Organizing Centers or Threads. John I. Goodlad defined the elements of scope as "the actual focal points for learning through which the school's objectives are to be at- tained."13 He wanted to convey the meaning of these elements as one term for the fol- lowing reason: Nowhere in the educational literature is there a term that conveys satisfactorily what is in- tended in these focal points. The words activities and learning experiences are used most fre- quently but are somewhat misleading. Under the circumstances there is virtue in using the technical term organizing centers. Although somewhat awkward, the term does permit the inclusion of such widely divergent focal points for learning as units of work, cultural epochs, historical events, a poem, a film on soil erosion, and a trip to the zoo. The orga- nizing center for teaching and learning may be as specific as a book on trees or as general as press censorship in the twentieth century. Organizing centers determine the essential char- acter of the curriculum.14