Without doing their homework, most Philadelphia Democratic voters will face a nearly impossible task on May 15 in making nominations for four vacancies on the city's Court of Common Pleas.

They'll find a ballot crowded with 15 candidates, virtual unknowns outside legal circles. Left to their own devices, voters could pick based solely on the seeming ethnicity of surnames, gender, or ballot position.

Voters can improve their choices, of course, by reading up on the candidates and checking the Philadelphia Bar Association's "recommended" ratings. (See http://go.philly.com/judges.)

As always, the Editorial Board offers its choices. From among many able candidates for the Democratic nomination, four stand out:

ELLEN GREEN-CEISLER is everything you would want in a judge - smart, independent, gutsy. How else could this former city prosecutor and investigative TV producer (not to mention soccer mom) have served so ably as the Police Department's civilian oversight officer and yet earned the endorsement of the Fraternal Order of Police?

Green-Ceisler, 49, probed the shortcomings of police discipline, urging common-sense reforms. She donned a bulletproof vest to learn firsthand about policing. Just as when she audited the school district last year, Green-Ceisler stands her ground when pushing for change in entrenched bureaucracies. Making her second run, Green-Ceisler is even more seasoned, having recently worked as the City Controller's special investigations chief.

GREG COLEMAN, 59, will be an imposing presence on the bench, with his deep voice and dignified manner. Not that there's anything wrong with that in a judge. The son of the first African American City Council president - who served his father as chief of staff - Coleman has run a varied private practice in recent years. He's a specialist in mental-health law, with a Rutgers law degree. He's done bond work and holds a real estate broker's license. Chess is a passion. Voters' next smart move would be to nominate Coleman.

MICHAEL ERDOS, 42, has helped rid city neighborhoods of drug houses and nuisance bars during a decade as a city prosecutor. That may be a world away from his Yale law studies and Oxford University undergraduate work, but it shows the breadth of experience this college athlete (hoops) would bring to the bench.

BEVERLY MULDROW, 57, a Franklin & Marshall grad with an Ohio State law degree, also spent 10 years with the District Attorney's Office and three with the Environmental Protection Agency. She was a corporate counsel before launching a varied private practice in 2001. She has the right temperament and legal background to be an asset on the bench.