge this gap between creators and audiences, we explore and evaluate components of a design-feedback loop that would enable visualization creators to better accommodate their audiences as they explore the visualizations. In this dissertation, we approach this goal by quantifying, modeling and creating tools that manage people’s open-ended explorations of visualizations on the web. In particular, we: 1. Quantify the effects of design alternatives on people’s interaction patterns in visualizations. We define and evaluate two techniques: HindSight (encoding a user’s interaction history) and text-based search, where controlled experiments suggest that design details can significantly modulate the interaction patterns we observe from participants using a given visualization. 2. Develop new metrics that characterize facets of people’s exploration processes. Specifically, we derive expressive metrics describing interaction patterns such as exploration uniqueness, and use Bayesian inference to model distributional effects on interaction behavior. Our results show that these metrics capture novel patterns in people’s interactions with visualizations. 3. Create tools that manage and analyze an audience’s interaction data for a given visualization. We develop a prototype tool, ReVisIt, that visualizes an audience’s interactions with a given visualization. Through an interview study with visualization creators, we found that ReVisIt make creators aware of individual and overall trends in their audiences’ interaction patterns. By establishing some of the core elements of a design-feedback loop for visualization creators, the results in this research may have a tangible impact on the future of publishing interactive visualizations on the web. Equipped with techniques, metrics, and tools that realize an initial feedback loop, creators are better able to understand the behavior and user needs, and thus create visualizations that make data and insights more accessible to the diverse audiences on the web.

Designing GSS that can be used effectively by co-located groups presents a number of specific problems that do not exist with other group configurations. In particular, any GSS in a co-located setting has an overhead of use that must be recouped by its benefits, or it reduces the overall group effectiveness. In distributed groups the same basic payback is necessary, but usually the GSS is also used as a communication medium; in co-located groups, members communicate directly so this immediate payback is not available to them and the benefit must come from the decision support strand of GSS.