In his study of Canadian schools (mean teacher size 25) Andrews concluded that the use of the OCDQ is valid in both elementary and secondary schools. In this study of 36 large Illinois high schools (mean teacher size 93) Carver and Sergiovanni reveal that 72% of the schools were classified as having a closed climate. No school was placed on the open half of the climate continuum. This distribution differs greatly from that of the original Halpin and Croft study but is more in accord with the results of Watkins' study of nine secondary schools (mean teacher size 52). Carver and Sergiovanni conclude that the OCDQ is unsuited for use in large secondary schools (mean teacher size more than 25–30). With some modifications the instrument might reflect climate in large secondary schools with department chairmen as respondents.