The Class Size Controversy

[Excerpt] When we ask whether class size matters for achievement, it is essential to ask also, how class size matters. This is important for three reasons. First, if we can observe not only achievement differences, but also the mechanisms through which the differences are produced, this will increase our confidence that the differences are real, and not an artifact of some unmeasured or inadequately controlled condition. Second, the effects of class size may vary in different circumstances, and identifying how class size affects achievement will help us to understand why the effects of class size are variable. Third, the potential benefits of class size reduction may be greater than what we observe. For example, suppose class size reductions aid achievement, but only when teachers modify instructional practices to take advantage of the smaller classes. If a few teachers make such modifications, but most do not, then understanding how class size affects achievement in some cases will help reveal its potential effects, even if the potential is generally unrealized

Class Size and Class Heterogeneity

We study how class size and composition affect the academic and labor market performances of college students, two crucial policy questions given the secular increase in college enrollment. We rely on the random assignment of students to teaching classes. Our results suggest that a one standard deviation increase in the class-size would result in a 0.1 standard deviation deterioration of the average grade. Further, the effect is heterogenous as female and higher income students seem almost immune to the size of the class. Also, the effects on performance of class composition in terms of gender and ability appears to be inverse U-shaped. Finally, a reduction of 20 students (one standard deviation) in one's class size has a positive effect on monthly wages of about 80 Euros (115 USD) or 6% over the average.class size, heterogeneity, experimental evidence, academic performance, wages

Classroom contexts: Connections between class size and within class grouping

Background. There has been a vigorous debate for many years about the educational effects of class size differences, but even if differences have an impact on pupils' academic progress this still leaves unanswered important questions about what mediates the effect. Aims. This paper is informed by a classroom contextual perspective, and examines associations between class size and within class groupings (in terms of size and number of groups, adult presence in groups, and type of interaction between grouping members). Age differences in these relationships are also explored. Samples. The quantitative study is based on analysis of 3157 groupings, from 672 Reception, Year 2 and Year 5 classes in 331 schools. The qualitative study was based on 12 classes in 8 case study schools, and questionnaire responses completed by over 100 class teachers. Methods. Links between size of class and within class groupings were examined on the basis of a 'grouping mapping survey', in which teachers at a given time in the school day provided information on group size and number, adult presence, and type of interaction between pupils, and complementary qualitative analyses of data from teacher-completed questionnaires, and interviews. Results. The number of groups in a class increased with the size of the class. Over all three year groups, small classes had on average just over three groups, while large classes approached six groups. The size of groups in the class decreased with size of class. In class sizes over 25, pupils were more likely to be in a large group of 7-10, while in classes under 25 they were more likely to be in whole class groupings. Qualitative analyses showed that teachers felt that groups of 7-10 pupils had negative educational effects, for example, in terms of the quality and quantity of teaching and children's concentration and contribution in groups. Conclusions. Results suggest that the effects of class size can be best seen as through the size and number of groups, which will then have implications for learning experiences. So while debate about size of class has often been in terms of reduced size of class resulting in pupil academic gains, it is also important educationally to consider within class grouping size and number, and their effects.link_to_subscribed_fulltex

Uniquely-Wilf classes

Two permutations in a class are Wilf-equivalent if, for every size, $n$, the number of permutations in the class of size $n$ containing each of them is the same. Those infinite classes that have only one equivalence class in each size for this relation are characterised provided either that they avoid at least one permutation of size 3, or at least three permutations of size 4.Comment: Updated to DMTCS styl

Long-Term Effects of Class Size

This paper evaluates the long-term effects of class size in primary school. We use rich administrative data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are not only beneficial for cognitive test scores at age 13 but also for non-cognitive scores at that age, for cognitive test scores at ages 16 and 18, and for completed education and wages at age 27 to 42. The estimated effect on wages is much larger than any indirect (imputed) estimate of the wage effect, and is large enough to pass a cost-benefit test.educational attainment, non-cognitive skills, cognitive skills, regression discontinuity, class size, earnings

Heterogeneous Class Size Effects: New Evidence from a Panel of University Students

Over the last decade, many countries have experienced dramatic increases in university enrolment, which, when not matched by compensating increases in other inputs, have resulted in larger class sizes. Using administrative records from a leading UK university, we present evidence on the effects of class size on students’ test scores. We observe the same student and faculty members being exposed to a wide range of class sizes from less than 10 to over 200. We therefore estimate non-linear class size effects controlling for unobserved heterogeneity of both individual students and faculty. We find that (i) at the average class size, the effect size is -0.108; (ii) the effect size is however negative and significant only for the smallest and largest ranges of class sizes and zero over a wide range of intermediate class sizes; (iii) students at the top of the test score distribution are more affected by changes in class size, especially when class sizes are very large. We present evidence to rule out class size effects being due solely to the non-random assignment of faculty to class size, sorting by students onto courses on the basis of class size, omitted inputs, the difficulty of courses, or grading policies. The evidence also shows the class size effects are not mitigated for students with greater knowledge of the UK university system, this university in particular, or with greater family wealth.class size, heterogeneity, university education

Review of The Impact of a Universal Class-Size Reduction Policy: Evidence from Florida's Statewide Mandate

A new Think Twice review released today finds that a recent report on the effect of Florida's class-size reduction reform on student achievement does not actually study the impact of class-size reduction.The Impact of a Universal Class-Size Reduction Policy: Evidence from Florida's Statewide Mandate, written by Matthew M. Chingos for the Program on Education Policy and Governance at Harvard University's Kennedy School, was reviewed for the Think Twice think tank review project by Professor Jeremy Finn of the University at Buffalo-SUNY. Finn, a statistics expert, was a lead researcher of Tennessee's Project STAR, a large, randomized experiment in class-size reduction (CSR). In 2002, Florida voters passed a constitutional amendment mandating CSR throughout that state's schools.The Chingos study compares student test scores in districts that already had average class sizes smaller than required by the amendment with student scores in districts with average class sizes larger than required by the amendment. Districts that already had smaller class sizes received the same additional funding but could use the money as they saw fit, while those with larger class sizes were required to use the state CSR funds to reduce class sizes. Chingos concludes that "mandated CSR in Florida had little, if any, effect on cognitive and non-cognitive outcomes" in the students examined. Finn, however, points out that the study doesn't actually address the effect of CSR on student achievement. Instead the study compares the results of schools that reduced class size with a group of schools that received monies to use as they wished. Both sets of districts in the study had small class sizes. According to Finn, the study's finding would more accurately be stated as "administrative discretion in spending state class-size reduction funds did not affect students' academic performance."Finn's review also points out that there are other flaws in the Chingos study: It uses the broad brush of school and district averages rather than student-level information about class sizes and test scores. Also, the actual class-size differences between the two groups were too small to make an educational difference; both of the groups had small average class sizes.Finn concludes, "Despite its title, this report does not address the issue of class-size reduction. By being presented as an evaluation of Florida's mandated class size limits, it may lead parents, educators, or policy makers to draw faulty conclusions about the impact of the program.

Class Size and Nursing Students\u27 Perception of Empowerment

Due to increases in enrollment and budget cuts in many states, college class sizes are reaching unprecedented sizes (Carpenter, 2006). Nursing schools are facing the same challenges. Only limited research has been conducted on the effects of class size on nursing students\u27 perception of empowerment Conger (1989) defines empowerment as the act of reinforcing one\u27s belief in his or her perception of competence. Empowerment is important for nursing students\u27 education (Chally, 1992). To achieve the optimal learning experience in face of increasing class size, it is important to explore how nursing students experience learning in both small and large class environments. This study surveyed 71 BSN students enrolled in both small- and large-size classes on their perceptions of empowerment The study\u27s findings showed statistically significant differences in favor of smail classes positively impacting the students\u27 perceptions of empowerment and the quality of their individual learning experiences

New Evidence on Class Size Effects : A Pupil Fixed Effects Approach

The impact of class size on student achievement remains a thorny question for educational decision makers. Meta-analyses of empirical studies emphasise the absence of class-size effects but detractors have argued against such pessimistic conclusions because many of the underlying studies have not paid attention to the endogeneity of class-size. This paper uses a stringent method to address the endogeneity problem using TIMSS data on 45 countries. We measure the class size effect by relating the difference in a student’s achievement across subjects to the difference in his/her class-size across subjects. This (subject-differenced) within-pupil achievement production function avoids the problem of the non-random matching of children to specific schools, and to classes within schools. The results show a statistically significant effect of class size for 16 countries but in only 10 of them is the effect negative, and the effect size is very small in most cases. Several robustness tests are carried out, including control for students’ subject-specific ability and subject-specific teacher characteristics, and correction for possible measurement error. Thus, our stringent approach to addressing the problem endogeneity confirms the findings of meta-analyses that find little support for class size effects. We find that class-size effects are smaller in resource-rich countries than in developing countries, supporting the idea that the adverse effect of larger classes increases with class-size. We also find that class size effects are smaller in regions with higher teacher quality.

Are Class Size Differences Related to Pupils' Educational Progress and Classroom Processes? Findings from the Institute of Education Class Size Study of Children Aged 5-7 Years

Despite evidence from the USA that children in small classes of less than 20 do better academically there is still a vociferous debate about the effects of class size differences in schools, and considerable gaps in our understanding of the effects of class size differences. This article summarises results from the most complete UK analysis to date of the educational consequences of class size differences. The study had two aims: first, to establish whether class size differences affect pupils' academic achievement; and second, to study connections between class size and classroom processes, which might explain any differences found. The study had a number of features that were designed to be an improvement on previous research. It used an 'observational' approach, rather than an interventionist one, in order to capture the nature of the relationship between class size and achievement across the full range of observed classes, and it employed a longitudinal design with baseline assessment to adjust for possible non-random selection of children into classes. The study followed a large sample of over 10,000 children from school entry through the infant stage, i.e. children aged 4-7 years. It used multilevel statistical procedures to model effects of class size differences while controlling for sources of variation that might affect the relationship with academic achievement, and a multimethod research approach, integrating teachers' judgements and experiences with case studies, and also carefully designed time allocation estimates and systematic observation data. Results showed that there was a clear effect of class size differences on children's academic attainment over the (first) Reception year. In the case of literacy, the lowest attainers on entry to school benefited most from small classes, particularly below 25. Connections between class size and classroom processes were examined and a summary model of relationships presented. Effects were multiple, not singular; in largeclasses there are more large groups and this presented teachers with more difficulties, in smaller classes there was more individual teacher contact with pupils and more support for learning, and in larger classes there was more pupil inattentiveness and off-task behaviour. Results support a contextual approach to classroom learning, within which class size differences have effects on both teachers and pupils. It is concluded that much will depend on how teachers adapt their teaching to different class sizes and that more could be done in teacher training and professional development to address contextual features like size of class