Usability In The Rainforest

On the web, usability refers to the ability of users to find and use stuff on a website. (How's that for a circular definition?) According to Mel Pedley on Accessites.com, there are five core components of usability:

1. Learnability: On a first visit, can users find what they're looking for?
   
2. Effectivity: Can users do stuff quickly?
   
3. Memorability: If it's been a while since a user was on the site, can s/he still use the site?
   
4. Reliability: How error-prone are users while using the site?
   
5. Enjoyability: Do users like using the site (or, at least, do they not hate it with the burning passion of a thousand suns)?
   

Let's explore these concepts with a site we're all familiar with: Amazon.com. Sarah has been living in a rural area with ridiculously slow dial-up for the past several years, and has just discovered that you can buy products online. She needs to order a new DVD burner so she can mail her mom some home movies. She types "buy stuff online" into Google.

She sees that Amazon is the first result, and decides to click on it. (Hey, bonus points for findability!) She is then dumped onto Amazon's main page.

Okay, not a problem. Amazon's apparently a big site, which makes sense since her search query was very general. She looks around for "DVD Burners", or "Computer Components", or anything that looks like it could be what she's after. There's "Computers & Office" in the sidebar, and voila! There's "Computer Components" right there.

Lots of computer components to choose from. She remembers now why she asked her nephew for help the last time she needed to buy computer parts. Where are the DVD burners?

She scrolls down and – oh, there they are! Her nephew told her once that optical drives are the same as CD/DVD drives, so she clicks there.

She's still looking in the upper-left corner when the next page loads, so she immediately sees the link for "DVD Burners" in the navigation and clicks on it, too. No use in seeing all that other stuff she's not after.

Now that Sarah has found the DVD burners, let's evaluate how Amazon has been doing so far.

• Sarah could find what she was after with relative ease, so they get a point for learnability. (On the other hand, if she had been looking for something more obscure, she probably would have had a harder time of it.)
• She didn't have to waste a lot of time to get to where she was going, but she had the benefit of already knowing that "optical drives" and "DVD burners" were synonymous. Therefore, Amazon's effectivity was mediocre.
• This is a first-time visit, so we're not analyzing memorability.
• Sarah could easily have missed the link she needed to click on a few different times, because it was not necessarily put in a place that made the most sense. Reliability may or may not be an issue.
• So far, Sarah doesn't have a problem with using the site, so its initial enjoyability is not an issue.

What could Amazon do better? This is a hard question. One's first inclination might be to say that they should make it easier to find what people are looking for. The problem with that in this case is that because Amazon carries so many products, if they tried to make it easy to find everything, that would make their site too complex and cluttered to find anything. Burying some things three or four levels deep may be the best way to organize the information. Sometimes you have to make compromises to create the best site possible.

Accessibility Is The Path To Awesomeness

Accessibility in the context of a Web site is the degree to which that Web site is usable by people with disabilities. Web pages often have access issues for the following groups of people:

• Visually impaired people using screen readers
• Hearing impaired people using browsers with no sound
• Physically impaired people
• Color blind people (About.com, "Definition: accessibility")
  

That's one definition of accessibility in an online context. A simpler definition might be: A web site that everyone can use. That's a touch simplistic and idealistic, but it gets closer to what accessibility truly is.

There are a lot of resources out there devoted to helping web designers make their sites more accessible. The University of Minnesota, for example, has a long list of resources and tools related to accessibility. It's pretty overwhelming. About.com also has several articles about accessibility.

There's a simpler method, though, and while it's not 100% foolproof, it will get you fairly close to an accessible website. It is this: Use common sense and well-formed HTML code.

"But," you protest, "what about access keys, and alt text, and all those other things they talk about?" Remember what I said about well-formed HTML code. Images are required to have alt attributes in order for a page to validate. (Pages will still validate with blank alt attributes, though. That's where using common sense comes in: does the page still make sense without the image and without any alt text?)

Access keys (alt+[key]) are slightly different, as they are not required in valid HTML code. It also doesn't always make sense to use them. Using too many on a page can be overwhelming for a user. You also have to be careful not to use keystroke combinations that are already used for browser menus or other similar functions.

The WAVE report for the main page of Wikipedia reveals the access keys that are in use there. By my count, there are 14 different access keys, which make varying degrees of sense. Alt-F might make sense if the search field were labeled "Find articles", but it is not. Alt-U for "Upload file" does make sense, but Alt-K for "Related changes"? Another problem with using Alt-F to get to the search field is that that combination is used in nearly every Windows program to access the File menu. Firefox gets around this by adding Shift to the access key combination (Alt-Shift-F), but Safari overrides the default (Alt-F always brings up the search field).

Wikipedia does do something right, though. If you disable styles on the page, the navigation drops down to the bottom of the page. This makes it easier for people with text-only browsers or screen readers to get to the content.

Another important aspect is the color scheme. If you're planning on designing a Christmas website with red text on a green background, remember that about 5-7% of people suffer from red-green color blindness, or protanopia/deuteranopia, which would make it extremely difficult or even impossible for them to even see that there's text there. Tritanopia is another type of color blindness that affects a person's ability to see blue. One of my friends in college suffered from monochromacy and could only see shades of gray. When choosing colors, you might try using a graphics editor to convert them to grayscale and see if there is enough contrast there even without any "real" coloration.

Finally, organizing content in a way that makes sense is probably the most important step towards accessibility. Remember, you're not designing just for someone with a disability. You're designing for everyone.