Recent reports suggest the accessibility of many public and private sector web sites falls short of World Wide Web Consortium (W3C) standards.

Research by user experience consultancy Designed for All last month found that only 30 percent of web sites displaying an accessibility statement or logo were making accurate claims about accessibility. Many of their sites failed basic accessibility tests or claimed standards beyond those actually achieved, according to the firm's report.

In separate Cabinet Office research released at the end of last year, only three percent of 436 public service web sites examined across Europe were found to meet the internationally accepted W3C web accessibility standards.

Mike Davis of analyst firm Butler Group blamed firms' poor management for not picking up such failings during testing. "When government departments put together web sites, priority is not given to accessibility issues," Davis said. "Compliance to these standards should be in every specification [for government sites]."

Jennifer Axelrad, marketing manager for speech-recognition technology specialist Nuance, said, "I'm surprised the figure [for good accessibility was as high as] three percent. It is a disgrace considering how easy it is to implement accessibility systems - the technology is out there and it's not difficult to do."

Robin Christopherson of web accessibility specialist AbilityNet, which carried out the Cabinet Office survey with a number of other organisations, said that public sector sites are usually more accessible than others. "[These findings] are something of a mystery. We were very rigorous in our methodology but even taking that into account, it is still much worse than expected," he said.

Although separate figures for the UK were not available, Christopherson noted that countries tend to fare better if they have a high "index of engagement", as the UK does. This means there are laws requiring accessibility for sites, and a recognised body in charge of accreditation systems, he explained.

Under the UK's 1999 Disability Discrimination Act it is an offence for major commercial and public sector sites to be inaccessible to disabled people, yet many government sites are still falling short.

"In the first three or four years it was probably a substantial enough defence to say you didn't even know [the act existed]," Christopherson said. " There were very few access-checking tools, few consultants to help and a general lack of knowledge, so the Disability Rights Commission gave companies a large period of grace."

He added that many web site designers do not have the knowledge to construct adequately accessible web sites and there is still a shortage of good tools and materials to help. "The sort of fluid design [needed to create standards-compliant web sites] is out of the comfort zone of your average designer," Christopherson said.

Nuance's Axelrad added that in the private sector too, many sites fail to meet accessibility standards, even though there is a strong business case for compliance.

It is widely accepted that easily accessible web sites are simpler and cheaper to maintain, as they are not bloated with unnecessary code. And they are also likely to attract more online customers. According to AbilityNet, sites that follow good practices for accessibility are 35 percent easier to use for everyone.