In this paper the authors extend an earlier study that developed images of what schools are like as social entities. That study found that elementary schools correspond to the rational bureaucratic image, whereas secondary schools are more loosely coupled systems. The study was limited by a small sample. In this paper the research was extended to a larger sample of schools and utilized a more extensive analytic approach. Again the finding was that high schools fall into organizational structures of the loose coupling type, and elementary schools tend to group into organizational structures of rational bureaucracies. There is evidence that it is easier to implement change in schools with relatively tight organizational structures. This suggests a basic dilemma for reform of high schools. Major reforms may require basic changes in structural arrangements, staffing, and service mix. Unless major changes are made, it seems unlikely that substantial reform will be accomplished. Included with the paper are tables and figures tabulating the data analyzed and five pages of references. (MD)