Coordination of aproximations in secondary school students’ understanding of limit concept

The aim of this research is to characterize the coordination of the processes of approximation related to the understanding of the limit of a function. We analyze the answers of 64 post-secondary school students to 7 problems considering the dynamic and metric conception of limit of a function. Results indicate that the metric understanding of the limit in terms of inequality supports that the student is capable of coordinating the approximations in the domain and in the range when lateral approximations coincide. However, the student is not capable of this coordination when lateral approximations do not coincide. This indicates that the metric understanding of the limit begins with the previous construction of the dynamic conception in case of coincidence of the lateral approximations in the range.

¿Existe violencia escolar en Educación Infantil y Primaria? Una propuesta para su evaluación y gestión

La tradición investigadora de la violencia escolar se ha centrado fundamentalmente en los últimos ciclos de Educación Primaria y en la Educación Secundaria Obligatoria, abordándose muy poco la presencia, características, evaluación e intervención de los problemas interpersonales en edades tempranas. El objetivo del presente estudio es la construcción y validación de un cuestionario que identifique el inicio y las formas más frecuentes de violencia escolar en los primeros años de escolarización para diseñar programas de prevención eficaces. Los participantes fueron 195 niños/as del último curso de educación infantil y primer ciclo de educación primaria. La investigación realizada ha mostrado que el instrumento denominado Cuestionario de Evaluación de Violencia Escolar en Infantil y Primaria (CEVEIP) presenta adecuadas propiedades psicométricas. El instrumento consta de 27 ítems en formato de autoinforme que evalúa siete tipologías de violencia que se dan en el contexto escolar en edades tempranas desde tres perspectivas: violencia observada, vivida y realizada. Los resulta-dos ponen de manifiesto que el comportamiento violento está presente desde los primeros años de escolarización, siendo éste de baja o moderada frecuencia e intensidad. Estos niveles de violencia podrían ser aprovechados en el ámbito educativo para una gestión más positiva en el desarrollo personal del alumno/a.

Distortion of self-image: risk factor for obesity in children and teenagers

Introduction: Self-image is important in the behaviour and lifestyle of children and adolescents. Analysing the self-image they have and the factors that might influence their distortion, can be used to prevent problems of obesity and anorexia. The main objective of present publication was to analyse the risk factors that may contribute to self-image distortion. Material and Methods: A descriptive survey study was conducted among 659 children and adolescents in two social classes (low and medium-high), measuring height and weight, calculating BMI percentile for age and gender. Body image and self-perception were registered. Results: The percentage of overweight-obesity is higher in scholars (41.8% boys, 28.7% girls) than in adolescents (30.1% and 22.2% respectively), with no difference between socioeconomic classes. The multinomial logistic regression analysis gives a risk of believing thinner higher (p=0.000) among boys OR=2.9(95%CI:1.43-3.37), school (p=0.000) OR=2.42(95%CI:1.56-3.76) and much lower (p=0.000) between normally nourished OR=0.08(95%CI:0.05-0.13), with no differences according to socioeconomic status. The risk of believing fatter is lower (p=0.000) between boys OR=0.28(95%CI:0.14-0.57), school(p=0.072) OR=0.54(95%CI:0.27-1.6), and much higher among underweight (p=0.000) OR=9x108(95% CI:4x108-19x108). Conclusions: Are risk factors of believing thinner: males, being in a group of schoolchildren and overweight-obesity. Conversely, are risk factors of believing fatter: females, teen and above all, be thin.