This study evaluated the Philadelphia Affective Education Development Program (AEDP) as it affected student relationships within the classroom and student perceptions of the classroom climate. The differences between four AEDP and four regular English classes from one high school were determined in regard to (1) sociometric structure as analyzed in terms of Schmuck's concepts of centrality and diffuseness; (2) classroom climate as determined by student responses to the Learning Environment Inventory scales for friction, cliqueness, disorganization, apathy, goal direction, satisfaction, and democracy; and (3) the ability of the class to plan and work together as measured by the Russell Sage Social Relations Test for group problem-solving. The classes were not significantly different in sociometric structure or in the areas of friction, cliqueness, disorganization, and goal direction. The AEDP students tended to view their classes as higher in satisfaction and democracy and lower in apathy than did regular students, and they were more able to plan and work together as a class. No significant correlation was found among diffuseness of classroom sociometric structure, classroom climate, and the ability of students to plan and work together as a class. (TO)