Abstracts - Earli

achievement is indispensable if schools are compared on this basis. Other backgroundcharacteristics like SES, ethnicity and gender may be taken into account as well. In fact,effectiveness is defined in terms of that part of the achievement not predicted by priorachievement. Goldstein (1997) has noted that in standard school effectiveness research estimatesof a school’s effectiveness are always based on its relative position in comparison with otherschools. To what extent a school appears to be effective is thus largely determined by theperformance of the other schools to which it is compared. In the UK, the attainment of literacy andnumeracy strategies at age 11 has improved substantially since 1998, but still significant variationbetween schools is found in value added analyses because these relative measures are not equal inall schools. If effectiveness were gauged using an absolute measure one would expect to find adecreasing percentage of ineffective schools and/or an increasing percentage of effective schools.The presentations in this symposium report examples of studies based on alternative researchmethods to assess the effectiveness of education.School effects on students progress: A dynamic perspectiveSimone Doolaard, University of Groningen, NetherlandsRoel Bosker, GION, Groningen University, NetherlandsHenk Guldemond, GION, Groningen University, NetherlandsSchool effects are usually within the range of 10 to 20 percent explained variance in studentoutcomes whilst controlling for intake differences between schools. The type of design usuallyemployed in this type of research is of a cross-sectional nature, with a model that has strongresemblance with the analysis of co-variance, albeit within a multilevel framework. A differentapproach, that has been advocated already in the early nineties by Raudenbush, is to look atgrowth trajectories of students, and the contributions that schools have in this respect. The presentpaper is exploring the potential of this approach. Leading questions are: 1. how much do schoolscontribute to the growth of students during primary education; 2. and are the results for languageand arithmetic comparable? 3. are contextual factors (student body composition) related to theseschool specific growth differences? To study this question a longitudinal design was employed,with students from over 100 Dutch primary schools being tested in the field of language andarithmetic. Initial explorations showed that using a logarithmic transformation of the proficiencyscores and then fitting a polynome of the second degree produced the best results. Schools thenappeared to contribute to over more than a half of the variation in language growth and to one thirdof the variation in arithmetic growth. The differences, however, relate more to the precise form ofthe trajectory rather than to the resulting differences in grade 8 performance. Further analysesrevealed that contextual effects, even when controlling for IQ-differences between students andschools, appeared to be present, although schools are given extra resources to compensate for adisadvantageous composition of the student body. Implications for future research both in the areaof school effectiveness and in the area of equal opportunities in education are discussed.Assessing school effects without controlling for prior achievement?Hans Luyten, University of Twente, NetherlandsPeter Tymms, CEM Centre, Durham University, United KingdomPaul Jones, CEM Centre, Durham University, United KingdomMultilevel modelling, which is the standard method for assessing the ‘school effect’ in educationaleffectiveness research, is combined with the regression-discontinuity approach in this study. Whilemultilevel modelling yields only estimates of relative teacher and school effects, the regressiondiscontinuityapproach allows the assessment of the absolute effect of schooling (schooling vs. no– 519 –