Effects of text structures on interest and memory in expository texts

Abstract: The purpose of the study was to examine the effects of expository-text structures on interest and memory. Three methods of structuring texts used in the study were detailing, contextualizing, and questioning strategies. Students in grades 6 and 7 participated in the study. Two experiments were conducted. In the experiment 1, a within-subject design was used to investigate differences in text interests among different forms of texts. In the experiment 2, a between-subject design was used to investigate the effects of the textstructuring strategies on text comprehension and memory as well as text interest. Results of the experiment 1 showed that students selected contextualized texts as the most interesting. The reason was that students felt contextualized texts practically relevant to their real lives. In addition, texts constructed by using the strategies showed significantly higher levels of interest than the base text where no strategies were applied. However, in the experiment 2, no significant differences in text interest were found among the different forms of texts. In addition, scores on the text comprehension and memory tests were significantly higher in the base and questioning-strategy texts than in the other two forms of texts. Especially, the lowest performance was found in the contextualized texts. The results of the study provide practical implications on how to structure expository texts commonly used in school to enhance motivation and learning outcomes. Specifically, the results suggested that it would be the most desirable to construct text contents so as to create cognitive conflicts to readers, when text interest, comprehension, and memory are all considered

Locating Acoustic Events Based on Large-Scale Sensor Networks

Research on acoustic source localization is actively being conducted to enhance accuracy and coverage. However, the performance is inherently limited due to the use of expensive sensor nodes and inefficient communication methods. This paper proposes an acoustic source localization algorithm for a large area that uses low-cost sensor nodes. The proposed mechanism efficiently handles multiple acoustic sources by removing false-positive errors that arise from the different propagation ranges of radio and sound. Extensive outdoor experiments with real hardware validated that the proposed mechanism could localize four acoustic sources within a 3 m error in a 60 m by 60 m area, where conventional systems could hardly achieve similar performance