CHICAGO —  Retiring Supreme Court Justice Sandra Day O'Connor (search) is taking on a new challenge: overseeing a national civics lesson.

Many adults struggle to identify the branches of government — legislative, executive and judicial — and explain the concept of separation of powers, according to a new American Bar Association poll.

Michael Greco, a Boston lawyer who takes over as ABA president this week, asked O'Connor and former presidential candidate and Sen. Bill Bradley (search), D-N.J., to help educate people on the subject. They will be honorary co-chairs of a civic education commission.

The ABA poll, being released Monday, shows that just over half of adults can correctly identify the branches.

One in five incorrectly said that the three branches were Republican, Democrat and independent, and 16 percent thought the three were local, state and federal.

While eight in 10 people said that separation of powers (search) is important, less than half, when given four choices, correctly picked that "Congress, the president and the federal courts each have different responsibilities." Nearly a third said it meant different federal departments have different powers.

"There are some significant gaps in people's knowledge," Greco said.

O'Connor, 75, served as an Arizona state senator and judge before President Reagan named her to the Supreme Court in 1981.

Her retirement, announced last month, provides its own civics lesson. Under the Constitution, Supreme Court justices (judicial branch) are named by the president (executive) but must be confirmed first by the Senate (legislative).

The poll of 1,002 adults was conducted July 22-27 by Harris Interactive. It has a margin of sampling error of plus or minus 3 percentage points.