The effects of preschool and school interventions typically fade out over time. To assess the implications of such fade-out for returns to interventions and for skill development theories, it is essential to know the mechanisms underlying fade-out. In this study, we reviewed and catego-rized potential fade-out mechanisms and developed testable hypotheses about the distribution of intervention effect sizes. We then evaluated the hypotheses using meta-analysis and data from 42 studies and 677 effect sizes examining the effects of school interventions targeting at-risk students on standardized tests in mathematics and reading. Our findings show that mecha-nisms linked to challenges of measuring and estimating effect sizes explain only a small part of fade-out. Fade-out appears to be a genuine phenomenon reflecting real changes in the skills of the intervention participants. Among skill-based mechanisms, we found evidence against the treatment group forgetting the skills they acquired in the intervention. We found the most sup-port for mechanisms predicting that the treatment group’s skills would grow, but more slowly than those of the control group after the intervention. The two most plausible mechanisms ex-plain the slower growth by the treatment group’s inability to build on the skills acquired during the intervention, and by negative side effects on parental and school investments for the treat-ment group. Because these mechanisms have different implications for the returns to interven-tions and for theories of skill development, future research should aim to distinguish their con-tributions to fade-out. We conclude by discussing study designs that can achieve this goal.

AbstractBackgroundAnxiety and stress responses are often considered normative experiences, and children and adolescents may benefit from anxiety prevention programmes. One such programme is FRIENDS which is based on a firm theoretical model which addresses cognitive, physiological and behavioural processes. FRIENDS is manualised and can, thus, easily be integrated into school curriculums.ObjectivesWhat are the effects of the FRIENDS preventive programme on anxiety symptoms in children and adolescents? Do the effects differ between participant age groups, participant socio‐economic status, type of prevention, type of provider, country of implementation and/or implementation issues in relation to the booster sessions and parent sessions?Search MethodsThe database searches were carried out in September 2023, and other sources were searched in October 2023. We searched to identify both published and unpublished literature. A date restriction from 1998 and onwards was applied.Selection CriteriaThe intervention was three age‐appropriate preventive anxiety programmes: Fun FRIENDS, FRIENDS for Life, and My FRIENDS Youth. Primary outcome was anxiety symptoms and secondary outcome was self‐esteem. Studies that used a control group were eligible, whereas qualitative approaches were not.Data Collection and AnalysisThe number of potentially relevant studies was 2865. Forty‐two studies met the inclusion criteria. Twenty‐eight studies were used in the data synthesis. Four studies had a critical risk of bias. Six studies did not report data that enabled calculation of effect sizes and standard errors. Two studies had partial overlap of data to other studies used, and two were written in Persian. Meta‐analyses were conducted on each outcome separately. All analyses were inverse variance weighted using random effects statistical models.Main ResultsStudies came from 15 different countries. Intervention start varied from 2001 to 2016. The average number of participants analysed was 240, and the average number of controls was 212. Twenty‐five comparisons reported on anxiety symptoms post‐intervention. The weighted average standardised mean difference (SMD) was 0.13 (95% CI 0.04 to 0.22). There was some heterogeneity. Twelve comparisons reported on anxiety symptoms at 12 months follow‐up. The weighted average SMD was 0.31 (95% CI 0.13 to 0.49). There was a large amount of heterogeneity. Five comparisons reported on self‐esteem post‐intervention with a weighted average SMD of 0.20 (95% CI −0.20 to 0.61) and a large amount of heterogeneity. At follow‐up, we found evidence that programmes implemented by mental health providers appears to perform better than programmes implemented by teachers. The evidence was inconclusive beyond 12 months follow‐up.Authors' ConclusionsOur results indicate that the FRIENDS intervention may reduce anxiety symptoms in children and adolescents when reported by children and adolescents themselves. The majority of trials employed a wait‐list design, implying only a few studies reported on the long‐term effects of the FRIENDS intervention. Our findings suggest that the FRIENDS intervention may increase the reduction in anxiety symptoms 12 months after the intervention. This emphasises the need for future research that apply designs that allows for long‐term follow‐up. We are uncertain about the effects on self‐esteem. The overall certainty of evidence varied from low to very low. There is a need for more rigorously conducted studies.

Healthy after-school activities such as participation in organised sport have been shown to serve as important resources for reducing school failure and other problem/high-risk behaviour. It remains to be established to what extent organised sport participation has positive impacts on young people in unstable life circumstances. What are the effects of organised sport on risk behaviour, personal, emotional and social skills of young people, who either have experienced or are at-risk of experiencing an adverse outcome? The database searches were carried out in March 2023 and other sources were searched in May 2023. We searched to identify both published and unpublished literature. The intervention was participation in leisure time organised sport. Young people between 6 and 18 years of age, who either have experienced or are at-risk of experiencing an adverse outcome were eligible. Primary outcomes were problem/high-risk behaviour and a secondary outcomes social and emotional outcomes. Studies that used a control group were eligible for. Studies that utilised qualitative approaches were not. The number of potentially relevant studies was 43,716. Thirteen studies met the inclusion criteria. Only seven studies could be used in the data synthesis. Five studies were judged to have a critical risk of bias and were excluded from the meta-analysis. One study did not report data that enabled the calculation of effect sizes and standard errors. Meta-analyses were conducted on each conceptual outcome separately. All analyses were inverse variance weighted using random effects statistical models. Two studies were from Canada, one from Australia, and the remaining from the USA. The timespan of the interventions was 23 years, from 1995 to 2018. The median number of participants analysed was 316, and the median number of controls was 452. A number of primary outcomes were reported but each in a single study only. Concerning secondary outcomes, two studies reported the effect on overall psychosocial adjustment at post-intervention. The standardised mean difference was 0.70 (95% CI 0.28–1.11). There was a small amount of heterogeneity. Three studies reported on depressive symptoms at 0–3 years follow-up. The standardised mean difference was 0.02 (95% CI −0.01 to 0.06). There was no heterogeneity between the three studies. In addition, a number of other secondary outcomes were reported each in a single study only. There were too few studies included in the meta-analyses in order for us to draw any conclusion. The dominance of Northern America clearly limiting the generalisability of the findings. The majority of the studies were not considered to be of overall high quality and the process of excluding studies with critical risk of bias from the meta-analysis applied in this review left us with only 7 of a total of 13 possible studies to synthesise. Further, because too few studies reported results on the same type of outcome, at most three studies could be combined in a particular meta-analysis and no meta-analysis could be performed on any of the primary outcomes.

Objectives This is the protocol for a Campbell systematic review. The objectives are as follows: The first objective is to find and describe machine and statistical learning (ML) methods designed for moderator meta-analysis. The second objective is to find and describe applications of such ML methods in moderator meta-analyses of health, medical, and social science interventions. These two parts of the meta-review will primarily involve a systematic review and will be conducted according to guidelines specified by the Campbell Collaboration (MECCIR guidelines). The outcomes will be a list of ML methods that are designed for moderator meta-analysis (first objective), and a description of how (some of) these methods have been applied in the health, medical, and social sciences (second objective). The third objective is to examine how the ML methods identified in the meta-review can help researchers formulate new hypotheses or select among existing ones, and compare the identified methods to one another and to regular meta-regression methods for moderator analysis. To compare the performance of different moderator meta-analysis methods, we will apply the methods to data on tutoring interventions from two systematic reviews of interventions to improve academic achievement for students with or at risk-of academic difficulties, and to an independent test sample of tutoring studies published after the search period in the two reviews.

This is the protocol for a Campbell systematic review. The objectives are as follows: What are the effects of proactive resilience programmes offered to employees in high-risk occupations on resilience and psychological adaptation?

Objectives: This review assesses the evidence about the effects of detention on the mental and physical health and social functioning of asylum seekers. Method and Analysis: We followed Campbell Collaboration guidelines to conduct a systematic review. Meta-analytic methods were used to quantitatively synthesize the study results. Results: Primary study effect sizes for post-traumatic stress disorder, depression, and anxiety, while the asylum seekers were still detained lies in the range 0.35–0.99, all favoring the nondetained asylum group. Author’s Conclusions: There is some evidence to suggest an independent adverse effect of detention on the mental health of asylum seekers. The conclusions should however be interpreted with caution as they are based on few studies. More research is needed in order to fully investigate the effect of detention on mental health.

This is the protocol for a Campbell systematic review. The main objective of this review is to answer the research question: What are the effects of organised sport on risk behaviour, personal, emotional and social skills of young people, who either have experienced or is at-risk of experiencing an adverse outcome? Further, the review will attempt to answer if the effects differ between participants characteristics such as gender, age and risk indicator or between types of sport (e.g., team/individual, contact/non-contact, intensity and duration).

Abstract Background Class size reductions in general education are some of the most researched educational interventions in social science, yet researchers have not reached any final conclusions regarding their effects. While research on the relationship between general education class size and student achievement is plentiful, research on class size in special education is scarce, even though class size issues must be considered particularly important to students with special educational needs. These students compose a highly diverse group in terms of diagnoses, functional levels, and support needs, but they share a common need for special educational accommodations, which often entails additional instructional support in smaller units than what is normally provided in general education. At this point, there is however a lack of clarity as to the effects of special education class sizes on student academic achievement and socioemotional development. Inevitably, such lack of clarity is an obstacle for special educators and policymakers trying to make informed decisions. This highlights the policy relevance of the current systematic review, in which we sought to examine the effects of small class sizes in special education on the academic achievement, socioemotional development, and well‐being of children with special educational needs. Objectives The objective of this systematic review was to uncover and synthesise data from studies to assess the impact of small class sizes on the academic achievement, socioemotional development, and well‐being of students with special educational needs. We also aimed to investigate the extent to which the effects differed among subgroups of students. Finally, we planned to perform a qualitative exploration of the experiences of children, teachers, and parents with class size issues in special education. Search Methods Relevant studies were identified through electronic searches in bibliographic databases, searches in grey literature resources, searches using Internet search engines, hand‐searches of specific targeted journals, and citation‐tracking. The following bibliographic databases were searched in April 2021: ERIC (EBSCO‐host), Academic Search Premier (EBSCO‐host), EconLit (EBSCO‐host), APA PsycINFO (EBSCO‐host), SocINDEX (EBSCO‐host), International Bibliography of the Social Sciences (ProQuest), Sociological Abstracts (ProQuest), and Web of Science (Clarivate, Science Citation Index Expanded & Social Sciences Citation Index). EBSCO OPEN Dissertations was also searched in April 2021, while the remaining searches for grey literature, hand‐searches in key journals, and citation‐tracking took place between January and May 2022. Selection Criteria The intervention in this review was a small special education class size. Eligible quantitative study designs were studies that used a well‐defined control or comparison group, that is, studies where there was a comparison between students in smaller classes and students in larger classes. Children with special educational needs in grades K‐12 (or the equivalent in European countries) in special education were eligible. In addition to exploring the effects of small class sizes in special education from a quantitative perspective, we aimed to gain insight into the lived experiences of children, teachers, and parents with class size issues in special education contexts, as they are presented in the qualitative research literature. The review therefore also included all types of empirical qualitative studies that collected primary data and provided descriptions of main methodological issues such as selection of informants, data collection procedures, and type of data analysis. Eligible qualitative study designs included but were not limited to studies using ethnographic observation or field work formats, or qualitative interview techniques applied to individual or focus group conversations. Data Collection and Analysis The literature search yielded a total of 26,141 records which were screened for eligibility based on title and abstract. From these, 262 potentially relevant records were retrieved and screened in full text, resulting in seven studies being included: three quantitative and five qualitative studies (one study contained both eligible quantitative and qualitative data). Two of the quantitative studies could not be used in the data synthesis as they were judged to have a critical risk of bias and, in accordance with the protocol, were excluded from the meta‐analysis on the basis that they would be more likely to mislead than inform. The third quantitative study did not provide enough information enabling us to calculate an effect size and standard error. Meta‐analysis was therefore not possible. Following quality appraisal of the qualitative studies, three qualitative studies were judged to be of sufficient methodological quality. It was not possible to perform a qualitative thematic synthesis since in two of these studies, findings particular to special education class size were scarce. Therefore, only descriptive data extraction could be performed. Main Results Despite the comprehensive searches, the present review only included seven studies published between 1926 and 2020. Two studies were purely quantitative (Forness, 1985; Metzner, 1926) and from the U.S. Four studies used qualitative methodology (Gottlieb, 1997; Huang, 2020; Keith, 1993; Prunty, 2012) and were from the US (2), China (1), and Ireland (1). One study, MAGI Educational Services (1995), contained both eligible quantitative and qualitative data and was from the U.S. Authors' Conclusions The major finding of the present review was that there were virtually no contemporary quantitative studies exploring the effects of small class sizes in special education, thus making it impossible to perform a meta‐analysis. More research is therefore thoroughly needed. Findings from the summary of included qualitative studies reflected that to the special education students and staff members participating in these studies, smaller class sizes were the preferred option because they allowed for more individualised instruction time and increased teacher attention to students' diverse needs. It should be noted that these studies were few in number and took place in very diverse contexts and across a large time span. There is a need for more qualitative research into the views and experiences of teachers, parents, and school administrators with special education class sizes in different local contexts and across various provision models. But most importantly, future research should strive to represent the voices of children and young people with special needs since they are the experts when it comes to matters concerning their own lives.

This is the protocol for a Campbell systematic review. The objectives are as follows. The main objective of this review is to answer the following research question: What are the effects of the FRIENDS preventive programme on anxiety symptoms in children and adolescents? Further, the review will attempt to answer if the effects differ between participant age groups, participant socio-economic status, type of prevention (universal, selective or indicated), type of provider (lay or mental health provider), country of implementation (Australia or other countries) and implementation issues in relation to the booster sessions and parent sessions (implemented, partly implemented or not at all).

This is the protocol for a Campbell systematic review. The objectives are as follows: provide an overview of the existing evidence base by identifying available systematic reviews and primary effectiveness studies, identify clusters of evidence suitable for a systematic review and identify gaps in evidence where primary research is needed.

Abstract Background Adopted children and children placed in foster care are at increased risk of developing a range of mental health, behavioural, and psychosocial adjustment problems. Previous studies suggest that due to early experiences of separation and loss some children may have difficulties forming a secure attachment relationship with the adoptive/foster parents. Objectives The objectives of the present review were: (1) to assess the efficacy of attachment‐based interventions on measures of favourable parent/child outcomes (attachment security, dyadic interaction, parent/child psychosocial adjustment, behavioural and mental health problems, and placement breakdown) within foster and adoptive families with children aged between 0 and 17 years. (2) to identify factors that appear to be associated with more effective outcomes and factors that modify intervention effectiveness (e.g., age of the child at placement and at intervention start, programme duration, programme focus). Search Methods Relevant studies were identified through electronic searches of bibliographic databases, governmental and grey literature repositories, hand search in specific targeted journals, citation tracking, contact to international experts and Internet search engines. The database searches were carried out to October 2020. Selection Criteria The interventions of interest were parenting interventions aimed at helping the foster/adopted children and their parents to form or sustain a secure attachment relationship. The interventions had to be at least partly informed by attachment theory. Data Collection and Analysis The total number of potentially relevant studies constituted 17.822 hits after duplicates were removed. A total of 44 studies (27 different populations) met the inclusion criteria and were critically appraised by the review authors. Due to critical study quality, missing numeric data and re‐use of the same data, only 24 studies analysing 16 different populations could be used in the data synthesis (children, N = 1302; parents, N = 1344). Meta‐analysis using both child and parent outcomes were conducted on each metric separately. All analyses were inverse variance weighted using random effects statistical models. Random effects weighted mean effect sizes were calculated using 95% confidence intervals (CIs). When possible, we conducted moderator analysis using meta‐regression and single factor sub group moderator analysis. Sensitivity analysis were conducted across study design and domains of the risk of bias assessment. Main Results Ten studies analysed the effect of attachment‐based interventions on the overall psychosocial adjustment of foster or adopted children as reported by their caregivers post intervention. Measures used include the Child Behaviour Checklist, The Strengths and Difficulties Questionnaire, Brief Infant–Toddler Social and Emotional Assessment (BITSEA) and Eyberg Child Behaviour Inventory. The random effects weighted standardised mean difference (SMD) favouring the intervention group was 0.37 (95% CI, 0.10–0.65) and statistically significant. Three studies analysed the effects of attachment‐based interventions on the observed attachment security of foster and adopted children as measured by independent observation. Measures include the Strange Situation Procedure, Attachment Q‐Set, and The Emotional Availability Clinical Screener. The random effects weighted SMD was 0.59 (95% CI, −0.40–1.57) and not statistically significant. Four studies analysed the effect of attachment‐based interventions on positive child behaviour post intervention as measured by independent observation of video‐taped interaction between the child and caregivers. Measures include Disruptive Behaviour Diagnostic Observation Schedule (DB‐DOS) and Emotional Availability Scales). The random effects weighted SMD was 0.39 (95% CI, 0.14–0.64) and statistically significant. Ten studies analysed the effect of attachment‐based interventions on positive parenting behaviour post intervention as measured by independent observation of video‐taped interaction between the child and caregivers or coding of audio‐taped recordings of parental speech. Measures include Adapted Ainsworth Scales for sensitivity and noninterference, Measurement of Empathy in Adult–Child Interaction, The Dyadic Parent–Child Interaction Coding System, Reflective functioning scale, and Emotional Availability Scales. The random effects weighted SMD was 1.56 (95% CI, 0.81–2.31) and statistically significant. Nine studies analysed the effect of attachment‐based interventions on self‐reported post intervention parenting stress (Parenting Stress Index). The random effects weighted SMD was 0.24 (95% CI, 0.03–0.46.) and statistically significant. Three studies analysed the effect of attachment‐based interventions on parental post intervention self‐reported depressive symptoms (Beck Depression Inventory). The random effects weighted SMD was 0.59 (95% CI, −0.08–1.25.) and not statistically significant. Follow‐up analyses were carried out for the outcomes externalising behaviour, positive parenting, and parenting stress, but due to the low number of studies, results should be viewed with caution. Results of the single factor sub group moderator analysis suggest that it cannot be ruled out the effects differ depending on whether the interventions take place in the family home or in a clinical setting. However, it is unclear which location is associated with more positive effects as our findings differ between child and parent outcomes. Results of the sensitivity analysis showed no appreciable changes in the results following the removal of any of the studies in any of the analyses. Authors' Conclusions Parenting interventions based on attachment theory increase positive parent/child interactional behaviours, decrease parenting stress, and increase the overall psychosocial adjustment of children in foster and adoptive families postintervention. Due to the low number of studies evidence regarding the effects of attachment‐based parenting interventions on attachment security and disorganised attachment in foster and adopted children was inconclusive. Theoretically, it is possible that child attachment security and/or attachment disorganisation cannot change within the relatively short period of time that parenting interventions typically last. It is possible that if postintervention improvements in parenting behaviours are sustained over time, it may lead to possible improvement in child attachment security and a decrease in child disorganised attachment. Thus, more longitudinal research is needed. Furthermore, evidence regarding the long‐term effects of attachment‐based parenting interventions on any outcomes was inconclusive due to too few studies, but findings suggest that attachment‐based interventions increase positive parenting behaviour at follow‐up points 3–6 months after the intervention. No study included in the present review provided a measure of placement stability or breakdown as an outcome, which could be used in the meta‐analysis. This further emphasises the need for future longitudinal research in prevention of placement breakdown.

Abstract Background Low levels of numeracy and literacy skills are associated with a range of negative outcomes later in life, such as reduced earnings and health. Obtaining information about effective interventions for children with or at risk of academic difficulties is therefore important. Objectives The main objective was to assess the effectiveness of interventions targeting students with or at risk of academic difficulties in kindergarten to Grade 6. Search Methods We searched electronic databases from 1980 to July 2018. We searched multiple international electronic databases (in total 15), seven national repositories, and performed a search of the grey literature using governmental sites, academic clearinghouses and repositories for reports and working papers, and trial registries (10 sources). We hand searched recent volumes of six journals and contacted international experts. Lastly, we used included studies and 23 previously published reviews for citation tracking. Selection Criteria Studies had to meet the following criteria to be included: Population: The population eligible for the review included students attending regular schools in kindergarten to Grade 6, who were having academic difficulties, or were at risk of such difficulties. Intervention: We included interventions that sought to improve academic skills, were conducted in schools during the regular school year, and were targeted (selected or indicated). Comparison: Included studies used an intervention‐control group design or a comparison group design. We included randomised controlled trials (RCT); quasi‐randomised controlled trials (QRCT); and quasi‐experimental studies (QES). Outcomes: Included studies used standardised tests in reading or mathematics. Setting: Studies carried out in regular schools in an OECD country were included. Data Collection and Analysis Descriptive and numerical characteristics of included studies were coded by members of the review team. A review author independently checked coding. We used an extended version of the Cochrane Risk of Bias tool to assess risk of bias. We used random‐effects meta‐analysis and robust‐variance estimation procedures to synthesise effect sizes. We conducted separate meta‐analyses for tests performed within three months of the end of interventions (short‐term effects) and longer follow‐up periods. For short‐term effects, we performed subgroup and moderator analyses focused on instructional methods and content domains. We assessed sensitivity of the results to effect size measurement, outliers, clustered assignment of treatment, risk of bias, missing moderator information, control group progression, and publication bias. Results We found in total 24,414 potentially relevant records, screened 4247 of them in full text, and included 607 studies that met the inclusion criteria. We included 205 studies of a wide range of intervention types in at least one meta‐analysis (202 intervention‐control studies and 3 comparison designs). The reasons for excluding studies from the analysis were that they had too high risk of bias (257), compared two alternative interventions (104 studies), lacked necessary information (24 studies), or used overlapping samples (17 studies). The total number of student observations in the analysed studies was 226,745. There were 93% RCTs among the 327 interventions we included in the meta‐analysis of intervention‐control contrasts and 86% were from the United States. The target group consisted of, on average, 45% girls, 65% minority students, and 69% low‐income students. The mean Grade was 2.4. Most studies included in the meta‐analysis had a moderate to high risk of bias. The overall average effect sizes (ES) for short‐term and follow‐up outcomes were positive and statistically significant (ES = 0.30, 95% confidence interval [CI] = [0.25, 0.34] and ES = 0.27, 95% CI = [0.17, 0.36]), respectively). The effect sizes correspond to around one third to one half of the achievement gap between fourth Grade students with high and low socioeconomic status in the United States and to a 58% chance that a randomly selected score of an intervention group student is greater than the score of a randomly selected control group student. All measures indicated substantial heterogeneity across short‐term effect sizes. Follow‐up outcomes pertain almost exclusively to studies examining small‐group instruction by adults and effects on reading measures. The follow‐up effect sizes were considerably less heterogeneous than the short‐term effect sizes, although there was still statistically significant heterogeneity. Two instructional methods, peer‐assisted instruction and small‐group instruction by adults, had large and statistically significant average effect sizes that were robust across specifications in the subgroup analysis of short‐term effects (ES around 0.35–0.45). In meta‐regressions that adjusted for methods, content domains, and other study characteristics, they had significantly larger effect sizes than computer‐assisted instruction, coaching of personnel, incentives, and progress monitoring. Peer‐assisted instruction also had significantly larger effect sizes than medium‐group instruction. Besides peer‐assisted instruction and small‐group instruction, no other methods were consistently significant across the analyses that tried to isolate the association between a specific method and effect sizes. However, most analyses showed statistically significant heterogeneity also within categories of instructional methods. We found little evidence that effect sizes were larger in some content domains than others. Fractions had significantly higher associations with effect sizes than all other math domains, but there were only six studies of interventions targeting fractions. We found no evidence of adverse effects in the sense that no method or domain had robustly negative associations with effect sizes. The meta‐regressions revealed few other significant moderators. Interventions in higher Grades tend to have somewhat lower effect sizes, whereas there were no significant differences between QES and RCTs, general tests and tests of subdomains, and math tests and reading tests. Authors’ Conclusions Our results indicate that interventions targeting students with or at risk of academic difficulties from kindergarten to Grade 6 have on average positive and statistically significant short‐term and follow‐up effects on standardised tests in reading and mathematics. Peer‐assisted instruction and small‐group instruction are likely to be effective components of such interventions. We believe the relatively large effect sizes together with the substantial unexplained heterogeneity imply that schools can reduce the achievement gap between students with or at risk of academic difficulties and not‐at‐risk students by implementing targeted interventions, and that more research into the design of effective interventions is needed.

Abstract Background Considering the rapid global movement towards inclusion for students with special educational needs (SEN), there is a surprising lack of pedagogical or didactic theories regarding the ways in which inclusive education may affect students with SEN. Group composition within the educational setting may play a role in determining the academic achievement, socio‐emotional development, and wellbeing of students with SEN. Proponents of inclusion propose that segregated educational placement causes stigmatisation and social isolation which may have detrimental effects on the self‐concept and self‐confidence of students with SEN. On the other hand, opponents of inclusion for all special needs students suggest that placement in general education classrooms may have adverse effects especially if the time and resources allocated for individualisation are not aligned with student needs. Since the 1980s, a number of reviews on the effects of inclusion have been published. Results are inconsistent, and several reviews point to a number of methodological challenges and weaknesses of the study designs within primary studies. In sum, the impact of inclusion on students with SEN may be hypothesised to be both positive and negative, and the current knowledge base is inconsistent. Objectives The objective was first: To uncover and synthesise data from contemporary studies to assess the effects of inclusion on measures of academic achievement, socio‐emotional development, and wellbeing of children with special needs when compared to children with special needs who receive special education in a segregated setting. A secondary objective was to explore how potential moderators (gender, age, type and severity of special need, part or full time inclusive education, and co‐teaching) relate to outcomes. Search Methods Relevant studies were identified through electronic searches in Academic Search Premier (EBSCO), APA PsycINFO (EBSCO), EconLit (EBSCO), ERIC (EBSCO), International Bibliography of the Social Sciences (ProQuest), Sociological Abstracts (ProQuest), Science Citation Index Expanded (Web Of Science), Social Sciences Citation Index (Web Of Science), and SocINDEX (EBSCO). The database searches were completed on 24 April 2021 and other resources: grey literature repositories, hand search in targeted journals and Internet search engines were searched in August/September 2021. The search was limited to studies reported after 2000. Selection Criteria The review included studies of children with special needs in grades K to 12 in the OECD countries. Children with all types of verifiable SEN were eligible. Inclusion refers to an educational setting with a mixture of children with and without SEN. Segregation refers to the separate education of children with SEN. All studies that compared inclusive versus segregated educational settings for children with SEN were eligible. Qualitative studies were not included. Data Collection and Analysis The total number of potentially relevant studies constituted 20,183 hits. A total of 94 studies met the inclusion criteria, all were non‐randomised studies. The 94 studies analysed data from 19 different countries. Only 15 studies could be used in the data synthesis. Seventy‐nine studies could not be used in the data synthesis as they were judged to be of critical risk of bias and, in accordance with the protocol, were excluded from the meta‐analysis on the basis that they would be more likely to mislead than inform. The 15 studies came from nine different countries. Separate meta‐analyses were conducted on conceptually distinct outcomes. All analyses were inverse variance weighted using random effects statistical models. Sensitivity analyses were performed to evaluate the robustness of pooled effect sizes across components of risk of bias. Main Results The average baseline year of the interventions analysed in the 15 studies used for meta‐analysis was 2006, ranging from 1998 to 2012. The average number of participants analysed in the interventions was 151, ranging from 10 to 1357, and the average number of controls was 261, ranging from 5 to 2752. The studies included children with multiple types of disabilities such as learning disorders/intellectual disabilities, autism spectrum disorders, ADHD, physical handicaps, visual impairments, and Down syndrome. At most, the results from eight studies could be pooled in any of the meta‐analyses. All the meta‐analyses showed a weighted average that favoured the intervention group. None of them were statistically significant. The random effects weighted standardised mean difference was 0.20 (95% confidence interval [CI]: −0.01 to 0.42) for overall psychosocial adjustment; 0.04 (95% CI: −0.27 to 0.35) for language and literacy learning outcomes, and 0.05 (95% CI: −0.16 to 0.26) for math learning outcomes. There were no appreciable changes in the results as indicated by the sensitivity analyses. There was some inconsistency in the direction and magnitude of the effect sizes between the primary studies in all analyses and a moderate amount of heterogeneity. We attempted to investigate the heterogeneity by single factor sub‐group analyses, but results were inconclusive. Authors' Conclusions The overall methodological quality of the included studies was low, and no experimental studies in which children were randomly assigned to intervention and control conditions were found. The 15 studies, which could be used in the data synthesis, were all, except for one, judged to be in serious risk of bias. Results of the meta‐analyses do not suggest on average any sizeable positive or negative effects of inclusion on children's academic achievement as measured by language, literacy, and math outcomes or on the overall psychosocial adjustment of children. The average point estimates favoured inclusion, though small and not statistically significant, heterogeneity was present in all analyses, and there was inconsistency in direction and magnitude of the effect sizes. This finding is similar to the results of previous meta‐analyses, which include studies published before 2000, and thus although the number of studies in the current meta‐analyses is limited, it can be concluded that it is very unlikely that inclusion in general increases or decreases learning and psychosocial adjustment in children with special needs. Future research should explore the effects of different kinds of inclusive education for children with different kinds of special needs, to expand the knowledge base on what works for whom.

This is the protocol for a Campbell review. The objective of this systematic review is to uncover and synthesise data from studies to assess the impact of small class sizes on the academic achievement, socioemotional development, and well-being of students with special educational needs. Where possible, we will also investigate the extent to which the effects differ among subgroups of students. Furthermore, we will perform a qualitative exploration of the experiences of children, teachers, and parents with special education class sizes.

Abstract Background School‐based service‐learning is a teaching strategy that explicitly links community service to academic instruction. It is distinctive from traditional voluntarism or community service in that it intentionally connects service activities with curriculum concepts and includes structured time for reflection. Service learning, by connecting education to real world issues and allowing students to address problems they identify, may be particularly efficacious as it increases engagement and motivates students, in particular students who might not respond well to more traditional teaching methods. Objectives The main objective was to answer the following research question: What are the effects of service learning on academic success, neither employed, nor in education or training (NEET) status post compulsory school, personal and social skills, and risk behaviour of students in primary and secondary education (grades kindergarten to 12)? Further, we wanted to investigate study‐level summaries of participant characteristics (e.g., gender, age or socioeconomic level) and quality of the service learning programme. Search Methods We identified relevant studies through electronic searches of bibliographic databases, governmental and grey literature repositories, hand search in specific targeted journals, citation tracking, and Internet search engines. The database searches were carried out in November 2019 and other resources were searched in October 2020. We searched to identify both published and unpublished literature, and reference lists of included studies and relevant reviews were searched. Selection Criteria The intervention was service learning which can be described as a curriculum‐based community service that integrates classroom instruction (such as classroom discussions, presentations, or directed writing) with community service activities. We included children in primary and secondary education (grades kindergarten to 12) in general education. Our primary focus was on measures of academic success and NEET status. A secondary focus was on measures of personal and social skills, and risk behaviour (such as drug and alcohol use, violent behaviour, sexual risk taking). All study designs that used a well‐defined control group were eligible for inclusion. Studies that utilised qualitative approaches were not included. Data Collection and Analysis The total number of potentially relevant studies constituted 13,719 hits. A total of 37 studies met the inclusion criteria. The 37 studies analysed 30 different populations. Only 10 studies (analysing nine different populations) could be used in the data synthesis. Eighteen studies could not be used in the data synthesis as they were judged to have critical risk of bias and, in accordance with the protocol, were excluded from the meta‐analysis on the basis that they would be more likely to mislead than inform. Five studies did not provide enough information enabling us to calculate an effects size and standard error, and one study did not provide enough information to assess risk of bias. Finally, two clusters of studies used the same data sets, resulting in an additional three studies we did not use in the data synthesis. Meta‐analysis of all outcomes were conducted on each conceptual outcome separately. All analyses were inverse variance weighted using random effects statistical models incorporating both the sampling variance and between study variance components into the study level weights. Random effects weighted mean effect sizes were calculated using 95% confidence intervals. We carried out a sensitivity analysis to examine the impact of correcting for clustered assignment of treatments. Main Results The 10 studies (analysing nine different populations) used for meta analysis were all from the United States. The timespan in which included studies were carried out was 33 years, from 1980 to 2013; on average the intervention year was 2007. The average number of participants in the analysed service learning interventions was 937, ranging from 18 to 3556 and the average number of controls was 927, ranging from 20 to 3395. At most, the results from three studies could be pooled in any of the meta‐analyses. All the meta‐analyses showed a weighted average that favoured the intervention group except the pregnancy outcome. None of them was statistically significant except the weighted average of the two studies reporting math test results. The random effects weighted standardised mean difference was 0.09 [95% confidence interval (CI): −0.02 to 0.21] for students' general grade point average; 0.04 (95% CI: −0.08 to 0.16) for reading; 0.21 (95% CI: 0.09 to 0.33) for math; 0.03 (95% CI: −0.10 to 0.16) for days absent from school; 0.13 (95% CI: −0.14 to 0.40) for self‐esteem; 0.07 (95% CI: −0.04 to 0.18) for locus of control. The random effects weighted odds ratio was 1.05 (95% CI: 0.63 to 1.74) for pregnancy and 0.96 (95% CI: 0.74 to 1.25) for sexual risk behaviour. In addition, a number of other outcomes were reported in a single study only. There were no appreciable changes in the results as indicated by the sensitivity analysis. We did not find any adverse effects. Authors' Conclusions In this review, we aimed to find evidence of the effectiveness of service learning on students' academic success, personal and social skills, and risk behaviour. However, the evidence was inconclusive. We found only few randomised controlled trials and the risk of bias in the included non‐randomised studies was very high. All available evidence used in the data synthesis was US‐based. The majority of studies available for meta‐analysis reported on a very limited number of outcomes; in particular few reported results on students' academic success even though the outcome was collected. Further, the majority of studies used in the meta‐analyses reported implementation problems. These considerations point to the need for more rigorously conducted studies performed outside the United States, reporting a larger number of outcomes. It would be natural to consider conducting a series of randomised controlled trial with specific allocation to implementation of high‐quality service learning as guided by the eight standards: (1) Meaningful service, (2) Link to curriculum, (3) Reflection, (4) Diversity, (5) Youth voice, (6) Community partnerships, (7) Progress monitoring and (8) Sufficient duration and intensity. Specific attention would also have to be paid to stringency in terms of conducting a well‐designed randomised trial with low risk of bias and ensuring that the sample sizes are large enough to enable sufficient power.

This is the protocol for a Campbell review. The objectives are as follows: 1.To assess the efficacy of attachment-based interventions on measures of favourable parent/child outcomes (attachment security, dyadic interaction, parent/child psychosocial adjustment, behavioural and mental health problems and placement breakdown) within foster and adoptive families with children aged between 0 and 17 years.2.To identify factors that appear to be associated with more effective outcomes and factors that modify intervention effectiveness (for example, age of the child at placement and at intervention start, programme duration, programme focus).