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Lab 4.1 Exercises

4.1.1. Apply Principles of Intuitive Design

a) Look at the icons used in the toolbar of any business application. Using what you find as examples, discuss why the everyday environment is so important.

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A1:

Answer: Regardless of the application, a great many of the icons are immediately identifiable. Pressing the button with a picture of a printer lets us print the document. Pressing the button with a picture of an opening folder lets us open a new document. Pressing the button with the scissors lets us cut out something. Other applications will have similar kinds of buttons.

We deliberately use everyday metaphors in user interface design to allow users to form predictable conceptual models. In the case of the buttons, we can make predictions about the behavior of the button by comparing the picture to its real-world equivalent.
b) Why should we look outside of the immediate task for which we are designing a user interface?

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A2:

Answer: A single task rarely exists in isolation and will be affected by and affect other tasks. We need to look at the whole work context that includes the particular task in hand. What the users' work context does is to often impose certain preconceptions (as well as misconceptions) about the way an interface should behave (or the way the program itself should behave).

One specific example of how the work context can influence the user's perception involves the text-oriented e-mail programs used for many years on UNIX systems. Users who were familiar with the capabilities of the then-available word processors often ran into trouble with the e-mail program. In a word processor, you could keep typing until the memory on your machine was exhausted without ever having to press the “enter” key.

However, this is a fatal mistake on character-based e-mail programs. Such programs are line-oriented and expect a new line at the end of the screen line. Some have a little tolerance and allow you to type more than one screen line before the trouble starts. What happens is the input buffer is only a certain size. Once that limit is reached, the program starts writing again to the beginning of the input buffer. As a result, a lot of what is typed is lost.

The documentation clearly says that the e-mail program is line-oriented. However, the users' work context said that when inputting text, you can keep on typing. The result is a lot of angry people and a lot of calls to the support hotline.

4.1.2. Understand the Basic Foundation for Good User Interface Design

a) Why does a new software package inevitably lead to increased task complexity? In that case, why do we use new software?

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A1:

Answer: All new software packages require a training period when the user's productivity will drop. To compensate, new software must bring other benefits. It must save time, increase outcome accuracy, and smooth the flow of information in some combination.

b) What is meant by a modeless user interface? Why is this important in designing a user interface?

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A2:

Answer: A modeless user interface is a user interface that appears to display only one context in order to carry out all tasks. Only dialog interrupts the context from time to time, if at all. Context switches cannot confuse the user since none are present. Knowing whether an interface is modeless helps the designer in determining if any components interact and to what extent.

Our daily life is filled with modeless interfaces, such as clocks or microwaves. In these cases, you are only performing a single task. Typically, you have a modeless interface when the functions are extremely limited. Understanding the context in which the interface will be applied can help determine whether the interface should be modeless.
c) Start up a few different graphical (as opposed to character-based) applications on your system. Compare and contrast where the menus are, what functions are in each menu, the appearance of buttons and their functions, as well as the overall behavior of the products. Pay particular attention to applications from the same vendor.

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A3:

Answer: What you find will depend on the applications you select. One of the most important things to note is how consistent everything is. Typically, you find menus labeled “File,” “Edit,” “View,” and “Help” in most office products, including Web browsers. Each of these menus generally has the same functions, differing slightly for different applications. Even the buttons on the toolbar and the functions behind them are pretty consistent across applications.

We can achieve consistency in the location of objects within the user interface and in the execution of tasks. An example is the position of the controls in the motor vehicle we are driving. Always bear in mind that the computer application itself is not central to a user's goals. Take care that the application does not obstruct the user's current task.

Within many organizations, consistency has not been an important issue, as can be seen from the myriad of form designs used. However, consistency should always be a long-term goal, requiring designers to look backward (to learn from previous experience and other applications) as well as forward (for innovative interface controls).

The clashing of command names between applications is a major problem, as users typically require more than one application to achieve complex goals. We should always remember that the habits users learn in applications they frequently use are carried to other contexts, resulting in confusion if consistency is absent.

It is important to recognize and implement the standard ways of interacting with a target system and to follow local conventions when transferring applications to different environments. Screen layouts vary widely with titles, action areas, and control information in different positions, even within a single application. It is like living in a house with all the door handles at different heights! From observing many different applications, we note that the greatest divergence between designers is in assigning different keyboard shortcuts, particularly function keys.

Making all user actions reversible is an almost impossible task, but should be the ultimate goal. Ensure that simple object-action pairs can be undone—examples are deletion and movement. Allow users to experiment with a sequence of actions, recovering by reverting to the last saved state, or one of a series of snapshots.

Remember that with few exceptions, if users cannot control your software, it is your fault, not theirs. By all means forgive users for their mistakes by providing reversibility, but hope they will forgive you for yours and buy the upgrades!

For the user, the benefit of a consistent interface is a much-sought-after perceived stability. This stability gives a feeling of predictability, robustness, and forgiveness. These characteristics engender confidence to explore and learn.

d) Look again at the applications in the previous question. Are the messages presented easy to identify and understand? Do messages appear when you think they should?

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A4:

Answer: What you find will depend on the applications you select and the actions you perform.

One very important aspect of context is the concept of a mode of operation. Modes are present when an interface view restricts the set of objects and actions presented to the user. It is vital that modes be made visible to the user in some way. Two conventional methods are:
  1. Constraints. Access to interface controls is artificially constrained, such as beeping on an access attempt or preventing the cursor from entering forbidden screen regions.

  2. Indicators. Change the interface view radically, or more subtle changes such as the shape of the cursor or “graying out” menu options, and so on.

Certain modes are near universal and should be present in the knowledge structures of most users. These are online help and the use of dialogs. Keeping modes to a minimum is one guarantee of a good user interface. There are few more frustrating aspects of the user interface than finding yourself in a new mode of which you are unaware.

At this point, there is no harm in repeating the message from the last unit on user feedback. You should acknowledge all user actions with one of the following:

  1. Immediate execution (within about one second) of the action with a visible state change

  2. Correction message

  3. Confirmation message

  4. In-progress message

It is imperative that the system responds very quickly to a user's action. This will help establish user confidence and satisfaction and assists the user to understand the dialog in progress.

In addition to a quick response, the interface designer must concentrate upon informing the user of the present context. As well, the current context should list or otherwise make visible the allowable actions from which the user can choose. More difficult is providing clues to the next interface contexts or views that can be reached from the current context and making clear the routes to those contexts.

In Figure 4.1, we attempt to summarize the steps and components of a single interaction with the user. The first point to notice is the number of different subcomponents involved in the interaction. Second, there are seven steps to be followed in order to guarantee feedback and a successful interaction from the user's point of view.

Figure 4.1. Components of an Interaction


Step 5´ attempts to show that the context remains the same provided there are no modes involved in the user interface design. This is the best that is attainable. A one-mode or modeless user interface is extremely simple and leads to little confusion for the user. Most modern word processor applications are close to attaining the modeless state. The user sees only the formatted document, as it will appear when printed. The only mode changes are dialogs that appear from time to time.

In summary, the three user interface design principles of consistency, simplicity, and context form a clear-cut foundation for the building of good user interfaces.

e) In a world where users constantly demand more features, why is simplicity important? What issues need to be addressed?

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A5:

Answer: Simplicity not only allows the programmer to keep track of the application, it makes things easier for the user. One key issue is to determine whether a particular task is really necessary or just “nice to have.” Adding just the things that are necessary helps keep the complexity down. In addition, breaking down the application into tasks and subtasks as we discussed in the previous chapter not only contributes to consistency, but also to simplicity.

Keep in mind that simplicity does not necessarily mean lack of features. The key issue is that you don't want your users having to jump through all sorts of hoops to perform simple tasks.

User interface designers should group interface controls logically, using short simple words or accepted icons that the user will easily recognize. Avoid crowded screens and provide a smooth flow of information with sensible defaults and distinct closure—making it obvious a particular task is complete.

User analysis reveals a hierarchy of command usage—make infrequent commands less intrusive for novice and casual users (majority). Remember Alan Kay's maxim quoted at the top of this chapter “simple things should be simple; complex things should be possible.”


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