User Centric Design (UCD) can enhance the usability and usefulness of everything from "everyday things" (D. Norman) to software to information systems to processes. . . anything with which people interact. As such, User-Centered Web Design concerns itself with both usefulness and usability.
Usefulness
Usefulness relates to relevance; do the functions, information, etc., match what the user actually requires?
There are certain global usability principles, or guidelines. As they apply to web development,
Usability
Usability relates to ease-of-use—a simple concept, but not always easy or intuitive to implement.
Many of these guidelines can be summarized as follows:
Visibility
Visibility helps users form correct mental models of the 'thing'—models that help users predict the effect(s) of their actions. Important essentials (such as those that aid navigation) should be highly visible. Users should be able to tell at a glance what they can and cannot do.
Feedback
When a user performs an action, she should receive immediate feedback. For example, when the user clicks a button, something on the screen should change so the user knows the system has registered her action.
Accessibility
Users require to find information quickly and easily:
- Offer users a few ways to find information (such navigational essentials, search functions, website design map, etc). However, don’t offer too many options at once as this confuses many users.
- ‘Chunk’ information into small, digestible pieces and organize them into some type of schema or hierarchy that is relevant to the user.
- Enable skimming; provide guidance that allow users to find their ‘nugget’ of information’ by scanning rather than reading.
Navigation & Information Architecture
Web users often report feeling lost. There are multiple ways to help users orient themselves:
- Links should be imformative enough so that users can easily predict what they will find when they click a particular link.
- The user should be able to visualize the website design’s structure.
- There should be no ‘dead-end’ pages from which users can’t, or don’t know how, to exit.
- Everypage should have clearly visible essentials telling users what page they are on, where they are in relation to other pages, and how to get to other pages. (Users enter website designs from many places; they don’t always enter a website design via the home page.)
- Use frames sparingly, if at all. With frames, the back button, printing, and bookmarking functions do not work like they do on non-frames pages, confusing many users. Close to 60% of web users employ the back button as their primary means of navigation, so it is no small usability problem when it doesn't work the way they expect.
Memory Load
The website design should decrease user memory load. Screen essentials should be relevant and consistent across the website design so users can recognize, instead of remember, what essentials mean from one page to another. New items and functions should relate to ones the user already knows.
Errors
An error is an incorrect action by the user such as clicking the wrong link. It is important to minimize user errors and provide users with mechanisms that allow them to recover quickly from errors.
Satisfaction
The website design should be pleasant to use and look at. Users’ perception of ‘pleasantness’ influences their:
- Perception of ease-of-use
- Motivation for learning how to use the website design
- Confidence in the reliability of the website design’s information
Legibility
Text should be easy to read:
- Sans serif fonts are usually easier to read online than serif fonts—especially in body text.
- Ornamental fonts are hard to read.
- Italics are hard to read online.
- Body text that is too large or too small is hard to read. (9-11 pt sans serif and 11-12 pt serif seems to work well. However, it is difficult to make a hard and fast rule since individual typefaces can appear larger or smaller than their point size would indicate.)
- Text in all capital letters is hard to read.
- Blocks of text longer than 50+ characters significantly slow reading.
- High contrast between text and background increases legibility. Dark text against a light background is most legible.
To foster clarity, use the following:
- Short sentences
- ‘Everyday’ words (instead of jargon or technical terms)
- Active voice, active verbs
- Verbs (instead of noun strings or nominalizations)
- Simple sentence structure
By its very nature, the Web crosses cultural and national boundaries. For this reason, it is best to be careful with ambiguity in the form of:
- Humor (Humor does not translate well across cultures: at best, it is not understood, at worst, it can offend.)
- Metaphors
- Icons
- Idioms
- Puns
Visual design should be the user's ally. To this end,
- use grids for preliminary page layout
- create pages that are interesting, yet simple and uncluttered.
- use graphics to:
- illustrate/inform (not decorate).
- increase the user’s satisfaction/motivation.
- aid navigation.
- use graphics that are small (in file size) so they download quickly.
- make the most important essentials the most visually prominent.
- treat text as a graphic element.
- use color conservatively. Color can engage users, both emotionally and cognitively, but misapplication of color creates negative outcomes. (Try your design in monochrome first, then, one at a time, add a few colors.)
- group like essentials together.
- use ‘white space’ to visually organize the page, to make important essentials stand out, and to give users’ eyes some resting space.
1. Involve users from the beginning
Guidelines can provide general information about users and user/web interaction. However, that is not enough to make a particular website design usable; it is critical to discover how your particular users interact with this particular website design.
Involve users from the beginning by:
- Discovering their mental models and expectations
- Including them as an integral part of the design/development process and team
- Observing them at their workplace; validating your assumptions about them; analyzing their tasks, workflow, and goals
- Eliciting feedback via walk-throughs, card sorting, paper prototypes, think-aloud sessions, and other methods
Ask questions such as the following and use the answers to guide development and design decisions:
- How much experience do the users have with:
- Computers?
- The Web?
- Domain (subject matter)?
- What are the users’ working/web-surfing environments?
- What hardware, software, and browsers do the users have?
- What are the users’ preferred learning styles?
- What language(s) do the users speak? How fluent are they?
- What cultural issues might there be?
- How much training (if any) will the users receive?
- What relevant knowledge/skills do the users already posses?
- What do the users require and expect from this web website design?
Observe and interact with users (preferably at their workspace) as you attempt to answer questions such as:
- What are the tasks users require to perform; how do they currently perform these tasks? What is the workflow?
- Why do the users currently perform their tasks the way they do?
- What are the users’ information requires?
- How do users discover and correct errors?
- What are the users’ ultimate goals?
Explore different designs and approaches and get user feedback before making final direction, development, and design decisions.
Usability testing is an iterative process; it is important to conduct usability testing throughout the development cycle.
Usability testing can be conducted using elaborate labs and equipment or using relatively simple and inexpensive means. But usability testing is the only way you can know if this particular website design meets these users’requires.
This document is only an introduction; a preliminary sketch. User-Centered Web Design draws from many disciplines such as Cognitive Psychology, Anthropology, Human-Computer Interaction, Visual and Graphic Arts, Communication, User-Interface Theory, Linguistics, Human-Factors, Information Web Design, Instructional Web Design, Color Theory, Typography, and more.
Read the research in these fields. Attend conferences and seminars. Consult with specialists. Join professional organizations. Observe people’s behavior with ‘things’.
Books
Hackos, Joann T. and Redish, Janice. User Interface Task Analysis. John Wiley & Sons. 1998
Nielsen, Jacob. Usability Engineering. AP Professional. 1995
Rubin, Jeffrey. Handbook of Usability Testing. John Wiley & Sons, 1994
Sano, Darrell. Web Designing Large-scale Web Web Design: A Visual Web Design Methodology. John Wiley and Sons. 1996
Scanlon, Spool, Snyder, and DeAngelo. Web Site Usability: A Web Designer's Guide. User Interface Engineering. 1997 |
