- From: Graham Oliver <graham_oliver@yahoo.com>
- Date: Mon, 27 Aug 2001 22:08:12 +0100 (BST)
- To: Paul@ten-20.com, w3c-wai-ig@w3.org
Hi Paul 'Partially sighted readers prefer non-serif fonts' p 59 'Site Seeing' by Eric Velleman and Henk Snetselaar both of the Bartimeus Educational Institute. Also see this page http://wsupsy.psy.twsu.edu/surl/usabilitynews/2S/font.htm which covers font research on people without a visual impairment (as far as I can tell). Note the dangers they highlight of using 10 point (or less) serif fonts. <Extract> Yet, as seen in Figure 4, other than the 12-point TNR font, the TNR fonts were the least preferred. One reason for this could be that at smaller font sizes on computer screens, the serifs stop acting as distinguishers and start becoming visual 'noise.' Moreover, small anti-aliased fonts may create even more visual noise because of the smoothing effects of the anti-aliased font. This would explain the very poor performance of the 10-point anti-aliased TNR font. </Extract> Here is something I put together on font size and enlargement issues which are vital for people with a visual impairment <Font Size Enlargement Info> Font size can be specified using the FONT element in HTML or using the font-size property in CSS. The rationale for not using the FONT element is that it increases maintenance costs, has been deprecated in HTML 4.01, doesn't allow the user to control font size using personal style sheets and is less flexible than the font-size property in CSS. The following considers the strategy to follow to allow enlargement of text, given that CSS are used to implement font size. There are 4 possibilities to specify font size: -Absolute Size The keywords used to express font size range from 'xx-small' to 'xx-large' -Relative Size The keywords used to express font size are 'smaller' and 'larger' -Height Height can be expressed in a number of units, including points (pt), pixels (px), ems (em) and inches. -Percentage A percentage font size as a percentage of the parent font size. Although both Absolute and Relative Size fonts do enlarge, they are implemented differently across browsers. Their use would serve to overly restrict design decisions and usability. The only Height unit that allows enlargement in Internet Explorer is the 'em'. The Percentage unit also allows enlargement. Thus, the use of either the 'em' or the '%' unit is recommended to allow enlargement of text. </Font Size Enlargement Info> Cheers Graham Oliver ===== 'Making on-line information accessible' Mobile Phone : +64 25 919 724 - New Zealand Work Phone : +64 9 846 6995 - New Zealand AIM ID : grahamolivernz ____________________________________________________________ Do You Yahoo!? Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk or your free @yahoo.ie address at http://mail.yahoo.ie
Received on Monday, 27 August 2001 17:08:15 UTC