- From: John Foliot - WATS.ca <foliot@wats.ca>
- Date: Fri, 12 Aug 2005 08:18:45 -0400
- To: <lois@lois.co.uk>, <w3c-wai-ig@w3.org>
Lois Wakeman wrote: > Rebecca, > At the risk of teaching you to suck eggs, would you not be able to > gauge an approximate answer to your question by attempting to > navigate some sample menus using Lynx, for example - and see how you > get on? > FWIW, I think partially-concealed dynamic menus are pretty hopeless in > usability/IA terms, as you can so easily lose the context. It is > debatable as to how useful real people find complex and exhaustive > navigation schemes - even though designers often love them as a way > of avoiding doing the IA analysis properly ;-) > Lois Wakeman > ------------------------- > http://communicationarts.co.uk > http://lois.co.uk [As referenced in my earlier post, but re-printed here:] While I do appreciate that certain times and instances would warrant consideration of a flyout menu, developers *must* be reasonable in the application of this type of technique. Using multiply nested lists that "compact" via CSS and/or JavaScript may visually help visual users, however we must all understand that for some users, too many choices is confusing at best, and may in fact cause "failure" in their quest. How much is too much? Wish I had a definitive answer. But *I do* know when there is too much... But it's an instinctive reasoning, rather than hard science - just like knowing what is "appropriate" ALT text. My acid test is this - can I remember all of the options available once I've been exposed to them all? How many *can* I remember? Some studies[1] have suggested that the "Magic Number" of 7 (+/- 2) is a reasonable number to work with - but does that mean 7 lists of seven options? Visually impaired users I know would argue that having an initial 49 navigational choices would be too many - especially if they were arriving at a site for the first time. In a 1997 CHI (Computer Human Interface) paper [2], it was noted, "The basic insight is that, in order to navigate through a world with minimal prior knowledge of its layout, .... that they [developers - JF] shall not overwhelm the user with information. In particular for view navigation, Furnas showed that it is ideal to show only small views (a relatively small number of choices) that the number of navigation steps is not too large and that the route to any target must be discoverable." A Microsoft study [1.2] demonstrated that accuracy diminished as more "sub-levels" (hierarchy) were added (in other words one nested list inside the master list is preferred over a list inside of a list inside of a list). However, George A. Miller (the original author of "The Magical Number Seven") noted "The point seems to be that, as we add more variables..., we increase the total capacity [of differentiation - JF], but we decrease the accuracy for any particular variable.."[1.1] Now I ain't no CHI expert - but clearly these guys have research backing up my assertion - too many initial choices hinders rather than helps. It seems that you *can* have more than 7, but the more you add, the less accurate the end user's results become; so at what point do we "turn the corner"? Sadly, there still seems to be no "definitive" answer as to "how many?". Like many of the choices we make, it all depends... *** The other significant issues are that of mobility impairments and alternative user agents. Tightly packed hyperlinked objects can cause issues for users who lack fine motor coordination, either due to some form of disability, age (too young or too old?) or simply because the user agent and/or input tools they are using cannot provide the required finesse. (Some people like those trackball thingies, or touchpads - I don't like either...) So, if you *really* must employ flyout menus, do so with caution and prudence - they cannot become the collapsing site map present on every page, as this will simply defeat any positive effect you are striving for. As well, I would caution any developer who is *mandated* to achieve a certain level of compliance to any of the "standards" (be it Section 508 or A, AA, AAA) that due to the cognitive load issue you *may* not be in compliance - blanket claims of any of the pre-packaged (or even "roll-year-own") solutions not-withstanding: WAG Priority 2 - 12.3 Divide large blocks of information into more manageable groups where natural and appropriate. WAG Priority 3 - 9.4 Create a logical tab order through links, form controls, and objects. WAG Priority 3 - 13.6 Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group. JF -- John Foliot foliot@wats.ca Web Accessibility Specialist / Co-founder of WATS.ca Web Accessibility Testing and Services http://www.wats.ca Phone: 1-613-482-7053 [1.1] The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information (http://www.well.com/user/smalin/miller.html) [1.2] Is the Magic Number 7 Relevant to Web Page Design (http://research.microsoft.com/users/marycz/chi981.htm) [2] Effective View-Navigation. Human Factors in Computing Systems CHI '97 Conference Proceedings, New York, NY: ACM Press (http://www.interaction-design.org/references/conferences/proceedings_of _the_acm_chi_97_human_factors_in_computing_systems_conference.html - requires subscription)
Received on Friday, 12 August 2005 12:19:06 UTC