The company has confirmed the appointments of Scott Prevost to the position of VP of product management on search and Dennis DeCoste to the position of director of research, where he will manage such technical topics as data mining and machine learning.

Prevost will start immediately. DeCoste is a couple of weeks into his new job.

The two hires will focus on delivering changes to the e-commerce site’s homegrown search engine, by better matching items in its inventory based on a consumer’s search terms or interests.

The company is now working on the next-generation of search, according to the company’s research labs, which lists both “search” and “machine learning” as two of its top priorities. Recently, eBay rolled out the ability to sort by “Best Match,” and will soon be launching other versions on eBay.com. “Through great strides we’ve made in applying machine learning to our search engine, search results will continue to become more relevant with each use,” says a labs post.

Previously, Prevost was the principal development manager at Bing, where he led a team of developers who were responsible for a bringing a variety of Bing features to market, including complex stuff like adding “captions and summaries to search results, reference answers and query processing using natural language techniques,” according to Prevost’s LinkedIn profile. Before that, he served as the general manger and director of product for Powerset, which Microsoft acquired in 2008.

Before joining eBay, DeCoste was a research scientist at Facebook, where he worked to improve a number of products, including ad matching, search ranking, link recommendation and spam detection. Prior to that, he was a principal scientist at Microsoft and a director of research at Yahoo Research, according to his profile on LinkedIn.

We also reported exclusively today that eBay’s PayPal subsidiary has hired Sarah Brody, formerly at Apple, to lead Global Design.

Bill has definitely not retired for us.”

– Scott Prevost, general manager and product director at Powerset, the semantic search start-up Microsoft recently acquired, says reports of Chairman Bill Gates’s retirement have been greatly exaggerated.