David Warthen, co-founder of search engine Ask.com (formerly Ask Jeeves) has joined citizen journalism site Allvoices as its Chief Technology Officer.

Warthen was co-founder, and CTO for, Ask Jeeves. As Ask.com it remains the fourth most consulted search engine. It was sold to Barry Diller’s InterActive Corp for $1,85 billion in 2005. After Jeeves, Warthen acted as CTO for Eye Games, “a pioneer of full-body motion interactive webcam video games that presaged the Nintendo Wii” and Answerbag, acquired by Demand Media in 2007.

Allvoices relies on a lot of technology to do what it does. In addition to the relatively simple parts, like allowing contributors to sign up and readers to read stories, the company uses a Digg-like reader ranking system to bring stories up in the mix. It uses a complex search algorithm to verify story submissions. They also use reputation ranking to decide which contributors are the most trustworthy and they have to communicate these dynamic algorithms to users in a way that makes them useful.

“Allvoices technology is in support of the human element – where global citizens are the creators and curators of the content – to make both the site and the business model scalable,” Warthen told us. “These human/algorithm hybrid systems have been at the core of most of the work I have done, where the people involved are considered part of the system and not “outside” of the system.”

Anyone fascinated by natural language issues, or horrified for that matter, might be interested to know he intends to make it part of Allvoices.

“Applying natural language technology to the problems of the automated newsroom is very powerful,” he said. “This is an area I’m excited to bring to Allvoices’ existing team of NLP experts.”

Ask.com started as a natural language search engine but dropped that aspect eventually.

Disclosure: Lo these many years ago, I worked at Ask Jeeves when Warthen was its CTO.