Designing A System With Good Actability Usability Computer Science Essay

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The ability of the information system should be to help by permitting and facilitating the interpreter to accept sufficient bases to go through the planned action. The purpose of the information systems should be to help the users to be convinced to carry out what the user desires and the final information reaches the intended interpreter. (Goldkhul, Agerfalk, 2002, page 17)

According to our research the actability features of information system may be followed to answer the research question like how the booking system could be more available for the handicap people. This could be achieved by choosing what communicative action to perform, formulate the propositional content of the action and attach it to an understandable and appropriate action mode and execute the communicative action. (Goldkhul, Agerfalk, 2002)

Usability vs. Actability

From a usability perspective the purpose of using an Information System is to achieve specified goals. Actability, on other hand, focuses on the performance of actions. The usability is primarily centers on humans who actually interact with computer system, while in actability, a user is any one affected by the events performed by the system. The usability idea of 'product' is equal to the 'IS' idea of the actability. The actability puts more focus on the software components and lesser on ergonomic issues. (Agerfalk, Cronholm, 2001)

Interaction Design Principles

According to Strijbos, Kirschner and Martens (page 235, 2004) to understand the definition of the interaction design more precisely we needs to separate these two terms 'interaction' and 'design'. The interaction is a constant process of action and reaction between two parties whether humans or machines. The design is making sense (of things), then the interaction design is defined as the discipline devoted to define the actions of artifacts and the worth of communication services to its users, and the quality of the experiences they (users) have while using it. (Strijbos, Kirschner, 2004)

C:\Users\Baddar Rehmat\Desktop\thesis_uni\a-usability-of-graphic-design-4.jpgFigure 3.4: A Simple Interaction Design Model (Oleh Listia Natadjaja, 2010)

The Human Computer Interaction and User Interface Design are aimed to improve the efficiency, effectiveness and adaptation of the interaction between the user and the computer by representing, understanding and implementing models. ( Yusof, Amin, Zainudin, Baker, page 1). The purpose behind the human computer interaction is to create relation between the human and the artifact.

To improve the usability of an application, it is important to have a well designed interface and these "Eight Golden Rules of Interface Design" are claimed to be a guide to good interaction design. (Shneiderman, Plaisant, 2005). The golden rules of interface design are as follow in table:

Table 3.3: Eight Golden Rules of Interface Design(Schneiderman, Ben)

Ben Shneiderman's Eight Golden Rules of Interface Design

Strive for consistency

Enable frequent users to use shortcuts

Offer informative feedback

Design dialog to yield closure

Offer simple error handling

Permit easy reversal of actions

Support internal focus of control

Reduce short-term memory load

During the interface design phase we will try consider these golden rules, when we will to design the prototype. We might face some difficulties while the designing, when we will follow these rules, because all these rules are for the normal users. In our research the users would be the visually impaired people but we will try our best to follow these rules because in our opinion these rules are evaluated and filtered after a long time.

For the achievement of all the points that that are discussed above (theoretical points) there are some interaction design principles which could be followed, if these design principles are properly followed they will help to reach the requirements of users. For designers, these kinds of systems are challenge to design for the effective usage.

There are guidelines presented by M. C. Maguire (1999) in an article "A Review of User-Interface Design Guidelines for Public Information Kiosk Systems". These guidelines are nicely described, but the problem in these guidelines is that they may not work properly for the handicapped interacting with interactive system. More things needs to be considered while designing such interactive systems for handicapped and specifically for the visually impaired userss. To overcome this issue we will use Web Content Accessibility Guidelines (WCAG) 2.0 presented by Caldwell and Cooper (2008), these guidelines provides a broad scope of recommendations for development of more accessible web content (visual). If these guidelines followed properly they can help for the better accessibility for broad range of people with handicap disabilities, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity and combinations of these. (Caldwell, Cooper Reid, Vanderheiden, 2008) We will try to combine these two guidelines because our research demands this from us and to come up with a prototype that works for visually impaired persons.

Design Principles

The design principles that was proposed by Julie A Jacko for the ATM design for the elderly people (page 7), these design principles may be considered to work for the visually impairment people. The design is based on the simplicity and helpfulness, which are as follow

Just one operation requires at one screen

The user can perform the action in a step by step manner by only one option at one screen, and for the visually impaired people this is very important that this manner is followed to make things easy. (Julie A Jacko, 2007)

The screen switch must be noticed

The switching from one screen to the next screen must be notified to the user so that the user can know that they are moving to next step and prepares for the next step. (Julie A Jacko, 2007)

The operation flow must be comprehensible

The flow of operations must be comprehensible into input and the output, so that the user can use the system with confidence and confirmation. (Julie A Jacko, 2007)

The screen information must be easy to read(sufficient font size and contrast)

The information on the screen must be easy to read for the user with the help of sufficient font size and contrast. Other methods could be use for this delivery of information to the user by voice or announcement. (Julie A Jacko, 2007)

Screen information must be simple as possible

Screen information must be kept as simple as possible for the user by simple text. (Julie A Jacko, 2007)

The same content as announced must be displayed on the screen

The information which is displayed on screen must be announced by voice. (Julie A Jacko, 2007)

The announcement must be done at the time just before changing to the next screen, and it must not repeat

The timing of the announcement is very important it must be done just before changing to the next screen, and it must not repeat. (Julie A Jacko, 2007)

Guidelines for Public Information Kiosk

The guidelines for the design principles are as follow

Design Principles

It is so essential to follow those principles which can help us to reach the needs of customers for the ticketing machines. The preservation of user needs involves sorting out the purpose of the machine. Who will use the system? What are user's goals? And what problems could be faced in the future. It is important to have a symbol which says that the ticketing machine exists here. Maguire also says that there should a manifestation on the screen for what the machine will be used for and how it will be use, and there must be an option to stop the demonstration at any time (Maguire, 1999). It is essential for users, to place the machine at correct height for easy access of users. Especially for those sitting in wheelchair and cannot stand, be able to come and get in touch with machine. The wheelchair can be easily rolled close to the screen and keyboard, so that they can comfortably use the machine. According to the suggestion (Maguire, 1999, page 3) the maximum height of the machine should be between 70 and 120 cm from ground. To make it comfort for a person with low vision, the area around machine should be free from other equipment within a radius of 1.5 meters. It is important to clearly show the user how to enter or take payment card. Maguire suggests that a poster or a printed brochure is a great approach to show users what system contains and to show some simple steps on how the system is used. If the ticket machine will be used by foreign tourists or by international user, it is important to have multiple language option in the system. We will also consider these principles while designing prototypes for the visually impaired users (Maguire, 1999)


It is very important that when user input some data there should be security and privacy in the system. If there is lack of privacy in the system then the user will not fell friendly and confident in doing the actions. If the user is sure about the data privacy then he/she will be interact with machine smoothly and in friendly environment. The machine should be placed where the users should feel protected (Maguire, 1999).


It is important that there must be help option at each step for user, if he/she feels hesitation at any step, the users can easily get it. In this way it will be called self service system without dependency or help of other persons. If users have problem at any step then the help option and further details should transparent and simple in a way which is understandable e.g. question marks. ( Maguire, 1999)


Different types of input devices are used for ticket machine system. The most general is keyboard, touch screen, oral speech recognitions and trackball. (Maguire, 1999)


According to Maguire (1999), text, images, language, icons, colors, graphics, voice and music should according to some standards. The text should be no smaller than 16 points so that people with impaired vision have no problems to read. The text should be modest and the contrast between text and background should be high so it can easily differentiated. The text should not be colored, language should not be hard, technical terms should not be used. The colors should not be embellished, at most four to five colors should be used, and they should preferably be used in convenient ways, for example to distinguish between elements. The red and green colors should be avoided for the reason of color blindness. The graphics should be high quality but it should not contain lot of colors.

According to Maguire (1999) if the machine is in an open atmosphere, where it is crowded the people will feel it difficult to communicate with machine, it is feasible to use with a handset. It will be beneficial for people with impaired vision that can easily communicate with the receiver. Volume control option should be there. The structure, navigation and menus should be very clear so that the user knows where in the system he / she is now. The user should always have an opportunity to go back to the home page.

Menu Selections

The menu selection is very important aspect of machine, if someone does not understand it then, it is impossible to go further. The menu choices must be prominent and clear, so that the user knows roughly what the information or features present in it. If the system is inactive for a couple minutes then it should be automatically positioned on the home page again, but it should happen in a proper and specific time so that the user can not be frustrated. (Maguire, 1999)


The interface should be able to be smoothly modified to users' needs and skills. They should also be provided by the things that they can customize the interface on their own. (Maguire, 1999)

Shneiderman's Eight Golden Rules of Interface Design

"Eight Golden Rules of Interface Design" are claimed to lead to good interaction design. (Shneiderman, 2008)

Strive for consistency

A stable chain of events should be necessary in parallel situations; the similar terms should be used in menus, prompts, and facilitate screens; and fixed commands should be engaged throughout. (Shneiderman, 2008)

Enable frequent users to use shortcuts

There should be some shortcuts for daily users so they can easily perform their specific task instead of using long regular procedures. Microsoft Word is one of example for this in which you can use ctrl +c and ctrl +z to copy or undo any event, so there should be facility for user to save time. (Shneiderman, 2008)

Offer informative feedback

For every action to perform there should be some backup or indication from the machine, which indicates and give you options that you can go further to the next step. While for the final and sensitive actions related to bank transitions, there must be text message on your screen or mail options that this action is performed successfully. There should be some record options for users to keep it save with them. (Shneiderman, 2008)

Design dialog to yield closure

The easy information should be at start, and informative options should be at the end. The system should be design in such a way that the user is mentally prepared for what information it will ask me in the next step, so the user is sure and satisfies of his/her achievements. (Shneiderman, 2008)

Offer simple error handling

While designing a system, there should not be options of small errors, which are difficult for user to detect and handle. If there are some minor and serious errors then the system should be able to detect the bugs and provide simple and intelligent mechanisms for removing of bugs. (Shneiderman, 2008)

Permit easy reversal of actions

There must be easy and reliable option in machine design to remove and undo action without any hesitation. There must be saving option when you want to go back and also option to detect and sort out the steps that you performed wrongly. (Shneiderman, 2008)

Support internal focus of control

Experienced users always wish that they should be in charge of the system while using each action of it, instead of the system is in charge of user and perform every action. The designing of the system should be in a sense to make the users starter of action instead of the responders of action. (Shneiderman, 2008)

Reduce short-term memory load

The short term memory of the users should also be reduced. The display of the system should be kept simpler, window-motion frequency should be reduced, and enough time should be given to codes, mnemonics and sequences of actions. (Shneiderman, 2008)

Summary of Theoretical Findings

The essential figures which can take us to our goal to generate prototype of ticketing system for visually impaired people and to answer the research questions, consists of key concepts like design principle, booking systems or machine, system availability, users with handicaps, system intelligence, actability, user needs, usability and user interaction. The subject areas relevant to our research question contains areas like interaction design, system development, usability design, artificial intelligence, user-centred design, human computer interaction and interactive kiosk system. These key concepts and subject areas can help us to get our goal easily and answer our questions on theoretical base. We should aware of that for whom we are designing, or who will be beneficial from it. We should keep the users at front. The system must be user-centred, usable and the principles of human computer interaction must be considered. If we want to be victorious in our goal then we must be on proper track to make an excellent and friendly human computer interaction among the specific system and the users. The machine´s user interface should be more users friendly and intelligent, that have voice reorganization facility in it, and there should be specific keyboard in the system for visually impaired users. The users with visual impairment may face many difficulties while using the public information kiosks like ticketing machine. These difficulties can be input, output, understanding the operation flow and switching from one step to next step etc, these difficulties can be minimized or removed by following the proper designing principles for the visually impairment people.

How much intelligence may be used so that the system may recognize the user and perform task according to the user needs?

This sub question can be answer by the key concepts like system intelligence, actability, user´s needs and usability. We have evaluated these concepts in detail and understand that if the visually impaired users need to interact with the system, the system needs to be intelligent, otherwise it might not be possible because the only available communicative sense the user may have will be the voice. With the help of usability and actability the system can be made more usable and available to the users. For example an interactive artificial intelligent agent can be used in the system to interact with the visually impaired users through voice and which can understand the users' speech/voice and could reply accordingly and intelligently to complete the goal.

What kind of difficulties the handicap with visual impairment could face while using these machine and to an extent the solution of that difficulties?

From research it is clear that there are many problems which blind or visually impaired people faces during performing their daily life events, because they can't see perfectly as a normal human. There are many problems like using laptops, driving cars, handling kiosk machines, and many more. For all of this they need special care from normal people. It is only possible if scientists and researchers are going to invent any new machine, they should take care of people in sense of how people with disabilities will handle the machine. There should be some special type of keyboard and voice recognition facility in it which can work for all type of users. The whole process for booking ticket should be efficient and flexible, so it will be easy for them to purchase ticket or complete a task. There should be option of making size of font large, zoom, help about every page and control the volume of the sound, so the user can easily adjust according to their requirements.

How can the machine and user interact with each other?

The question of the how the machine and the user interact with each other is possible to answer by understanding the subject area of the human computer interaction and from the concept of user interaction with the machine or the system. For the users who are not able to visualize the surroundings the study of the understanding of the principles of the interaction between the user and the machine becomes more important. The interaction should be made flexible and smooth, by the help of exploration of the user requirement and their constraints in using different kind of systems. The human computer interaction may consist of three main steps i.e. input, processing and output. The input from the user can be given to the machine by voice and the keyboard, the processing can be done step by step through voice (or without voice) between the user and the machine, and the output will be the ticket, schedule or whatever the user required.

Arguments for an Empirical Study

Since very little has been published on information kiosks in any forum, it has been necessary to develop a common framework to analyze (Slack, Rowley, 2002, page 70). Till now the situation almost the same, as it is said earlier that this kind of work is not done specifically for the visually impaired people before, hence it is not necessary that the theoretical study answer our research questions completely. There are many questions that have not yet been answered in the theory for example does a visually impaired person used ticketing machine or such kind of system? If Yes how? How they perceive the ticketing systems? There are many questions that need to be answered which cannot be answered by the theoretical study; we can only get the answers by interviews and the observations from the actual users who would use the system.