Blind-faith investing is dead in 2009.

Market volatility has driven home to Americans the reality that they are ultimately responsible for their own investments. It also prompted backlash against giant brokerage firms that exacted sizable commissions but gave clients little to show for their money but losses last year.

Discount brokerage firms, known for lower commissions and less individual attention, continue to cut into the full-service business. While some discounters have significantly expanded their services, those offering the cheapest online trades are growing the fastest.

Consider the generational impact of the Internet: Only 17 percent of investors 63 years of age or older use online brokerages, compared with 29 percent of "Generation X" investors age 33 to 44, according to a study by Stamford, Conn., consulting firm Gartner Inc.

"The difference between full-service brokers and discount brokers is pretty clear, but the line between discount and online is getting blurry," said David Schehr, research director of industry advisory services for Gartner.

The "big five" discount brokers with online sites are Fidelity, Schwab, ETrade, Ameritrade and ScottTrade, Schehr noted, all offering trades for $15 or as low as $10. But the truly "online-dominant" group that includes TradeKing, Zecco and optionsXpress is willing to offer various types of trades at rock-bottom prices.

Fully advised investors are willing to pay for customized brokerage advice and guidance; self-directed investors want to do absolutely everything themselves; and "a bigger group in the middle" likes to execute trades on their own but would still like a little guidance.

Members of the American Association of Individual Investors ( www.aaii.com) are do-it-yourselfers who know where they stand.

"Our member surveys about discount brokerages found that price is the No. 1 concern of about 50 percent of the respondents," said Cara Scatizzi, associate financial analyst with AAII in Chicago. "Investors want a low fee because, apart from that, the brokers tend to offer the same kinds of service without much to differentiate them."

The second investor consideration is convenience, said Scatizzi, such as how easy it is to log on to the website, how fast a trade can be made and how easy it is to navigate.

"The third issue for our members involves the services offered, such as analyst reports and stock-screening tools for mutual funds," Scatizzi said.

Various performance ratings of online brokers are plentiful, with Gomez Inc. one of the leading sources. Your choice of broker depends on what you value most.

"Investors are definitely making decisions about brokers based on their online experiences," said Matt Poepsel, vice president of performance strategies for Gomez in Lexington, Mass. "Broken links or a slow overall experience will translate into whether investors decide to trust that brokerage with their money."

Gomez, known for its performance-tracking software, compiles rankings by emulating the typical contact a consumer would have with a brokerage firm. Here are its recent rankings of top online brokerages and Poepsel's explanations of each measurement:

1. Availability. "Was the investor able to log in, find the stock price for a given position and begin the trading process?" Banc of America Investment Services and ETrade tied for first place, followed by TD Ameritrade, Scottrade, TradeKing, Fidelity and WallStreetE.

2. Response time: "How long did it take to go from page to page?" Scottrade ranked first with a 3.78-second response, followed by Fidelity, ETrade, TradeKing, TD Ameritrade, optionsXpress, Banc of America Investment Services and FirstTrade.

3. Consistency: "If you were fast for investors on the West Coast but slower on the East Coast, the average time may have been OK, but that is an inconsistent performance experience." Fidelity led in consistency, with Scottrade, TradeKing, Charles Schwab, WallStreetE, optionsXpress and Wells Fargo Brokerage following.

Among full-service brokers, Smith Barney ranked first in availability, followed by UBS, Wachovia Securities and Morgan Stanley. Response-time leaders were Smith Barney, Wachovia, UBS and Morgan Stanley. Tops in consistency were UBS, Smith Barney, Wachovia and Morgan Stanley.