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It's Not Magic!

The audience stares, transfixed, at the man on the stage, hoping to catch a glimpse of his strategy. The man waves a black top hat around, showing its form and lack of contents to the interested spectators. Next, he places a red silk handkerchief in front of the hat. Shouting “Voilà!” the man drops the cloth and reaches into the hat. As the audience “Oohs!” and “Aahs!” a white rabbit hops out of the magician’s hat.

Context Is Key

Magic tricks are exciting because we are challenged to figure out what just happened and how it fooled us. We’re left to ponder and to discuss with one another the magician’s strategy and skill. This curiosity of what and how information is revealed is entertaining to us.

But guessing is not acceptable when designing mobile interfaces. On mobile devices especially, we want to eliminate the confusion. Our users are not stationary, nor are they focused entirely on the screen. They’re everywhere, and they want information quickly and to locate, identify, and manipulate it easily.

Understanding Our Users with Norman's Interaction Model

Magic confuses us because it takes advantage of our cognitive processing abilities.

Donald Norman tells us there are two fundamental principles of designing for people (Norman 1988):

A conceptual model, more commonly known today as a mental model, is a mental representation—built from our prior experiences, interactions, and knowledge—of how something works. It’s our representation of how we perceive the world.

The second principle, “make things visible,” is based on the idea that after we have col- lected, filtered, and stored the information, we must be able to retrieve it in order to solve problems and carry out tasks. Norman indicates that this principle is composed of smaller principles such as mapping, affordances, constraints, and feedback.

Figure 4-1. Pop-Up dialogs, regardless of what they look like, are used to present any controls or information the user might need, within the context of the parent page or data object. If you want to move a photo or edit an address, a Pop-Up where the image or contact is visible in the background is often the best way to do it.


Mapping describes the relationship between two objects and how well we understand their connection. On mobile devices, we’re talking about display-control compatibility. On a mobile device, controls that resemble our cultural standards are going to be well understood. For example, let’s relate volume with a control. If we want to increase the volume, we expect to slide the volume button up. If we want to read more information in a paragraph, we can scroll down, click on a link, or tap on an arrow. Problems occur when designs create an unfamiliar relationship between two objects. On the iPhone, in order to take a screenshot you must press and hold the power button and home button simultaneously. This sort of interaction is very confusing, is impossible to discover unless you read the manual (or otherwise look it up, or are told), and is hard to remember.

When designing mobile interfaces:


Affordances are used to describe that an object’s function can be understood based on its properties. For example, a handle on a door affords gripping and pulling. The properties of the door handle—its relative height to our arm’s reach, that the cylindrical shape fits

within our closed grasp—make this very clear. If an object is designed well and clearly communicates its affordance, we don’t need additional information attached to the design to indicate its use, such as signs and labels.

When designing mobile interfaces:


Feedback describes the immediate, perceived result of an interaction; it confirms that ac- tion took place and presents us with more information. In a car, you step on the accelerator and that action has an immediate result. The feedback is that you experience the car moving faster. On mobile devices, when we click or select an object we expect an immediate response. Feedback can be experienced in multiple ways: a button may change shape, size, orientation, color, or position, or very often a combination of these. A notification or message may appear, or a new page might open up. Feedback can also appeal to other senses using haptics (vibration) or sounds.

When designing mobile interfaces:


Restrictions on behavior can be both natural and cultural. They can be both positive and negative. You may remember playing with a toy consisting of different colored plastic shapes and a cylinder with those shapes as cutouts on the cylinder’s surface; the idea was to fit the yellow cube, for instance, through the square cutout in the cylinder; the red triangle through the triangle cutout; and so on. The cube would fit through the square cutout, but not the triangle cutout, and so forth. The size and shape of the objects are constraints in making the correct fit. This is an example of natural constraints (though still learned). Cultural constraints are applied to socially acceptable behaviors. For example, it’s not socially acceptable to steal from someone or throw your friend’s phone out the window to get her attention.

When designing mobile interfaces:

Norman’s Interaction Model is a framework that you should refer to when using patterns to reveal more information. For a better understanding of his model, refer to his book, The Design of Everyday Things (Basic Books).

Designing for Information

A good way to start thinking about the topic of interactive design is that it is about display- ing information. A discussion of detailed information architecture is beyond the scope of this book. However, interaction design as it pertains to presenting detailed information and results is well within the scope of our discussion.

Displaying detailed information requires an understanding of the user, his context and goals, and the information available. In many cases, information should not be hidden behind a link or other action, and should be immediately available; how useful would the clock on your mobile be if it was behind a “Current time” menu item?

If this seems extreme, consider many of the systems we encounter every day, and which are regularly griped about. For example, say you’re checking on an airplane flight. Once you sign on, most airline websites still require that you click on your itinerary and so forth to simply find out whether the flight is on time—even if you only have one flight stored under your identity.

But much other information is of a second-tier nature, and demands user input to be displayed. You must decide:

How to access the information

How to display the information

Sometimes the simple facts of the information available will demand full-page presentation of information where the user’s context and tasks may otherwise demand that it be displayed in context. Use access and display widgets carefully to provide access to the information, or reconsider whether the information architecture can be redesigned to make this simpler.

Patterns for Revealing More Information

The most common method of revealing information, that of displaying another page entirely, is not covered in these patterns, simply because there is very little to say about it. Linking widgets and the many display patterns, such as those listed in Chapter 2, cover these functions. In some cases, patterns listed in other places offer alternative methods, and these will usually be cross-referenced within the pattern. For example, Windowshade is very similar to Fisheye List and the two may both be used for the same purpose when implementing the same product on different platforms.

The patterns detailed in this chapter are concerned with specialized methods of presenting more information, which have no other uses (Lynch 1960):



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