A quantitative study of macrobenthos was carried out on three transects on the shelf and continental slope off Chile (22° to 42°S; from 100 to 2000 m water depth) within and beneath the oxygen minimum zone (OMZ). Macrobenthos mean densities ranged from 104 to 13 808 ind m⁻², with highest values off Concepción (∼36°S), where highest chloroplastic pigment equivalents were also measured. Polychaetes were the numerically dominant group in all transects and depths, followed by peracarid crustaceans. Species richness and diversity correlated with observed changes in bottom-water oxygen concentrations and sediment-bound pigments. Our results show that the shelf macrobenthic communities were negatively affected by low oxygen. The non-metric multidimensional scaling (nMDS) analysis evidenced depth-related station groups which may be related to the different environments provided by the water masses involved. Indeed, the depth ranges of stations groups with their specific species inventories coincide quite well with the boundaries of the three important water masses in the region, the Equatorial Subsurface Water (∼50 m to ∼400 m depth), the Antarctic Intermediate Water (∼400 to ∼1200 m depth), and the Pacific Deep Water (>1200 m depth).

This paper describes a research project focused on identifying student-teachers’ critical thinking performance levels in scientific reasoning and, secondly, on analyzing the reliability level of the Critical Thinking Tasks test (CTT). As part of the methodology, a non-probabilistic sample of 129 teacher education students from different majors at Bio-Bio University was considered, and the Critical Thinking Task test was applied to collect data. The data analysis was conducted using descriptive statistics, reliability measures and mean score differences. The data showed that the instrument is reliable (α=0,79); there is also a relatively low performance in the global test and its dimensions; and there are differences between the different teacher education programs. It is concluded that the instrument is reliable, and findings support the idea that knowledge-based areas influence critical thinking. Finally, it is necessary to strengthen specific sub-skills to enhance critical thinking as a contribution for scientific reasoning.

El pensamiento crítico es una competencia relevante hoy en día en la formación universitaria, con escaso consenso conceptual y metodológico en sus instrumentos de medición. En este artículo se ofrece una revisión acerca de los instrumentos que se han utilizado para medir el pensamiento crítico, con la finalidad de generar una discusión que permita una mejor comprensión y valoración de los aspectos que componen esta habilidad. La metodología utilizada consiste en una revisión sistemática de estudios en bases de datos, seleccionando 31 estudios de 97 encontrados, y analizando en profundidad ocho de ellos; se utilizó además, análisis de contenido temático para las definiciones y características de instrumentos. Los resultados señalan la existencia de divergencias a la hora de definir y evaluar el pensamiento crítico, con variedad de instrumentos y escaso consenso en los componentes medidos. Se discute la necesidad de lograr un modelo de Pensamiento Crítico integrado que considere habilidades cognitivas, metacognitivas y disposicionales.

This paper analyzes the concept of critical thinking according to the perspective of a group of preservice teachers from a Chilean university; they are currently in the fourth year of their program. Twenty future teachers participated in a focus group discussion in which they expressed their perspectives on the subject. The answers collected were analyzed using the content analysis technique, which allowed the creation of different categories. Among the most recurrent concepts about critical thinking, we could find: analyzing, reflecting, reasoning, change generation and problem solving. The students defined a critical thinker in their different dimensions: as someone competent, both cognitively and socially, and, at the same time, as someone who takes personal and collective aspects into account. The interviewees also mentioned their role of educating critical thinkers, and explained some of the key elements for making that possible. Some of them were: teaching the importance of feeding on reliable information sources, and accepting feedback from their peers. After a comparison between the interviewees’ conceptualizations and the existing literature, it is found that the students’ perspectives are closely related to those of theory.