Principles of User Interface Design (Part II)


Yesterday I posted the first part of the principles of the design of user interfaces of Joshua Porter. Here the second part.

  1. Strong visual hierarchies work best

    A strong visual hierarchy is achieved when there is a clear viewing order to the visual elements on a screen. That is, when users view the same items in the same order every time. Weak visual hierarchies give little clue about where to rest one’s gaze and end up feeling cluttered and confusing. In environments of great change it is hard to maintain a strong visual hierarchy because visual weight is relative: when everything is bold, nothing is bold. Should a single visually heavy element be added to a screen, the designer may need to reset the visual weight of all elements to once again achieve a strong hierarchy. Most people don’t notice visual hierarchy but it is one of the easiest ways to strengthen (or weaken) a design.

  2. Smart organization reduces cognitive load

    As John Maeda says in his book Simplicity, smart organization of screen elements can make the many appear as the few. This helps people understand your interface easier and more quickly, as you’ve illustrated the inherent relationships of content in your design. Group together like elements, show natural relationships by placement and orientation. By smartly organizing your content you make it less of a cognitive load on the user…who doesn’t have to think about how elements are related because you’ve done it for them. Don’t force the user to figure things out…show them by designing those relationships into your screens.

  3. Highlight, don’t determine, with color

    The color of physical things changes as light changes. In the full light of day we see a very different tree than one outlined against a sunset. As in the physical world, where color is a many-shaded thing, color should not determine much in an interface. It can help, be used for highlighting, be used to guide attention, but should not be the only differentiator of things. For long-reading or extended screen hours, use light or muted background colors, saving brighter hues for your accent colors. Of course there is a time for vibrant background colors as well, just be sure that it is appropriate for your audience.

  4. Progressive disclosure

    Show only what is necessary on each screen. If people are making a choice, show enough information to allow them the choice, then dive into details on a subsequent screen. Avoid the tendency to over-explain or show everything all at once. When possible, defer decisions to subsequent screens by progressively disclosing information as necessary. This will keep your interactions more clear.

  5. Help people inline

    In ideal interfaces, help is not necessary because the interface is learnable and usable. The step below this, reality, is one in which help is inline and contextual, available only when and where it is needed, hidden from view at all other times. Asking people to go to help and find an answer to their question puts the onus on them to know what they need. Instead build in help where it is needed…just make sure that it is out of the way of people who already know how to use your interface.

  6. A crucial moment: the zero state

    The first time experience with an interface is crucial, yet often overlooked by designers. In order to best help our users get up to speed with our designs, it is best to design for the zero state, the state in which nothing has yet occurred. This state shouldn’t be a blank canvas…it should provide direction and guidance for getting up to speed. Much of the friction of interaction is in that initial context…once people understand the rules they have a much higher likelihood of success.

  7. Great design is invisible

    A curious property of great design is that it usually goes unnoticed by the people who use it. One reason for this is that if the design is successful the user can focus on their own goals and not the interface…when they complete their goal they are satisfied and do not need to reflect on the situation. As a designer this can be tough…as we receive less adulation when our designs are good. But great designers are content with a well-used design…and know that happy users are often silent.

  8. Build on other design disciplines

    Visual and graphic design, typography, copywriting, information architecture and visualization…all of these disciplines are part of interface design. They can be touched upon or specialized in. Do not get into turf wars or look down on other disciplines: grab from them the aspects that help you do your work and push on. Pull in insights from seemingly unrelated disciplines as well…what can we learn from publishing, writing code, bookbinding, skateboarding, firefighting, karate?

  9. Interfaces exist to be used

    As in most design disciplines, interface design is successful when people are using what you’ve designed. Like a beautiful chair that is uncomfortable to sit in, design has failed when people choose not to use it. Therefore, interface design can be as much about creating an environment for use as it is creating an artifact worth using. It is not enough for an interface to satisfy the ego of its designer: it must be used!