Schools usually account for between 10-15 percent of the variation in pupils’ performances; and
However, some finding on effectiveness, particularly in the early years of the research, have been contradictory, e.g. high levels of staff turnover have been found to be associated with both secondary school effectiveness and ineffectiveness (Rutter et al., 1979; Reynolds, 1982; 1992). There are consistent American findings on a positive link between frequent monitoring of pupil progress and academic effectiveness, whilst Mortimore et al.(1988) found this a characteristic of ineffective schools (Reynolds, 1992)