Langbein, Laura Irwin. <br/><br/>
Discovering whether programs work :  a guide to statistical methods for program evaluation / 
by Laura Irwin Langbein. 
 - Glenview, Ill. :  Scott, Foresman and Company,  1980. 
 - viii, 184 p. 
 - The Scott, Foresman Public Policy Analysis and Management Series. .
<br/><br/> Includes bibliography and index. 
<br/><br/><label>ISBN: </label>0673162605 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social sciences--Statistical methods.<br/>Evaluation research--(Social action programs).