OM410 – User Interface Design [Discussion Questions]
01 What is usability?
Usability is the measure of a product’s potential to accomplish the goals of the user.
Usability means making products and systems easier to use, and matching them more closely to user needs and requirements i.e. Usability is the ease of use and learnability of a human-made object. The object of use can be a software application, website, book, tool, machine, process, or anything a human interacts with.
Usability testingis a method by which users of a product are asked to perform certain tasks in an effort to measure the product’s ease-of-use, task time, and the user’s perception of the experience.
02 What are the other software quality factors other than usability?
Software quality factors are attributes of the software that, if they are wanted and not present, pose a risk to the success of the software, they include:
Ø Correctness: Extent to which a program satisfies its requirements
Ø Reliability: Extent to which a program can be expected to perform its intended function with
Ø Performance and Efficiency: The amount of computing resources and code required by a program to perform a function.
Ø Security and Integrity: Extent to which access to software or data by unauthorized persons can be
Ø Usability: Effort required learning, operating, preparing input, and interpreting output of a
Ø Maintainability: Effort required locating and fixing an error in an operational program.
Ø Testability and Managability: Effort required testing a program to ensure that it performs its intended function.
Ø Flexibility: Effort required modifying an operational program or system.
Ø Platform Compatibility and Portability: Effort required in transferring software from one configuration to another.
Ø Reusability: Extent to which a program can be used in other applications – related to the
packaging and scope of the functions that programs perform.
Ø Interoperability: Effort required to couple one system with another.
Ø Scalability:A scalable system responds to user actions in an acceptable amount of time, even if load increases.
03 State the six usability factors
Usability consultant Jacob Nielsen and computer science professor ben Shneiderman have written (separately) about a framework of system acceptability where usability is a part of “usefulness”
1. Learnability– How easy is it for users to accomplish the basic tasks the first time they encounter the design?
2. Efficiency– Once more has learned the design, how quickly can they perform task.
3. Memorability– When users return to the design after a period of not using it, how easily can they’re establish proficiency?
4. Errors– How many errors do users make, how severe are these errors and how easily can they arerecover from the errors.
5. Satisfaction– How pleasant is it to use the design?
6. Accessibility– Does the product meet the special needs of disabled users? (Is it accessible?)
04 What are the three major kinds of defects in a system?
05 Describe the following ways of identifying usability problems
(a) Heuristic evaluation
A usability evaluation– method in which one or more reviewers, preferably experts, compare a software, documentation, or hardware product to a list of design principles (commonly referred to as heuristics) and identify where the product does not follow those principles.
A heuristic evaluation is a usability inspection method for computer software that helps to identify usability problems in the user interface (UI) design. It specifically involves evaluators examining the interface and judging its compliance with recognized usability principles (the “heuristics”).
The main goal of heuristic evaluations is to identify any problems associated with the designof user interfaces. Usability consultant Jakob Nielsen developed this method on the basis of several years of experience in teaching and consulting about usability engineering.
Jakob Nielsen’s heuristics are probably the most-used usability heuristics for user interface design. Nielsen developed the heuristics based on work together withRolf Molich in 1990 and they include:
Ø Visibility of system status – The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.
Ø Match between system and the real world – The system should speak the user’s language, with words, phrases and concepts familiar to the user, rather than system-oriented terms.
Ø User control and freedom – Users often choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.
Ø Consistency and standards – Follow platform conventions.
Ø Error prevention – Even better than good error messages is a careful design which prevents a problem from occurring in the first place.
Ø Recognition rather than recall – Minimize the user’s memory load by making objects, actions, and options visible.
Ø Flexibility and efficiency of use –
Ø Aesthetic and minimalist design – Dialogues should not contain information which is irrelevant or rarely needed.
Ø Help users recognize, diagnose, and recover from errors
Ø Help and documentation – Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation.
Ø Heuristic evaluation falls within the category of usability engineering methods known as Discount Usability Engineering.
Ø The primary benefits of these methods are that they are less expensive than other types of usability engineering methods.
Ø They require fewer resources.
Ø Reduces the cost of the project.
Ø The users benefit from a more usable product.
Ø Inexpensive relative to other evaluation methods.
Ø Intuitive, and easy to motivate potential evaluators to use the method.
Ø Advanced planning not required.
Ø Evaluators do not have to have formal usability training.
Ø Can be used early in the development process.
Ø Faster turnaround time than laboratory testing (Kantner& Rosenbaum, 1997).
Ø Getting experts with vast knowledge of usability is difficult.
Ø Individual evaluators identify a relatively small number of usability issues.
Ø May not identify as many usability issues as other usability engineering methods, e.g.usability testing.
Ø Heuristic evaluation may identify more minor issues and fewer major issues than would be identified in a think-aloud usability test.
Ø Heuristic reviews may not scale well for complex interfaces.
Ø Does not always readily suggest solutions for usability issues that are identified.
Ø Biased by the preconceptions of the evaluators.
Ø As a rule, the method will not create “eureka moments” in the design process.
Ø In heuristic evaluations, the evaluators only emulate the users – they are not the users themselves.
Ø Heuristic evaluations may be prone to reporting false alarms – problems that are reported that are not actual usability problems in application.
(b) User review
06 Discus highlighting the pros and cons of using the following ways to measure usability
(a) Task time
(b) Problem counts
(c) Keystroke counts
(d) Opinion poll
(e) Guideline adherence
07 What is a gestalt law? State and explain all the gestalt laws
Gestalt principles, or gestalt laws, are rules of the organization of perceptual scenes.
These principles mainly apply to vision, but there are also analogous aspects in auditory and somatosensory perception.
1. Law of Closure—The law of closure states that individuals perceive objects such as shapes, letters, pictures, etc., as being whole when they are not complete. Specifically, when parts of a whole picture are missing, our perception fills in the visual gap. Research shows that the reason the mind completes a regular figure that is not perceived through sensation is to increase the regularity of surrounding stimuli.
For example, the figure that depicts the law of closure portrays what we perceive as a circle on the left side of the image and a rectangle on the right side of the image. However, gaps are present in the shapes.
2. Law of Proximity—The law of proximity states that when an individual perceives an assortment of objects they perceive objects that are close to each other as forming a group. For example, in the figure that illustrates the Law of proximity, there are 72 circles, but we perceive the collection of circles in groups.
3. Law of Similarity—The law of similarity states that elements within an assortment of objects are perceptually grouped together if they are similar to each other. This similarity can occur in the form of shape, colour, shading or other qualities.
For example, the figure illustrating the law of similarity portrays 36 circles all equal distance apart from one another forming a square. In this depiction, 18 of the circles are shaded dark and 18 of the circles are shaded light. We perceive the dark circles as grouped together, and the light circles as grouped together forming six horizontal lines within the square of circles.
4. Law of Symmetry—The law of symmetry states that the mind perceives objects as being symmetrical and forming around a center point.
For example, the figure depicting the law of symmetry shows a configuration of square and curled brackets. When the image is perceived, we tend to observe three pairs of symmetrical brackets rather than six individual brackets.
5. Law of Common Fate—The law of common fate states that objects are perceived as lines that move along the smoothest path. Experiments using the visual sensory modality found that movement of elements of an object produce paths that individuals perceive that the objects are on. We perceive elements of objects to have trends of motion, which indicate the path that the object is on. The law of continuity implies the grouping together of objects that have the same trend of motion and are therefore on the same path. For example, if there are an array of dots and half the dots are moving upward while the other half are moving downward, we would perceive the upward moving dots and the downward moving dots as two distinct units
6. Law of Continuity—The law of continuity states that elements of objects tend to be grouped together, and therefore integrated into perceptual wholes if they are aligned within an object. In cases where there is an intersection between objects, individuals tend to perceive the two objects as two single uninterrupted entities. Stimuli remain distinct even with overlap. We are less likely to group elements with sharp abrupt directional changes as being one object.
7. Law of Good Gestalt—The law of good gestalt explains that elements of objects tend to be perceptually grouped together if they form a pattern that is regular, simple, and orderly. This law implies that as individuals perceive the world, they eliminate complexity and unfamiliarity so they can observe a reality in its most simplistic form. Eliminating extraneous stimuli helps the mind create meaning. This meaning created by perception implies a global regularity, which is often mentally prioritized over spatial relations. The law of good gestalt focuses on the idea of conciseness, which is what all of gestalt theory is based on. This law has also been called the law of Prägnanz. Prägnanz is a German word that directly translates to mean “pithiness” and implies the ideas of salience, conciseness and orderliness.
8. Law of Past Experience—The law of past experience implies that under some circumstances visual stimuli are categorized according to past experience. If two objects tend to be observed within close proximity, or small temporal intervals, the objects are more likely to be perceived together. For example, the English language contains 26 letters that are grouped to form words using a set of rules. If an individual reads an English word they have never seen, they use the law of past experience to interpret the letters “L” and “I” as two letters beside each other, rather than using the law of closure to combine the letters and interpret the object as an uppercase U.
08 Show how gestalt laws apply to
(a) screen layout
09 what is a contrast? Explain why contrast should be used moderately.
10 Discuss the following ways of presenting data
(d) Hierarchies (trees, nested menus)
11 Explain several ways of expressing numbers using an analog tool i.e. explain analog ways ofexpressing numbers.
12 What is an interface?
ü An interface is a device or program enabling a user to communicate with a computer i.e. “a graphical user interface”.
ü Some computer interfaces such as a touchscreen can send and receive data, while others such as a mouse or microphone, can only send data.
13 What is the use of a user interface?
ü The goal of this interaction is effective operation and control of the machine on the user’s end, and feedback from the machine, which aids the operator in making operational decisions.
ü Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machineryoperator controls, and process controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology.
ü A user interface is the system by which people (users) interact with a machine. The user interface includes hardware (physical) and software (logical) components. User interfaces exist for various systems, and provide a means of:
· Input, allowing the users to manipulate a system
· Output, allowing the system to indicate the effects of the users’ manipulation
ü Generally, the goal of human-machine interaction engineering is to produce a user interface which makes it easy (self exploratory), efficient, and enjoyable (user friendly) to operate a machine in the way which produces the desired result. This generally means that the operator needs to provide minimal input to achieve the desired output, and also that the machine minimizes undesired outputs to the human.
ü With the increased use of personal computers and the relative decline in societal awareness of heavy machinery, the term user interface is generally assumed to mean the graphical user interface, while industrial control panel and machinery control design discussions more commonly refer to human-machine interfaces.
ü Other terms for user interface include human–computer interface (HCI) and man–machine interface (MMI).
14. What are the features of a good interface?
ü While designing, we need to keep in mind the user experience and interaction (user-friendly interface).
ü The main target behind designing an interface design is to make the user’s interaction as simple and efficient as possible.
ü Clarity means the information content is conveyed accurately.
ü It helps prevent user errors, makes important information clear and gives a perfect user experience.
ü Enables users to interact with your system by communicating meaning and function.
ü If users can’t figure out how your application works or where to go on your website they’ll get confused and frustrated.
What does that do? Hover over buttons inn WordPress and a tooltip will pop up explaining their functions.
ü Clarity in a user interface is great; however, you should be careful not to fall into the trap of over-clarifying.
ü It is easy to add definitions and explanations, but every time you do that you add mass; your interface grows.
ü Add too many explanations and your users will have to spend too much time reading through them.
ü Keep things clear but also keep things concise.
ü When you can explain a feature in one sentence instead of three, do it. When you can label an item with one word instead of two, do it.
ü Save the valuable time of your users by keeping things concise.
The volume controls in OS X use little icons to show each side of the scale from low to high.
ü It enables users to develop usage patterns which will make them learn what the different buttons, tabs, icons and other interface elements look like thereby easily recognizing them.
ü They’ll also learn how certain things work, and will be able to work out how to operate new features quicker, extrapolating from those previous experiences.
ü A unique design with conformity on user’s end speaks for a good user interface design.
The Microsoft Office user interface is consistent for a reason.
While designing a user interface what must be kept in mind is legibility which means you need not use complicated words which might be difficult to read and understand instead use easy language and make sure your design includes information that is easy to read.
ü By responsive user interface design we mean that there should be no time lag in loading; it should be quite fast! Witnessing good loading speed is sure to enhance the user experience.
ü Besides, it should provide informative stuff to the user about the task in hand.
ü Also, the interface should provide some form of feedback to the user; the interface should let users know as to what happening e.g. the button should displays a ‘pressed’ state to give the feedback that your press action has succeeded or Enable/Disable the state.
ü It’s a wise idea to play a spinning wheel or show a progress bar to know that the software is stuck or the content is loading to keep the user in the loop.
ü Example: Perhaps the button text could change to “Loading…”and it’sstate disabled. Instead of gradually loading the page, Gmail shows a progress bar when you first go to your inbox. This allows for the whole page to be shown instantly once everything is ready.
ü The best user interface design is the one that forgives users on making the mistake thereby making the user undo the wrong actions without any fuss.
ü A good interface should enable user to restore the deleted items which at one point or the other can be done unintentionally.
ü Nowhere while using the interface design user should feel lost.
ü Make sure your design is such that it guides the user when a mistake is made by the user unintentionally.
ü In short user actions should be reversible.
Trashed the wrong email by mistake? Gmail lets you quickly undo your last action.
ü Many designers strive to make their interfaces ‘intuitive’; something that can be naturally and instinctively understood and comprehended by making it familiar.
ü Familiar is just that: something which appears like something else you’ve encountered before.
ü Identify things that are familiar to your users and integrate them into your user interface.
GoPlan’s tabbed interface. Tabs are familiar because they mimic tabs on folders. You figure out that clicking on a tab will navigate you to that section and that the rest of the tabs will remain there for further navigation.