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Re: Size of a clickable area and the WCAG 2 guidelines

From: Patrick H. Lauke <redux@splintered.co.uk>
Date: Wed, 03 Mar 2010 20:55:44 +0000
Message-ID: <4B8ECCD0.8050503@splintered.co.uk>
To: "w3c-wai-ig@w3.org" <w3c-wai-ig@w3.org>
On 03/03/2010 19:43, Mike Scott wrote:
> In October 2001, Nielsen Norman Group released a study called "Beyond ALT Text: Making the Web Easy to Use for Users with Disabilities". One of their findings/recommendations was: "Avoid very small buttons and tiny text for links", noting that in their usability study, users with low vision and physical disabilities had significant difficulty with small buttons/links. Unfortunately, they did not define "small" or "tiny" or recommend a minimum size.
> For the Illinois accessibility standards (http://www.dhs.state.il.us/iitaa), we tried to develop a specific recommendation, somewhat arbitrarily arriving at 16 x 16 pixels for images and 4 or more characters for text (based on size of the smallest icons used in the typical operating systems at that time).
> In doing usability studies, we do see users struggle with small buttons/links, especially radio buttons (without labels) and single-letter links (e.g., in an alphabetical index). It would definitely be useful to have an uniform standard for minimum clickable areas.

The problem is that defining small/large in absolute terms (x pixels) is 
often irrelevant, as it doesn't take into account the size of the screen 
the users have, the resolution and dpi they're running, how close they 
are to the actual screen, the sensitivity of their pointing device...

Patrick H. Lauke
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[latin : re-, re- + dux, leader; see duke.]

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Received on Wednesday, 3 March 2010 20:56:33 UTC

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