David Guryan , Jens Ludwig : Growth rate for big urban schools about 50 % . Many believe academic learning not feasible when disadvantaged kids are 16 years . They say program of small - group tutoring raised students ' performance considerably . But most urban school systems struggle with the costs of having one teacher in a room with 25 ( or more ) students ; how could we ever have a class size of just one or two students per instructor ? Writers : It worked in Chicago , why not elsewhere ? It is not to give up with teens .
David Guryan , Jens Ludwig : Growth rate for big urban schools about 50 % . Many believe academic learning not feasible when disadvantaged kids are 16 years . They say program of small - group tutoring raised students ' performance considerably . Writers : It worked in Chicago , why not elsewhere ? It is not to give up with teens .