Google ( GOOG) may be an even bigger fish in the search pond than people believe.The company dominates the search market to a greater degree than anyone has reported, controlling an "effective market share" of 90% to 95%, according to Trip Chowdhry, a managing director at Global Equities Research. Using a different methodology, leading industry researcher ComScore, which released figures Monday for traffic trends in December, placed Google's market share at a 47.3%, compared with second-place Yahoo!'s ( YHOO) 28.5%. Chowdhry arrived at the figure by asking industry contacts to tally their access logs, which show how a user landed on a particular Web site. ComScore, on the other hand, reports the data that it extrapolates from the roughly 2 million Web surfers around the globe who allow the research firm to peer into their Internet browsing habits, says Gian Fulgoni, ComScore chairman. ComScore's method counts those searches launched on an engine as part of the market-share figure, even if the user does not click through to arrive at a Web site pulled up by the results. Though the approach may be a good way to gauge browsing behavior, it is less important in assessing the type of market share that's important to investors, contends Chowdhry. Looking at how users actually arrived at a Web site, instead of what they may have initially entered on a search engine, is more important because it offers clearer insight into how ad dollars -- and the associated revenue for the different engines -- will be allocated.