Chapter 3: Interaction Design Basics

The Elements of Interaction Design:



Motion - What moves and gains the users attention and interaction through motion.

Space - The space between objects of interactivity.  The relationship between the objects that influence the interactivity and success of the design.

Time - Consists of three basic foundations:  Pace, Reaction, Context.  Pace is how fast or slow, reaction is the reaction time to a given interactivity, and context is in what space or place the interactivity takes place.

Appearance - The way a design looks.  The way interactive design looks can be either harmonious or dissonant.

 

Texture - The way interactive designed objects feels in your hand

The Laws of Interaction Design:

Moore's Law - Every 2 years the number of transistors on integrated circuits will double. This law can't really interaction designers, but they should be aware of it. And so far, this law has proved true.

Fitts' Law - The time it takes to move from a starting position to the final target is determined by two factors: the distance and size of the target. The larger and closer a target the faster it can be pointed to. Buttons should be large, menus should be along the corners or edge of a page, and pop-up menus should open close to where the user is working. Right click menus are more accessible than drop-down menus at the top of a page.

Hick's Law - The time it takes for users to make decisions is determined by the number of possible choices they have. It's also affected by familiarity and format of choices.

Magic Number Seven - The human mind is best able to remember groups of 7 items in short term. Some designers take it to the extreme never having any more than 7 items on a screen, but this isn't what the law is about. A device or site should never test anyone to remember more than seven items at a time in a short amount of time. When looking for an example of this I noticed websites of several artists where only seven items were on the screen.

Tesler's Law - There's a point beyond which you can't simplify any further, you can only move the inherent complexity from one place to another. Designers should be aware of this and look for sensible ways to move the complexities. Websites like Google really can't get any simpler without doing their job. The search engine even tries to guess what you're typing so you might find what you're looking for faster.

Poka-Yoke Principle - Avoiding inadvertent errors, usually by forcing users to adjust their behavior to execute operations correctly. An example is USB cords are made to fit only where they are supposed to be plugged in instead of fitting where the headphones should go. Another example used by web designers is pop-ups informing the necessity of Flash of Javascript to view a page.

Direct and Indirect Manipulation - Direct: Selecting an object with the mouse or hand and then manipulating it: move it, turn it, scale it, change color. Indirect: Using the menu or keys on the keyboard to indirectly manipulate an object.

Feedback and Feedforward - Every action conducted by a user should result in some type of feedback (Ex. Moving the mouse should move the cursor.) It's up to the designer to determine how a product will respond and how fast. Feedforward lets user know what will happen next.


Characteristics of Good Interaction Design:

Trustworthy – user’s satisfaction in knowing that their product will function properly without malfunctioning right away.

 

Appropriate – focuses on gearing the product’s design with an understanding of culture, customs, sex, and age.

Smart – products/services are designed to be smarter than the user so that it may answer/solve problems efficiently/effectively.

Responsive – responds accordingly to user’s request.

Clever - a useful feature that the user may not have realized they needed but enjoys its purpose.

Ludic – service/product playful and gives the user the environment and means to play with a product.

Pleasurable – a well-designed product that makes a product enjoyable, reliable, and pleasurable.