Human-Computer Interface and Usability - Assignment Example

Human Computer Interface and Usability Lecturer: Team Plan, Products and their Context a) Team Plan As a team, an understanding of the need to have some universal designs which are designs of both products and environments that allow anyone irrespective of the health or physical conditions, to effectively and comfortably make use of with no adaptations or specialization of the already existing designs. This therefore implies that life has to be made simple by coming up with products, communication devices, and environments which are considerably more usable for quite a number of people both with and without disabilities, at little or no extra costs at all. For the purpose of fully understanding possible challenges that are faced by the disabled individuals in their attempts to use computers, basic knowledge on the capabilities of such disabled persons have to be known. It is after the need identification of the disabled will it be possible to effectively apply universal designs to computer interfaces. Precisely, this paper seeks to highlight any challenges that a number of people are likely to face in their daily lives and make proper determinations on the extent to which the disabled, such as those having inadequate or no use of their arms and hands, interrelate autonomously with computer equipments. There are diverse types of disabilities, but this study will solely focus on the quadriplegics, their capabilities, an investigation on how they make use of computer equipments, and special devices available to aid their interaction needs (Hackos, & Redish, 1998). According to Microsoft Accessibility (2003), the prevailing human limitations that are related to proper computer interactions can be categorized into five major groupings; resource limitations, learning limitations, hearing limitations, visual limitations, and mobility limitations. b) Products and their contents a. Assistive Hardware Technology for quads i. Head mouse: This is a head-mounted wireless optical tracking system which helps in the translation of the users’ head movements into proportional movements of the mouse pointer. On-screen items like the icons are selected whenever the cursor is left stationary on the item for a programmable duration of time. See the illustration below: ii. Switch/Morse Code Interface: Switches are controllable by virtually any body part, and activated by a simple press, swipe, kick, eye blink, head movement, and sip and puff devices. Morse code interface is currently the most popularly used switch interface since its users have the ability to quickly adapt to using it so as to achieve high entry speeds. iii. Eye-Tracking Systems: Eye-tracking systems are virtually the alternative input devices for hands-free text entry and pointing operations. Such systems present the obvious advantages of no head-mounted technologies required. Cameras are mounted on the monitors and focused on the eyes, while integrated software gauges where users are looking into. Automatic clicks are made by either slow blinks or with hard stares, with the heads held steady. iv. Sip and puff systems: These sip and puff systems are activated by any user’s breath. Puffs are used to generate clicks or selections, thereby replacing the need for mouse buttons. b. Assistive Software Technologies for quads i. Keyboard Filters: Keyboard filters are hands-on devices that are used for word prediction, customizable dictionaries, abbreviation-expansion, and decreasing of the total number of required keystrokes. An example is the KeyRep Program (Nanopac Inc., 2003). ii. Voice or Speech Recognition Technology: This technology consists of hands-free devices that users apply in the production of texts or activation of functions simply by speaking. It is developed to relieve users of the physical exertion that is required by direct hands-on input, like is the case with Dragon NaturallySpeaking® software. iii. On-screen keyboard: On-screen keyboards are functioning images of a standard or modified keyboard which is provided on the screen, like the Onscreen v. 1.75. In such cases, the keyboard keys are activated through practically pointing any of the pointing devices. This software can be programmed further to allow key selection after a certain length of time, especially for those individuals who are able to move the mouse cursor but cannot click (Nanopac Inc., 2003). iv. Screen Readers: Screen readers are assistive software programs that are developed to verbalize contents like graphics, punctuations, texts, names, menus, and descriptions of buttons, which are displayed on the screen. An example of such a program is the JAWS®, which transforms the Graphical User Interfaces to audio interfaces through the use of internal speech synthesizer and sound cards, and lessens the efforts required to scan through the displayed output interfaces (Nanopac Inc., 2003). Task analysis, HTA Diagram, and Analysis Task analysis, in this case, is the fundamental technique in assessing and reducing any possible human difficulties in interacting with computer devices. Task analysis will be applied broadly to include the human factor techniques in the action oriented approaches, and the cognitive approaches to effectively eliminate any prevailing conditions leading usability barriers the disabled experience in interacting with computers (Mayhew, 1999). To develop a highly accepted and usable computer interface Identify those unable to use the already developed systems (the disabled) Determine their needs and incorporate them in the system development sequence to be initiated Create an interface prototype and provide it to the sampled population (the disabled) to test the level of efficiency in using the interface, in terms of; Successful task performance Time taken in completing a task Their satisfaction levels with the interface Identification of any required changes Performance analysis to see if the system meets its set usability objectives Take down users’ comments and further enhance the system prototype Finally, provide the improved interface to the users again during the testing phase/stage. If accepted, present the prototype to the system developer, or else, work further on the system basing of the intended users’ recommendations for a usable product. The Hierarchical Task Analysis (HTA) will be used in describing breakdown of work to meet the pre-set objective of this analysis. First will be the identification of the top down fashion of the overall goal of the task, then the various sub-tasks, and conditions within which they are to be carried out to ensure achievement of the study’s goal. Navigation For a successful navigation experience while using a system, interfaces play critical roles. Interfaces form the intermediaries between users and contents to be displayed, interpreters and guides to the complexities of the case sites. In this sense, the interfaces have to construct visual meanings to the intended users, i.e. the disable such the visually impaired. Thus, visual hierarchies have to depict relationships between elements on the displayed interfaces by paying accurate attention to the relative sizes of elements on any interface, looking into content placements or position, checking on proper coloring and high contrast, and being vigilant on movement which draws attention (Johnson, 1992). Usability and Usability Evaluation System or interface usability implies being in the right state and format for the recommended application by any intended users. This means that the application should be able to perform its tasks faster, easily, cheaply, correctly/ without errors, and with little inputs/strains. Usability evaluation is categorized into two major sections. The first one is the expert evaluation which further consists of heuristic and formal evaluation techniques. The formal evaluation related to the proofs of the usability of the interfaces based on the abstract techniques such as psychological and analytical criterion, which related to systems and user models. Heuristic evaluation, on the contrary, demonstrated more usefulness since it coherently relates to the evaluation of the intended system by the designers in accordance with their own intuitive understandings of quality, learnt guidelines for good designs, and/or checklists for the larger signs of system usability (Hackos, & Redish, 1998). The second major usability evaluation technique is the empirical technique. Empirical techniques involved methods that can be used to test usability of the intended system with real users, in this case the disabled, though within the laboratory settings rather than in the real-world settings. This technique, empirical, enabled our team to establish a formative evaluation process that would help in the proper redesigning of the user interfaces, or entire system applications, based on the intended users’ experience, problems, and responses (Mayhew, 1999). Findings The research findings show that the highly interactive user interfaces are often characterized by continuous responses to users’ input, instead of just waiting for the discrete tokens as in the eye-tracking system of interacting with the computers among the disables. Still on the eye-tracking system, the designing of interactive techniques has proven to be quite technical since the process of obtaining information from users’ natural eyes’ movements while viewing the screen instead of requiring the user to make specific eye movements to actuate the systems can never be consistent (Johnson, 1992). Bibliography Hackos, J. & Redish, J. (1998) User & Task Analysis for Interface Design, Wiley Johnson, P. (1992). Human-Computer Interaction: Psychology, task analysis & software engineering, McGraw-Hill Mayhew, D. (1999). The Usability Engineering Life-cycle, Morgan Kauffmann Microsoft Accessibility. Retrieved May 2003 from http://www.microsoft.com/enable Nanopac Inc. - Technology for Independence. Retrieved May 2003 from http://www.nanopac.com Read More