Una metodología para el estudio de las ideas previas sobre química a través del análisis de expresiones gráficas

Abstract

<p>Se examinaron las respuestas gráficas de hombres y mujeres jóvenes, de 17 años en promedio, inscritos en cursos de nivelación en ciencias. Se encontró que predominan en toda la población alusiones a material de laboratorio y a experimentos. La categoría denominada Iconos/Iconemas (representaciones de sensaciones o sentimientos, o figuras geométricas aisladas) aparece con frecuencia en la población de 17 años. Los análisis muestran que el porcentaje de población que incluye el cuerpo humano en sus expresiones nunca es superior al 30 %. Cuando aparecen figuras humanas sus escenarios dejan ver que son experimentadores, no se muestra el cuerpo humano como parte del estudio químico. Al indagar sobre la orientación vocacional, se encontró que los hombres prefieren carreras científicas y las mujeres optan por programas del área de la salud. El artículo concluye que es posible indagar y analizar la percepción esencial sobre el área de la química gracias al estudio de expresiones gráficas y considerar correspondencias entre edad, sexo y orientación vocacional. Esta información es útil tanto para planear y orientar las actividades de aula, como para inquirir paradigmas y concepciones, y establecer el grado de abstracción y el conocimiento de los estudiantes sobre el alcance y la aplicabilidad de la química.</p>

Gardens as Science Learning Contexts Across Educational Stages: Learning Assessment Based on Students’ Graphic Representations

“…Drawing on graphic expression is a particularly useful strategy in the case of children, since drawing is a meaningful activity ( Scheuer et al, 2002 ) that deeply connects with their personal experience, and allows them to express further significance than just the verbal ( Dai, 2017 ). There exists an extensive corpus of studies that use drawings to detect personal conceptions about scientific topics in students of all ages ( Köse, 2008 ; Margel et al, 2008 ; Anderson et al, 2014 ; Ruìz and Palomeque, 2015 ; Villarroel et al, 2016 ). In addition, there is a theoretical approach based on the construction of knowledge through drawings ( Sanders, 2007 ; Anderson et al, 2014 ; Chang, 2017 ), since graphic representation is considered “an opportunity for the child to construct the science concept” ( Chang, 2017 ), also regarding plant structure and function ( Anderson et al, 2014 ).…”

Reactive Black 5 Removal by Electrochemical Oxidation Using Titanium Dioxide Nanoparticle Electrodes

“…The study revealed the importance of optimizing the following parameters for the electrooxidation degradation of RB5 utilizing nano TiO2: (1) 6 V was the ideal voltage for removing RB5 since it uses comparatively little energy and offers a high apparent rate constant, quick reaction, and 100% removal efficiency in 25 minutes. (2) The effect of electrolyte composition showed that the NaCl solution had a better RB5 removal efficiency than the Na2SO4 solution. Overall, the presence of NaCl in the system positively influences the RB5 removal process by increasing reaction rates, improving adsorption capacity, enhancing mass transfer, and inducing electrochemical effects.…”

“…The obtained measurement served as a baseline for calculating the concentration (using the equation of the standard curve and taking into consideration the dilution factor) and removal efficiency. At regular time intervals (i.e., 0, 2,5,10,15,20,25,30,40,50, and 60 min), 3 mL samples were collected from the electrochemical cell and the absorbance for each sample was evaluated using the UV-Vis spectrophotometer. The RB5 degradation efficiency was evaluated by comparing the absorbance of RB5 concentration at each time interval to the absorbance of its initial concentration (da Silva et al, 2022).…”