Much has been written about school effectiveness over the last two decades and there now exists a wealth of research evidence that describes the features or characteristics of effective schools in some detail (Mortimore et al. 1998 Sammons et at. 1998). In addition, the school effectiveness field has highlighted the contribution of departmental effectiveness to whole-school effectiveness. Research in this area has shown that a substantial proportion of the variation in effectiveness among schools is due to variation within schools, particularly at the departmental level (Creemers 1994; Fitz-Gibbon 1992).