Fed chief Janet Yellen thinks the economic recovery will need a lot of attention and care for some time.  

Citing considerable slack in the economy and job market, Yellen said the Federal Reserve will continue making an "extraordinary commitment" to the recovery.  She projected a sustained period of low interest rates and said the Fed will continue its stimulus bond-buying program, though that effort is being scaled back.  

Yellen has been at the helm of the Fed since the retirement of Ben Bernanke in January.