Effects of timing of formative feedback in computer-assisted learning environments

This study examines the effects of timing of corrective formative feedback on processing text information on question-answering. Undergraduate students read an expository text and answered questions in two attempts. Students were randomly assigned to a no feedback, immediate feedback and delayed feedback conditions. Students in the feedback conditions received feedback on the correctness of their answer after the first attempt and were informed about the right answer after the second attempt. Students were prompted to restudy the text after failing in their first attempt. However, students in the no feedback condition were just prompted to search the text. All students were tested on question-answering, corrective probability and a post-test cued-recall test. Results showed that: (a) feedback reduced the initial time reading the text; (b) feedback increased performance on question answering and cued-recall; (c) delayed feedback produced no advantages over immediate feedback. Theoretical and practical implications of these results are discussed.     

The effects of tasks on integrating information from multiple documents.

The authors examine 2 issues: (a) how students integrate information from multiple scientific documents to describe and explain a physical phenomenon that represents a subset of the information in the documents; and (b) the role of 2 sorts of tasks to achieve this type of integration, either writing an essay on a question requiring integration across texts or answering shorter intratext questions that require students to integrate information within a single text, while superficial and deep comprehension measurements are obtained. Undergraduate students answered 1 of the 2 types of questions, and their reading times were recorded. Half of the sample thought aloud. Results showed that the integration question increased integration and decreased the processing of isolated units of information, which enhanced deep learning, whereas no differences between the 2 sorts of tasks on memory recall were apparent. This research also provides evidence for the discrepancy between training and posttraining effects (R. A. Schmidt & R. A. Bjork, 1992). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences for self-regulating task-oriented reading activities.

The goal of this study is to analyze the self-regulation processes present in task-oriented reading activities. In the 1st experiment, we examined the following self-regulation processes in the context of answering questions about an available text: (a) monitoring the comprehension of the question, (b) self-regulating the search process, and (c) monitoring the decision to search. Skilled and less skilled comprehenders from 7th and 8th grades read 2 texts and answered 16 questions while all their actions were recorded on a computer. We hypothesized that skilled comprehenders would differ from less skilled comprehenders on the 1st 2 processes on the basis of their general comprehension skills but that their superiority in the 3rd process would be based on specific characteristics of the interaction between the reader and the text. The results support our hypotheses. In the 2nd experiment, we hypothesized that monitoring the decision to search would be equivalent to judgments of learning (JOLs). Eighth graders made JOLs before answering every question, and then they decided whether to search the text. Our hypothesis was confirmed. Our study reveals that task-oriented reading places specific demands on readers related to metacognitive monitoring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delaying elaborated feedback within computer-based learning environments: The role of summative and question-based feedback

Elaborative feedback (EF) containing explanations on students' responses benefits learning. Computer-based environments provide learners with EF in different ways, for example, on an immediate question-by-question basis or after answering a set of questions. Recent findings also suggest that delaying EF enhances learning. However, it is unclear to what extent different types of delayed-EF favour students' performance. This study examines whether and how two types of delayed-EF (question-based vs. summative) influence students' question-answering performance and final learning over immediate-EF. One hundred thirty-three secondary-school students read a scientific text and answered 12 multiple-choice questions in a computer-based environment. A day later, students completed a final learning test with 20 open-ended questions. Results showed that neither question-based delayed EF nor summative delayed EF outperformed immediate EF. However, EF moderated the relationship between students' prior knowledge and their performance outcomes, suggesting that students with higher levels of prior knowledge receiving summative delayed EF benefited more.     

Two procedures to improve instructional text: Effects on memory and learning.

The goal of this study was to compare 2 approaches for improving instructional text. The first was based on the procedure created by B. K. Britton and S. Gülg?z (1991) as derived from W. Kintsch and T. A. van Dijk's theory (1978). It emphasized the reduction of the reader's inferential activity. We created a second method that was inspired by theories of narrative comprehension (P. van den Broek, 1990; A. C. Graesser, M. Singer, & T. Trabasso, 1994). We oriented it toward triggering causal inferences in the reader. Alternative versions of an original passage on history were elaborated for each of the 2 methods. Sixty-four 8th graders read either the original passage or one of the revised versions and were tested on memory (i.e., recall) and learning (i.e., inference questions). Only the 2nd procedure produced benefits on inferential learning, though both procedures had a limited effect on recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Establishing physico-chemical reference conditions in Mediterranean streams according to the European Water Framework Directive

Type-specific physico-chemical reference conditions are required for the assessment of ecological status in the Water Framework Directive context, similarly to the biological and hydro-morphological elements. This directive emphasises that natural variability of quality elements in high status (reference condition) needs to be quantified. Mediterranean streams often present a marked seasonal pattern in hydrological, biological and geochemical processes which could affect physico-chemical reference conditions. This study establishes general physico-chemical reference conditions (oxygenation, nutrient, salinity and acidification conditions) for different Mediterranean stream types. 116 potential reference sites located in 23 Mediterranean catchments in Spain were sampled in spring, summer and autumn in 2003. All sites were subjected to a screening method for the selection of reference sites in Mediterranean streams (Mediterranean Reference Criteria) and classified using a pre-established stream typology that establishes five different stream types (temporary streams, evaporite-calcareous at medium altitude, siliceous headwaters, calcareous headwaters and large watercourses). Reference conditions (reference value and reference threshold equivalents to high-good class boundary) were calculated using two different methods according to the availability of reference sites: the reference site 75th percentile approach of all reference sites and the 25th percentile of the population approach. The majority of the studied potential reference sites (76 out of 116) were selected as reference sites. Regarding type-specific reference conditions, only siliceous headwaters could be considered different from the rest of stream types because lower conductivity and pH. All reference stream types presented seasonal differences as regards some parameters, except for temporary streams due to the high natural variation of this stream type. For those parameters which presented seasonal differences in a specific stream type, the least restrictive values were proposed as reference conditions.     

Sol–gel preparation of cobalt manganese mixed oxides for their use as electrode materials in lithium cells

An ethanol dehydration procedure has been used to precipitate gel-like citrate precursors containing cobalt and manganese transition metal ions. Further annealing led to the Mn_xCo_3−xO₄ spinel oxide series (x: 1, 1.5, 2, 3). Annealing temperature and treatment time were also evaluated to optimize the performance of the oxides as active electrode materials in lithium cells. The manganese–cobalt mixed oxides obtained by this procedure were cubic or tetragonal phases depending on the cobalt content. SEM images showed spherical macroporous aggregates for MnCo₂O₄ and hollow spheres for manganese oxides. The galvanostatic cycling of lithium cells assembled with these materials demonstrated a simultaneous reduction of cobalt and manganese during the first discharge and separation of cobalt- and manganese-based products on further cycling. As compared with binary manganese oxides, a notorious electrochemical improvement was observed in the mixed oxides. This behavior is a consequence of the synergistic effect of both transition metal elements, associated with the in-situ formation of a nanocomposite electrode material when cobalt is introduced in the manganese oxide composition. Values higher than 400 mAh/g were sustained after 50 cycles for MnCo₂O₄.