Few people would question the internet’s importance as an educational tool, but a new study suggests the ephemeral nature of web pages can pose significant challenges for educators.

According to research done by two university professors who tracked the existence of web pages used in their online science courses, almost one in five science education web links becomes extinct within two years.

“We were surprised by this steady decline,” said John Markwell, a professor of biochemistry at the University of Nebraska in Lincoln. Educators can spend hours searching for appropriate online content online to build into their lessons, he said, only to find at the worst possible time a broken link, or worse.

“I was very optimistic about using internet links two years ago. I’m less optimistic now,” Markwell said.

Markwell and his colleague David Brooks, a chemistry education professor, developed three online biochemistry science courses for high school teachers in the summer of 2000. Instead of creating a lot of original content, they decided to link to existing internet web pages where possible.

However, when students began using the courses the following September, they noticed many web links were no longer active or the content had changed. Flustered by so many broken web links, the researchers decided to formally track the 515 web links used in their online courses.

The study, entitled “Broken links: The ephemeral nature of educational WWW hyperlinks,” will be published in the June issue of the Journal of Science Education and Technology. Over time, the researchers assert, most web links gradually disappear.

“About 12 percent [of dot-edu web links] were gone in the first year,” Markwell said. “After 20 months, almost 19 percent of the links were gone.”

The rate of disappearance was even higher for dot-com web links: nearly 43 percent were gone within two years.

Based on the data collected so far, the researchers estimate that half of the science education web links they selected for their online courses will be broken in approximately 55 months, or four and a half years.

“The disappearance is one frustrating part. The second part is that the web sites change over time,” Markwell said.

Links often become broken when web site operators restructure their web sites, change material, or go out of business. And some links now lead to advertising or pornography sites. The demise of so many dot-coms also contributed to the number of broken links, Markwell said.

Markwell recommends that educators and online course developers get permission to mirror a web site rather than linking to it. If the site’s operator is aware that you are mirroring its web site, then the operator can let you know when the site has been updated so you can adjust the mirrored version accordingly, he said.

Markwell said he and Brooks hope to expand their research to track the frequency of broken links among 5,000 web pages.

As a solution to this problem and as a free service for educators, Markwell said he’d eventually like to create a web page where teachers could submit important links, and the site would monitor the links and report any changes to the teachers. Markwell said he has applied for a grant from the National Science Foundation to develop this technology, but he won’t know whether his proposal for funding is approved until this summer.

Some schools have taken creative steps to solve the problem. Sandra Becker, director of technology for the Governor Mifflin School District in Pennsylvania, said teachers in her district used to panic when they would encounter broken web links during a lesson, so the district began addressing this problem in workshops.

“We have a web site for students with recommended links as a fallback for staff in varied curricula,” Becker said. If a teacher’s lesson plans are thrown off by a broken web link, she can direct students to appropriate internet resources on the district’s fallback page.

Links:

Broken Links: Just How Rapidly Do Science Education Hyperlinks Go Extinct?
http://www-class.unl.edu/biochem/url/broken_links.html

Journal of Science Education and Technology
http://www.gse.harvard.edu/~etc/jset

Governor Mifflin School District
http://www.gmsd.k12.pa.us