Why we should not cut P.E.

Thinking of cutting physical education? Think again. Even as we bemoan children's sedentary lifestyles, we often sacrifice school-based physical education in the name of providing more time for academics. In 2006, only 3.8 percent of elementary schools, 7.9 percent of middle schools, and 2.1 percent of high schools offered students daily physical education or its equivalent for the entire school year (Lee, Burgeson, Fulton, & Spain, 2007). We believe this marked reduction in school-based physical activity risks students' health and can't be justified on educational or ethical grounds. We'll get to the educational grounds in a moment. As to ethical reasons for keeping physical activity part of our young people's school days, consider the fact that childhood obesity is now one of the most serious health issues facing U.S. children (Ogden et al., 2006). School-based physical education programs engage students in regular physical activity and help them acquire skills and habits necessary to pursue an active lifestyle. Such programs are directly relevant to preventing obesity. Yet they are increasingly on the chopping block.

Establishing statistical foundations early : data modeling with young learners

This paper addresses research from a three-year longitudinal study that engaged children in data modeling experiences from the beginning school year through to third year (6-8 years). A data modeling approach to statistical development differs in several ways from what is typically done in early classroom experiences with data. In particular, data modeling immerses children in problems that evolve from their own questions and reasoning, with core statistical foundations established early. These foundations include a focus on posing and refining statistical questions within and across contexts, structuring and representing data, making informal inferences, and developing conceptual, representational, and metarepresentational competence. Examples are presented of how young learners developed and sustained informal inferential reasoning and metarepresentational competence across the study to become “sophisticated statisticians”.

Mandatory naptimes in child care and children's nighttime sleep

Objectives To examine the relationship between mandatory naptimes in child care and children's nighttime sleep duration, both concurrently and 12 months later once in school. Methods A sample of 168 children (50-72 months; 55% males) attending licensed child care centers were observed across their morning and throughout their scheduled naptime. Mandatory naptime was determined as the period in which children were not permitted any alternative activity except lying on their bed. Teachers reported each child's napping in child care. Nighttime and total sleep duration was reported by parents at 2 time points, in child care and in the second semester of their first school year. General linear models were used to examine group differences in sleep duration between children experiencing 0 to 60 minutes and >60 minutes of mandatory naptime, adjusting for key confounders. Path analysis was conducted to test a mediation model in which mandatory naptime is associated with nighttime sleep duration through increased napping in child care. Results Children who experienced >60 minutes of mandatory naptime in child care had significantly less nighttime sleep than those with 0 to 60 minutes of mandatory naptime. This difference persisted at 12-month follow-up, once children were in school. Napping in child care mediated the relationship between mandatory naptime and duration of nighttime sleep. Conclusions Exposure to mandatory naptimes of >60 minutes in child care is associated with decreased duration of nighttime sleep that endures beyond child care attendance. Given the large number of children who attend child care, sleep practices within these settings present an important focus for child health.

Prevalence of refractive errors among schoolchildren in Shiraz, Iran

PURPOSE To determine the prevalence of refractive errors in Shiraz schoolchildren by age and gender. METHODS For this cross-sectional study, random cluster sampling was carried out from students of the 2008-2009 academic year. After the initial interview, ophthalmic examinations including tests of visual acuity, non-cycloplegic and cycloplegic refraction and binocular vision were performed. Myopia was defined as a spherical equivalent < or =-0.50 dioptre (D), hyperopia as > or =+2.0 D, and astigmatism as a cylinder refraction > or =0.75 D. All values for school grade and gender were directly standardized based on the total student population in the 2008-2009 school year. RESULTS A total of 2130 students were sampled, of which 1872 participated in the study (response rate = 87.88%). The prevalence of uncorrected, best-corrected, presenting and spectacle corrected visual acuity of 6/12 or worse in the better eye was 6.46%, 0%, 1.49% and 0.9%, respectively. The prevalence rates of myopia, hyperopia and astigmatism were 4.35% (95% confidence interval [CI]: 2.89-5.82%), 5.04% (95% CI: 3.50-6.58%), and 11.27% (95% CI: 9.81-12.74%), respectively. Anisometropia was detected in 2.58% of schoolchildren. The prevalence of hyperopia significantly decreased with age (P = 0.021). CONCLUSIONS Compared with other reported rates, the prevalence of myopia in the schoolchildren of Shiraz is similar to that in most places excluding East Asian countries, and that of hyperopia is in the mid range.

Lionhearts of the Playworld : An ethnographic case study of the development of agency in play pedagogy

This is an ethnographic case study of the creation and emergence of a playworld – a pedagogical approach aimed at promoting children’s development and learning in early education settings through the use of play and drama. The data was collected in a Finnish experimental mixed-age elementary school classroom in the school year 2003-2004. In the playworld students and teachers explore different social and cultural phenomena through taking on the roles of characters from a story or a piece of literature and acting inside the frames of an improvised plot. The thesis takes under scrutiny the notion of agency in education. It produces theoretically grounded empirical knowledge of the ways in which children struggle to become recognized and agentive actors in early education settings and how their agency develops in their interaction with adults. The study builds on the activity theoretical and sociocultural tradition and develops a methodological framework called video-based narrative interaction analysis for studying student agency as developing over time but manifesting through the situational material and discursive local interactions. The research questions are: 1. What are the children’s ways of enacting their agency in the playworld? 2. How do the children’s agentive actions change and develop over the spring? 3. What are the potentials and challenges of the playworld for promoting student agency? 4. How do the teachers and the children deal with the contradiction between control and agency in the playworld? The study consists of a summary part and four empirical articles which each have a particular viewpoint. Articles I and II deal with individual students’ paths to agency. In Article I the focus is on the role of resistance and questioning in enabling important spaces for agency. Article II takes a critical gender perspective and analyzes how two girls struggled towards recognition in the playworld. It also illuminates the role of imagination in developing a sense of agency. Article III examines how the open-ended and improvisational nature of the playworld interaction provided experiences and a sense of ‘shared agency’ for the students and teachers in the class. Article IV turns the focus on the teachers and analyzes how their role actions in the playworld helped the children to enact agency. It also discusses the challenges that the teachers faced in this work and asks what makes the playworld activity sustainable in the class. The summary part provides a critical literature review on the concept of agency and argues that the inherently contradictory nature of the phenomenon of agency has not been sufficiently theorized. The summary part also locates the playworld intervention in a historical frame by discussing the changing conceptions of adulthood and childhood in the West. By focusing on the changing role of play and art in both adults’ and children’s contemporary lives, the thesis opens up an important but often neglected perspective on the problem of promoting student agency in education. The results illustrate how engaging in a collectively imagined and dramatized pretend play space together with the children enabled the teachers to momentarily put aside their “knower” positions in the classroom. The fictive roles and the narrative plot helped them to create a necessary incompleteness and open-endedness in the activity that stimulated the children’s initiatives. This meant that the children too could momentarily step out of their traditional classroom positions as pupils and initiate action to further the collective play. Engaging in this kind of unconventional activity and taking up and enacting agency was, however, very challenging for the participating children and teachers. It often contradicted the need to sustain control and order in the classroom. The study concludes that play- and drama-based pedagogies offer a unique but undeveloped potential for developing educational spaces that help teachers and children deal with the often contradictory requirements of schooling.

Erityistä tukea tarvitsevien lasten polut esiopetuksesta alkuopetukseen : tukitoimet ja suoriutuminen

The purpose of this follow-up study is to analyse stages of learning and teaching of children with special needs in pre-school and the first two grades of elementary school. The target group included 270 children with special needs. The three year follow-up period for each child began during the pre-school year, and continued until the spring of the second grade in elementary school. Various diagnoses were detected among children in the study group. The disorders were categorised in six classes: the developmentally delayed, children with language development disorder, children with emotional and behavioural disorders, children with attention deficit, children with other non-cognitive disorders and children with extensive developmental disorders. The study's starting point was the situation in pre-school: how the children were placed in pre-school, and what kinds of support they were offered? The purpose of the study was to describe how children with special needs move from different types of groups in pre-school to the different types of classes in the first two grades of elementary school. I also examined how well the children with special needs succeeded in the first two grades of elementary school. An additional purpose was to find out what connections there may be between the paths taken by children with special needs when they move from pre-school to elementary school, the types of support they get, and how they succeed academically in elementary school. The data were gathered mainly by means of questionnaires. In addition the children were studied by means of tests designed to estimate their academic skills at the end of the second grade. In analysing the data I used both quantitative and qualitative methods. Six paths were identified among the children in the study group, based on whether a child was in a group or a class given special teaching or in an ordinary group or class during pre-school and the first two grades of elementary school. In this study, about 53% of the children with special needs moved from pre-school to a regular class in elementary school, and about 47% of the children received special education in elementary school. Among the ordinary groups (n = 69) in pre-school the majority of children (73 %) moved to a regular class in elementary school. Among the children receiving special education (n = 201) in pre-school, 46% moved to a regular class in elementary school. That path turned out to be the one followed by the greatest number of children. Only rarely did children move from an ordinary group in pre-school to a special education class in elementary school. Examination of the results according to the children's transition paths also links together with the viewpoint of integration and segregation. This study indicates that in pre-school special education groups, a significantly greater number of methods supporting children's development were used than in the conventional education groups. The difference was at its greatest inconnection with the use of so-called special rehabilitation methods. A quite wide range of variation was observed in how the children succeeded in elementary school. Success in the tests designed to estimate the children's academic skills was poor for 31% of the children (n = 230) in the first grade study group. For 69 % of the children, however, success in the tests was at least satisfactory. In the second grade study group 34 % of the children (N = 216) got through all the three tests estimating academic skills acceptably. According to this study, a number of children with special needs require special support throughout pre-school and the first two grades of elementary school. The results show that if the children received special support during the pre-school year, a number were able to participate in regular education in elementary school. Keywords: a child with special needs, measures of support, transitions, achievements in school

Noviisiopettajana peruskoulussa : Aloittelevien opettajien autenttisia kokemuksia ensimmäisestä opettajavuodesta

As a Novice Teacher at Comprehensive School: The authentic experiences of the beginning teachers during their first year of teaching The aim of this study is to explicate the novice year of teaching in the light of teachers´ authentic experiences. The subject of this investigation is the teachers´ subjective world of experience during their first academic year of teaching and the sharing of these experiences in collaborative consulting meetings. The themes discussed in the meetings were introduced into the collaborative group by the novice teachers themselves, and the progress of discussion was con-trolled by them. The research data was gathered in a consultative working group where the way a novice teacher starts to interpret, analyze and identify his/her own complex and dynamic teaching situations was observed. The research data gathered in this way illuminates novice teachers´ world of experience and mental picture as well as the unconscious sides of school life. In a theoretical frame of reference, the work of a teacher is identified, according to systemic scientific thought, as a dynamic triangle in which the basic elements are the personality of the teacher, the role of the teacher and the school as an organization. These basic elements form a whole within which the teacher works. The dynamics of this triangle in a teacher’s work are brought to light through the study of the phenomena of groups and group dynamics since a teacher works either as a member of a group (working community), as a leader of a group (teaching situations) or in a network (parent – teacher cooperation). Therefore, tension and force are always present in teaching work. The main research problem was to explain how a novice teacher experiences his/her first working year as a teacher. The participants (n=5) were teaching at five different comprehensive schools in the city of Helsinki. This was their first long-term post as a teacher. The research data consists of seven collaborative consulting meetings, as well as recordings and transcripts of the meetings. A classificatory framework was developed for data analysis which enabled a sys-tematic qualitative content analysis based on theory and material. In addition to the consulting meetings, the teachers were interviewed at the beginning and at the end of the process of collecting the research material. The interviews were used to interpret the meanings of the content analysis based on raw data. The findings show that there is a gap between teacher education and the reality of school life, which causes difficulties for a novice teacher during his/her first teaching year. The gap is rather a global educational problem than a national one, and therefore it is independent of cultural factors. Novice teachers desire a well-structured theory of teacher education and a clear programme where the themes and content delve deeper and deeper into the subject matter during the study years. According to the novice teachers, teacher education frequently consists of sporadic and unconnected study and class situations. An individual content weakness of teacher education is the lack of insufficient initiation into evaluation processes. The novice teachers suggest that a student must be provided good-quality and competent guidance during the study years and during his or her induction. There should be a well-organized, structured and systematic induction program for novice teachers. The induction program should be overseen by an organization so that the requirements of a qualified induction can be met. The findings show that the novice teachers find the first year of teaching at comprehensive school emotionally loaded. The teachers experienced teaching as difficult work and found the workload heavy. Nevertheless, they enjoyed their job because, as they said, there were more pleasant than unpleasant things in their school day. Their main feeling at school was the joy of success in teaching. The novice teachers felt satisfaction with their pupils. The teachers experienced the more serious feelings of anger and disgust when serious violence took place. The most difficult situations arose from teaching pupils who had mental health problems. The toughest thing in the teacher´s work was teaching groups that are too heterogeneous. The most awkward problems in group dynamics happened when new immigrants, who spoke only their own languages, were integrated into the groups in the middle of the school year. Teachers wanted to help children who needed special help with learning but restated at the same time that the groups being taught shouldn’t be too heterogeneous. The teachers wished for help from school assistants so that they could personally concentrate more on teaching. Not all the parents took care of their children according to the comprehensive school law. The teachers found it hard to build a confidential relationship between home and school. In this study, novice teachers found it hard to join the teaching staff at school. Some of the teachers on staff were very strong and impulsive, reacting loudly and emotionally. These teachers provoked disagreement, conflicts, power struggles and competition among the other teachers. Although the novice teachers of the study were all qualified teachers, three of them were not interested in a permanent teaching job. For these teachers teaching at a primary school was just a project, a short period in their working life. They will remain in the teaching profession as long as they are learning new things and enjoying their teaching job. This study is an independent part of the research project on Interplay – Connecting Academic Teacher Education and Work, undertaken by the Department of Applied Sciences of Education at the University of Helsinki. Key words: novice teacher, emotions, groups and group dynamics, authority, co-operation between home and school, teacher community, leadership at school, induction, consulting

"Sitte se menee koulus" : Eri kieli- ja kulttuuritaustaisen lapsen suomen kielen taito esiopetuksen päättövaiheessa

A child learns new things, creates social relationships and participates in play with the help of language. How can a child overcome these challenges if the surrounding language is not his mother tongue? The objective of learning a new language in the Pre-school education is an active bilingualism in all fields of the language. Theoretical context of the research rises from bilingualism, learning a language, language skills and evaluating them. Object of the research was to understand language skills of a child from a different linguistic and cultural background in the final stage of Pre-school education and to clarify how learning Finnish was supported during the Pre-school year. Answers to the research issues will be searched with the following questions: 1) What kind of language skills does a child from a different linguistic and cultural backgrounds have at the final stage of Pre-school education?, 1.1) What kind of listening comprehension skills?, 1.2) What kind of speech and vocabulary skills?, 1.3) What kind of structural skills?, 2) What kind of individual differences are there in language skills of children from different linguistic and cultural backgrounds?, and 3) How has a child from a different linguistic and cultural background been supported in learning Finnish during the Pre-school education? The view of language skills in this research is holistic even though it will be analysed in separate fields. The aim of this research is to form an overall impression of Finnish skills of the children participating in the research. Eight Pre-school-aged children with different linguistic and cultural backgrounds and their kindergarten teachers participated in this research. The children had taken part in Finnish activities for about three years. The research material consists of the test series (KITA), which evaluate children’s language skills – and of the questionnaire to the kindergarten teachers. The purpose of the questionnaire was to provide additional information on children’s language skills in Pre-school teaching situations and on supporting Finnish in Pre-school education. This research is qualitative and processing of the material is based on content analysis. According to the kindergarten teachers, the children’s social language skills were sufficient to cope in everyday life but children needed assistance with longer instructions. The same phenomenon could also be seen with the KITA tests – in which long and abstract instructions turned out to be difficult. Individual differences of the children were perceived in productivity skills, which were realised in fluent or influent speech. The children were supported in learning Finnish individually, in small-groups and in the activities of a whole group. ‘Finnish as the second language’ small-groups were the most common form of support in learning the language. The support at understanding activities was emphasized in whole group situations as well as in individual situations while assisting the child’s language skills. Generally, the children’s language skills were in the same level with developing basic language skills. The data of this research help to understand children’s language skills after three years of adopting Finnish. The results can be utilised in planning and evaluation of teaching another language.

Schoolman family papers, undated, 1889-1994

The Schoolman Papers reflect Dr. Albert P. and Mrs. Bertha Schoolmans' staunch dedication to Jewish education, Jewish causes, and Israel. Bertha Schoolman, a lifelong member of Hadassah, assisted thousands of Israeli youth as chairman of the Youth Aliyah Committee. Her diaries, photos, scrapbooks, and correspondence record her numerous visits to Israel on which she helped set up schools, met with Israeli dignitaries, and participated in Zionist Conferences and events. The collection includes a 1936 letter from Hadassah founder, Henrietta Szold, praising Mrs. Schoolman's work as well as a letter from the father of Anne Frank, thanking Mrs. Schoolman for naming a Youth Aliyah center the "Anne Frank Haven" after his later daughter.

Las habilidades narrativas de niños de 5 años en situación de “hacer que leen un cuento”

Resumen: El presente estudio tuvo por objeto explorar el desarrollo de las habilidades narrativas de niños de 5 años de nivel socioeconómico (NSE) bajo y medio. A principio del año escolar, se les solicitó a los niños que seleccionaran un libro de cuentos y lo “leyeran”. Los niños de NSE bajo no respondieron a la consigna, por lo que se analizó su desempeño narrativo luego de la implementación de una propuesta de alfabetización temprana que incluía la lectura diaria y repetida de cuentos. El análisis de los relatos infantiles permitió identificar diferencias entre los grupos de distinto NSE. Mientras que los niños de NSE medio recuperaban la historia o “hacían que leían” apelando a recursos lingüísticos característicos de historias de ficción, los relatos de los niños de NSE bajo, aún después de la intervención, mantenían marcas de oralidad y estaban ligados a guiones y experiencias personales.

La aventura de investigar. Una experiencia de investigación-acción participativa

[ES]El objetivo de este estudio consiste en desvelar las sensaciones, sentimientos y pensamientos que la aventura de implicarse en una investigación-acción participativa genera sobre los distintos grupos de personas implicadas en una experiencia de Deporte Escolar (DE)(docentes, escolares,coordinadores de DE, familias, monitores, equipos directivos,...). Al comienzo del trabajo se expone el marco teórico en el que se sustenta la investigación, que imbrica la perspectiva metodológica cualitativa y la orientación de pensamiento socio-crítica aplicada en el contexto del DE. A continuación, se describe el diseño de este estudio, que se desarrolló desde el curso escolar 2002/03 hasta el 2006/07, presentando a los participantes, los contextos de acción-formativa construidos, las técnicas de generación de datos utilizadas y, el procedimiento de análisis e interpretación de datos. Después, se pone especial interés en las voces de los participantes para ponerlas en discusión con lo que investigadores del campo han puesto de manifiesto con anterioridad sobre el poder formativo que ejerce la investigación-acción y, finalmente, se recogen las conclusiones principales obtenidas de este estudio.

Análisis cinemático del robot antropomórfico IRB120 de ABB

[ES]En el siguiente Trabajo Fin de Grado se va a exponer el análisis cinemático y desarrollo de un modelo virtual para la implementación de las ecuaciones cinemáticas del robot IRB120 de ABB llevados a cabo durante el curso 2013/2014. Comenzando por un estudio del Estado del Arte de la robótica industrial, se plantean seguidamente las ecuaciones de localización del robot en función de las variables de entrada mediante el método matricial. Estas ecuaciones son implementadas en un modelo de MatLab para usarlas en la resolución del problema de posición directo e inverso, y son también usadas en herramientas de creación de trayectorias. Además, sus derivadas se utilizan en el cálculo de velocidades del elemento terminal. Por último, se muestra la creación del prototipo 3D del robot, así como un interfaz gráfico de control del robot para el usuario, y los trabajos de validación llevados a cabo de los mencionados modelos virtuales sobre el robot real.

An investigation of wind tunnel wall effects at high Mach numbers

This paper presents the results of an investigation of wind tunnel wall interference in a two-dimensional wind tunnel at high Mach numbers. The results are presented in the form of curves of lift coefficient versus the ratio of model chord to tunnel height, as functions of Mach number and angle of attack. The investigation was carried out by the authors at the Guggenheim Aeronautical Laboratory of the California Institute of Technology during the school year 1944-45.

Tests were carried out on the NACA low drag airfoil section 65,1-012 at Mach numbers from .60 to .80, and angles of attack of from 1 to 3 degrees. Models were 1", 2", 4" and 6" chord, giving values of the chord to tunnel height ration of .1 to .6. Schlieren photographs were made of shock waves where they occurred.

O direito de comunicar, por que não? Comunicação alternativa aplicada à pessoas com necessidades educacionais especiais no contexto de sala de aula

Uma criança que não desenvolve a linguagem oral é privada de um dos instrumentos mais fundamentais para atingir o amadurecimento completo como ser humano. O emprego dos recursos da Comunicação Alternativa, envolvendo gestos manuais, expressões faciais e corporais, símbolos gráficos e voz digitalizada ou sintetizada, possibilita a comunicação face a face desta criança. O presente trabalho teve como objetivo geral verificar os efeitos da introdução da Comunicação Alternativa nas interações entre alunos, professores e profissionais de uma escola especial destinada a indivíduos com deficiência mental e deficiência múltipla. A pesquisa, com duração de um ano letivo, composta por três estudos, teve como participantes oito alunos, a professora da turma, que era também a pesquisadora, e uma merendeira. Foram utilizados os sistemas gráficos de Comunicação Alternativa, fundamentados nos procedimentos do ensino naturalístico de Warren e Rogers-Warren. Os três estudos, conduzidos por um delineamento quase experimental de sujeito como seu próprio controle, foram compostos por três fases cada um: linha de base, ensino e follow-up. Todas as sessões foram gravadas em vídeo tape para posterior transcrição. No primeiro estudo, conduzido em 11 sessões experimentais, os alunos foram ensinados a empregar os cartões pictográficos para solicitar permissão para satisfazer necessidades básicas, como ir ao refeitório, ao banheiro, beber água, ouvir música, etc., ou para desempenhar determinadas atividades na sala de aula. No segundo, desenvolvido em 56 sessões experimentais, eles foram ensinados a usar o sistema pictográfico para selecionar os itens de sua refeição, que, anteriormente, eram-lhes oferecidos sem possibilidade de escolha. Neste estudo, a merendeira também foi ensinada a favorecer o uso do sistema pelos alunos. Finalmente, no terceiro estudo, conduzido em 10 sessões experimentais, o sistema pictográfico foi utilizado pelos alunos para favorecer a participação ativa na contagem de histórias pela professora, assim como responder perguntas de compreensão destas histórias. Com efeito, os alunos passaram a fazer uso do sistema de Comunicação Alternativa Ampliada (CAA) para comunicar seus desejos e pensamentos a seus próprios colegas, assim como aos professores, diretores e funcionários da instituição escolar. A possibilidade de se comunicar por meio do sistema pareceu encorajá-los a se expressarem intencionalmente também com vocalizações e verbalizações. A análise dos dados indicou a eficácia do ensino naturalístico para instalação e manutenção do emprego do sistema pictográfico associado a outras modalidades de comunicação a gestual, a vocal e a verbal nas atividades propostas.

Efetividade de um ensaio randomizado de base escolar envolvendo familiares e professores para redução do ganho excessivo de peso em adolescentes

Esta tese é composta por três artigos que veiculam os resultados da realização e análise de uma intervenção de base escolar com o objetivo de reduzir o ganho de peso excessivo em adolescentes. O ensaio, denominado PAPPAS (Pais, Alunos e Professores Pela Alimentação Saudável), foi conduzido com alunos do 5 ano de vinte escolas públicas do município de Duque de Caxias, Rio de Janeiro. As atividades desenvolvidas durante o ano letivo de 2010 desencorajaram o consumo de bebidas adoçadas e biscoitos e estimularam o consumo de feijão e frutas. Pais/ responsáveis e professores receberam informação e material de divulgação sobre os mesmos temas abordados em sala de aula. O consumo de alimentos foi avaliado por meio de um questionário de frequência alimentar aplicado ao início e ao final do estudo. A aferição do peso e da estatura se deu em três momentos: na linha de base, na metade do ano letivo e ao fim do estudo. Para as análises longitudinais, empregou-se modelos generalizados lineares mistos, que levam em conta tanto os dados faltantes quanto o efeito de conglomerado. No primeiro artigo é apresentado o efeito da intervenção no Índice de Massa Corporal (IMC) dos estudantes. Análise por intenção de tratamento revelou que a alteração no IMC dos adolescentes ao longo do tempo não foi estatisticamente diferente entre os grupos intervenção e controle. Observou-se redução estatisticamente significativa no consumo de bebidas adoçadas e biscoitos e aumento no consumo de frutas nos participantes do grupo intervenção quando comparados aos do grupo controle. Pôde-se concluir que estratégias baseadas exclusivamente na qualidade da dieta podem não levar à alterações no peso corporal de adolescentes. No segundo artigo verificou-se a influência do estágio de prontidão para modificação dos hábitos alimentares dos adolescentes na alteração do consumo de refrigerantes, biscoitos e frutas. Observou-se maior alteração no consumo dentre os participantes do grupo intervenção que se encontravam nos estágios de ação na linha de base (relataram já ter alterado seus hábitos alimentares), sugerindo que essa estratégia pode auxiliar em estudos de intervenção visando à alteração do comportamento. O terceiro artigo revisou evidências do ajuste inadequado para características da linha de base, em análises de ensaios randomizados de base escolar que objetivaram alteração no estado nutricional de adolescentes. Foram avaliados 37 estudos e 35% apresentaram desbalanceamento estatisticamente significativo para o IMC na linha de base. Concluiu-se que o ajuste para o IMC na linha de base é frequente em ensaios comunitários randomizados, porém, esta prática força um balanço, que pode levar à resultados espúrios sobre o efeito do tratamento. Os resultados dos artigos 2 e 3 permitem explicar, ao menos em parte, as inconsistências nos resultados de estudos de intervenções voltadas para alteração de hábitos alimentares em escolares.