Online airfare predictor has mixed results in test

Farecast.com, the travel search engine that attempts to predict where airfares are headed, was on target roughly half the time in a Globe sampling.

Last Sunday's Consumer Beat listed Farecast's lowest available fare to five destinations from Boston alongside the website's prediction about where those fares would head over the next seven days.

I followed up to see how accurate Farecast's predictions were. Twice the website accurately predicted price increases, but twice it missed the boat, once predicting an increase when the fare dropped and once predicting a decrease when the fare went up.

On the fifth route, from Boston to Philadelphia, Farecast was fairly close . The website predicted the lowest fare would drop $6 over the next seven days, but it stayed the same.

One of Farecast's predictions was amazingly close. The lowest fare from Boston to Los Angeles was forecasted to rise $50 to $447. It rose $52.

For a trip to Baltimore, Farecast got the trend line right but was off a bit on the amount. The website predicted the lowest fare would rise $28 to $162, but the fare rose $41.

Farecast missed the mark on fares to Las Vegas and Seattle. It predicted the $447 fare to Seattle would drop by $50 over the next seven days, but the fare increased $25.

Farecast also predicted the $397 fare to Las Vegas would rise $50, but the fare actually declined $26. In Farecast's defense, its confidence level on the Vegas prediction was only 50 percent, well below the 80 percent confidence level of the other forecasts.

Hugh Crean , Farecast's chief executive, said the company's predictions are based on an average price over the next seven days. The Globe compared only the price on the day of the search and the price seven days later.

Aside from the methodology issue, Crean said: ``It looks like we had low confidence on the Boston-Vegas search, and we were off in a highly volatile Seattle-Boston search," he said.

Farecast is trying to break into the crowded travel-search category by presenting a comprehensive list of flights and fares and advising travelers to buy or wait based on its price predictions. Farecast is about to open to the public, but just for flights from Boston and Seattle. It expects to steadily add originating airports and go national by the end of the year.

Bruce Mohl can be reached at mohl@globe.com.