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===Tactical Uses=== == Tactical Uses ==

The lights in the theater dim. Voices die down. All eyes now stare at the giant illuminated screen and silence overtakes the room. Projecting now, the movie begins. Beginning from high above a city, the audiences’ view mimics the flight of a bird. Slowly, as the view trickles down below the clouds, a row of houses appear. Dropping lower, the view focuses to one house in particular. We enter the house, it’s dark, old, and abandoned. Slower now, the camera leads us down the stairs to the basement. The audience is coaxed into believing something isn’t quite right. Attention is focused on the closed closet door, now bringing and increase in fear and tension. Something terrible is about to happen; the audience waits. The camera leads the audience closer to the door. Closer. Closer. Closer. Not a sound to be heard now. Then it happens! The sound of Lady Gaga’s “Bad Romance” chimes loudly breaking everyone’s concentration. Heads turn and eyes seek to identify the location of the sound and culprit. The patron embarrassingly finds her mobile phone and switches it off. Yes, it’s annoying when someone forgets to turn off their phone. But hey, people make mistakes. Mistakes happen everyday in our lives. Some mistakes go unnoticed, while others can be quite catastrophic. Some mistakes are caused by us, others by objects in our environment. But many mistakes can be prevented!

That Was Easy

How could the mistake of the lady not turning off her phone be prevented? If only she had an “Easy” button to push that would allow her to start over and turn off her phone prior to the movie beginning. Maybe though a distributed cognitive network, her friends could have reminded her. Or maybe the situation could have been resolved if her mobile device detected that she was in a movie theater and automatically defaulted her device to vibrate.

Unfortunately, life doesn’t provide us with a personal “Easy” button to turn a complex situation filled with chaos and mistakes into one of errorless simplicity. Relying on friends, can be well....unreliable. Having our device automatically detect potential error based on our location or behavior problems seems plausible and doable.

Understanding Our Users

We must accept that we are human and we make mistakes because our body has unique limits. We are limited in our cognitive processing abilities constrained by capacity and duration. We have physical limits such as endurance and strength. We have ergonomic limits such as reach and rotation. We have perceptive limits in what certain electromagnetic and mechanical wavelengths we can detect and filter.

Mixed together with our limitations, we expel a lot of cognitive energy to process and interact with the enormous amount of stimuli in our environment. Our attention on the task at hand will affect which environmental stimuli needs to be filtered, focused on and stored. Think of our mind as a leaky bucket that is constantly being filled. As more and more stimuli are collected through sensory memory, most, during filtering, will be lost. Important stimuli will be processed and stored using our working and long-term memories. There are many theories on cognitive load, attention and problem solving. For further readings, check out Broadbent (1958), Sweets, 1984) and Sweller (1988).

Humans have also developed ways to reduce the mental load required to process information. According to Payette, this is possible because cognition is embodied, situated in an environment and distributed among agents, artifacts and external structures (Payette, 2008). We do not solely rely on our individual human limits to process information all of the time. We can embed our knowledge of the world in objects that serve as episodic reminders to help us recall. We can distribute our cognitive load to multiple agents or devices. Consider a grocery list. We can try and store all of that information in our heads and hope to recall it by the time we get to the store. More effectively, we can situate our cognition on a notebook where we can write down the entire list. We no longer need to recall each item. We just need to recall that the notebook contains the list. Further, we can distribute our cognitive load amongst others. Let's say we are in a baking class where you only make cakes. Rather than have everyone remember to buy all of the ingredients, we can assign each person a specific ingredient to purchase. Can we reduce cognitive load and error even more? Yes. Let's distribute all cognitive load onto technology. What if your refrigerator monitors your shopping habits, cooking behaviors, and can automatically sense which ingredients you need. Then it sends a grocery list order via SMS to your local supermarket. You mobile device can confirm your order was placed, the amount charged to your bank account, and notify you when your order is ready to be picked up!

Tactical Uses

Let’s put all of this to use. When designing mobile user interfaces, me must: create situations that can predict human behavior and prevent error by:

1. understanding the user’s context of use. 2. eliminating the possibility for mistake. 3. if necessary, providing a constraint that forces us to confirm a subsequent action.

1. Understanding the user’s context of use. Context of use is dependent on the user’s goal, the technology, and the environment. For example, if a user’s goal is to enlarge an image on their mobile device by touching it, the user’s risk and consequence of making a mistake is none.

Designing to Reduce Error

***NOT FINISHED***

Not all mobile devices are equipped to take on the majority of a user's mental load. So in this chapter, we will point out fundamental principles that should be used when designing for Control and Confirmations.

1. Distributing Cognitive Load

2. Feedback Describes the immediate perceived result of an interaction. It confirms that action took place and presents us with more information. In a car, you step on the accelerator. 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. Be sure to design actions that result in immediate feedback. This will limit confusion and aggravation while making the user’s experience more satisfying.

3. Constraints Restrictions on behavior can be both natural and cultural. They can be both positive and negative. Remember the toy with cut out spaces resembling geometric shapes? A child is to take a yellow plastic shape and fit it though the space in the red sphere that it matches. A cylinder fits into the circle cut out, the cube fits inside the square, but will not fit in the triangle slot, etc. The size and shape of the objects are constraints in making the correct fit. Those are examples 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 their attention. When designing mobile interfaces, use constraints to reduce or prevent user error. When you accidentally press delete instead of save, you should be provided a constraining confirmation message that requires your action. When designing to reveal information, use constraints of the size of the viewport, or have unimportant buttons become inactive.

Understanding the Context

Patterns for Control and Confirmation

Control and Confirmation (last edited 2013-04-11 00:02:34 by shoobe01)