Websites suffer high decay factor

Websites should have a 'best before' date of three months, if a recent report into the 'freshness' of the web is anything to go by.

According to an experiment carried out over the last year, content on the web suffers a 60, 70 and 80 per cent decay rate at three, six, and 12 month intervals respectively.

Essentially, this means that over half the web is out of date after three months.

The research was published by geek site Slashdot this morning and suggests that, if a company wants to maintain a freshness rate on par with the web as a whole, its website content should be updated at the inverse rate.

"In other words 60 per cent of the site should change every three months, 70 per cent should change every six months, and 80 per cent should change every 12 months," it said.

"The only way to do this effectively is to either have a very small site, or have a site with dynamically generated information."

Scott Ennis, who conducted the research, searched Google for a variety of English phrases at various time points to determine a baseline for the common rate of freshness of overall web content.

Ennis selected the following phrases because of their "unique characteristics".

'Life's short play hard' had the greatest decay rate of any phrase searched. One for the Monty Python fans, 'Blessed are the cheesemakers', produced relatively small results, but "demonstrated that quantity of pages may not be important in determining decay rate", according to Ennis.

'Late at night' returned the highest number of results yet also adheres closely to the 60, 70, 80 per cent rule.

And finally, 'Bill Gates sucks' which, perhaps unsurprisingly, had the lowest decay rate of any phrases searched.

Ennis concluded that web content decays at a uniform, determinable rate and that sites wanting to optimise their content freshness need to maintain a rate of freshness that corresponds to the rate of web decay.

The research follows on from a similar study on 'link rot' published last month.

It revealed that at any one time around 30 per cent of hyperlinks on the web don't work. This means that almost a third of the web consists of the dreaded '404 error: page not found'.

In light of such research, the godfather of the web, Tim Berners-Lee, has put forward proposals for a self healing, or 'semantic', web.

"There are no reasons at all in theory for people to change URLs, or stop maintaining documents," he said. "But there are millions of reasons in practice."