28-Jun-15 HTML Style Bloopers

2 What is good style? Good style, like good taste, is partly--but only partly--a matter of opinion Bad style is frequently easier to define A web page has bad style if You can’t load the page You can’t use the page for its intended purpose You can’t read the page You can’t adjust the page to your needs You can’t get rid of the page You can’t navigate the site containing the page

3 Cannot load the page Macromedia Flash is the worst offender Pages containing Flash animations often cannot even be loaded by browsers without Flash If you are going to use Flash, or other fancy features, make sure your intended audience has the ability to see your pages

4 Cannot use the page Many users turn off automatic image loading They may have a slow connection They may be visually disabled If your only hyperlink to another page is through an image, users without images cannot get there Always provide text hyperlinks in addition to your images To submit a form via HTML, you usually must have JavaScript turned on The JavaScript does client-side input checking This is probably useful enough to justify requiring JavaScript, but be sure your users are aware of the requirement

5 Cannot use with new technology Many “telephones” can access the Web Blackberry is the best known (and most expensive) Mine is a T-Mobile Sidekick My Sidekick does not do JavaScript I can’t get flight information from the Philadelphia airport I can’t access some weather sites Some sites are useable but very cluttered (e.g. Amazon) For the most useful sites, alternative sites have come into existence

6 Cannot read the page Here are two otherwise very nice backgrounds: Both of these backgrounds have text--can you see it?

7 Still cannot read the page Have you seen pages that tell you what browser to use and what to set your screen size to? Did you ever do it? What do you think about that person’s ego? This page was created by someone with perfect eyesight using a 21-inch monitor set to 1600 by 1200 resolution, using an 8-point serif font, and as a result nobody but the original author has a clue what it actually says. Some people just like to use weird fonts 7% of white males are red-green colorblind There are lots of places you can use absolute measurements in HTML, and very little reason ever to do so

8 Contrast is important Use either very dark text against a very light background or very light text against a very dark background Avoid contrast in the background itself If it has good contrast on your monitor, that doesn’t mean it will have good contrast on everyone else’s Always use more contrast than you think necessary The ability to read depends on edge detection Human edge detection relies on contrast--differences between light and dark--not on color differences This is a difference in color, not in contrast

9 You can’t adjust the page Pages that use absolute sizes--for example, to adjust the size of a table to just fit on a 17-inch screen--are a serious nuisance Scrolling vertically is acceptable, because we don’t need to scroll often to read a column of text If we need to scroll sideways, we need to scroll back and forth for every single line Relative sizes don’t always work, either; I’ve run across pages containing tables that are 110% of the page width Even if your monitor is large and your eyesight is good, there may be other things on the screen that you want to see

10 You can’t leave the page Sometimes this occurs through malice--the page includes JavaScript to pop up a new window each time you close the current one Usually it’s an accident: a page gives you an automatic transfer to a new page, but with the time set to zero: This takes you to the new page but effectively disables the “Back” button

11 You can’t navigate the site EPSON has long been my favorite example Suppose you want to download a printer driver; you go to and here are your choices: Printers & Imaging products Electronic devices Point of Sale Products This represents their corporate organization What do I care how they are organized?

12 Workarounds Poor contrast: Hit control-A, to select all the text on the page Otherwise, in Preferences, select “Use my chosen colors” and/or turn of image loading, then reload page Bad size: Increase or decrease screen resolution Can’t leave the page with the Back button Use the pull-down list of pages you’ve been to Can’t navigate the site Use Google

13 The End