Effectiveness of instruction based on the constructivist approach on understanding chemical equilibrium concepts

The purpose of this study was to identify misconceptions concerning chemical equilibrium concepts and to investigate the effectiveness of instruction based on the constructivist approach over traditional instruction on 10th grade students' understanding of chemical equilibrium concepts. The subjects of this study consisted of 71 10th grade students from two chemistry classes of the same teacher. Each teaching strategy was randomly assigned to one class. The data were obtained from 32 students in the experimental group taught with instruction informed by the constructivist approach and 39 students in the control group taught with traditional instruction. The data were analysed using analysis of covariance. The results indicated that the students who used the constructivist principles-oriented instruction earned significantly higher scores than those taught by traditional instruction in terms of achievement related to chemical equilibrium concepts. In addition, students' previous learning and science process skills each made a significant contribution to the achievement related to chemical equilibrium concepts. In light of the findings obtained from the results, an additional misconception of chemical equilibrium concepts was determined in addition to the misconceptions in related literature. This misconception is that when one of the reactants is added to the equilibrium system, the concentration of the substance that was added will decrease below its value at the initial equilibrium.     

Effectiveness of conceptual change instruction on understanding of heat and temperature concepts

This study investigated the differential effects of two modes of instructional program (conceptual change oriented and traditionally designed) and gender difference on students' understanding of heat and temperature concepts, and their attitudes toward science as a school subject. The subjects of this study consisted of 72 seventh grade students from two General Science Classes taking the course from the same teacher. Each teaching method was randomly assigned to one class. The experimental group received reinforcement via the conceptual change texts while the control group utilized traditionally designed science texts over a period of four weeks. Analysis of covariance was used. Logical thinking ability was taken as a covariate. The results showed that the conceptual change oriented instruction produced significantly greater achievement in understanding of heat and temperature concepts. The result for science attitudes as a school subject showed no significant difference between the experimental and control groups. Also, no significant difference was found between the performance of females and that of males in terms of learning heat and temperature concepts and attitudes toward science, but the interaction of treatment regarding to gender was significant for learning the concepts. In addition, it was found that students' logical thinking ability accounted for a significant portion of variation in heat and temperature concepts achievement.     

Students' understanding of molecular structure representations

The purpose of the investigation was to determine the meanings attached by students to the different kinds of molecular structure representations used in chemistry teaching. The students (n = 124) were from primary (aged 13-14 years) and secondary (aged 17-18 years) schools and a university (aged 21-25 years). A computerised 'Chemical Visualisation Test' was developed and applied. The research indicates that students' appreciation of three-dimensional molecular structures differs according to the kind of representation used. The best results were achieved with the use of concrete, and pseudo-concrete types of representations (e.g. three-dimensional models, their photographs, computer-generated models). However, the use of more abstract types (e.g. schematic representations, stereochemical formula) was less effective. A correlation between students' results on the Chemical Visualisation Test and their educational level, spatial visualisation, and spatial relations skills was shown statistically, but no statistically significant gender differences were observed.     

The effects of a history‐based instructional material on the students' understanding of field lines

Many students in physics courses fail to achieve a desired conceptual change because they assign an incorrect ontology to the to‐be‐learned concept. This situation has been detected in previous research for the case of field lines: many college students assign material properties to the lines and describe them, for example, as tubes that contain or transport charges. The historical evolution of this concept shows that early scientists like Faraday assigned material properties to these lines in some occasions. In the present work a history‐based instructional material was designed to foster the analysis of the ontology of field lines to help students at an Argentinean university achieve conceptual change. The predicates used by the students to describe physical situations were used as evidence of the assigned ontological status. Conceptual change was measured by the change in the proportion of geometrical predicates that students used when referring to the lines in a written questionnaire. This change was significantly higher for the students learning with the history‐based material compared to those that learned in the regular class. Some characteristics of the material and geometrical ideas that students hold about the field lines were determined through an oral interview. © 2006 Wiley Periodicals, Inc. J Res Sci Teach     

Quality of geometry instruction and its short-term impact on students' understanding of the Pythagorean Theorem

This article presents findings from a German–Swiss video-based classroom study. The research examines how three basic dimensions of instructional quality impact the development of students' understanding of the Pythagorean Theorem. The study sample comprised 19 German and 19 Swiss mathematics classes. A three-lesson introductory unit on the Pythagorean Theorem was videotaped in all classes. Multilevel analyses revealed both classroom management and cognitive activation to have positive effects on mathematics achievement. The results also provide empirical evidence that cognitive activation and a supportive climate moderate the relationship between mathematics-related interest and mathematics achievement.     

Effect of instruction using students' prior knowledge and conceptual change strategies on science learning

One of the factors affecting students' learning in science is their existing knowledge prior to instruction. The students' prior knowledge provides an indication of the alternative conceptions as well as the scientific conceptions possessed by the students. This study is concerned primarily with students' alternative conceptions and with instructional strategies to effect the learning of scientific conceptions; i.e., to effect conceptual change from alternative to scientific conceptions. The conceptual change model used here suggests conditions under which alternative conceptions can be replaced by or differentiated into scientific conceptions and new conceptions can be integrated with existing conceptions. The instructional strategy and materials were developed for a particular student population, namely, black high school students in South Africa, using their previously identified prior knowledge (conceptions and alternative conceptions) and incorporate the principles for conceptual change. The conceptions involved were mass, volume, and density. An experimental group of students was taught these concepts using the special instructional strategy and materials. A control group was taught the same concepts using a traditional strategy and materials. Pre- and posttests were used to assess the conceptual change that occurred in the experimental and control groups. The results showed a significantly larger improvement in the acquisition of scientific conceptions as a result of the instructional strategy and materials which explicitly dealt with student alternative conceptions.     

Effect of explicit problem solving instruction on high school students' problem-solving performance and conceptual understanding of physics

In this study a two-sample, pre/posttest, quasi-experimental design was used to investigate the effect of explicit problem-solving instruction on high school students' conceptual understanding of physics. Eight physics classes, with a total of 145 students, were randomly assigned to either a treatment or comparison group. The four treatment classes were taught how to use an explicit problem-solving strategy, while the four comparison classes were taught how to use a textbook problem-solving strategy. Students' problem-solving performance and conceptual understanding were assessed both before and after instruction. The results indicated that the explicit strategy improved the quality and completeness of students' physics representations more than the textbook strategy, but there was no difference between the two strategies on match of equations with representations, organization, or mathematical execution. In terms of conceptual understanding, there was no overall difference between the two groups; however, there was a significant interaction between the sex of the students and group. The explicit strategy appeared to benefit female students, while the textbook strategy appeared to benefit male students. The implications of these results for physics instruction are discussed. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 551–570, 1997.     

Undergraduate students' understanding of falling bodies in idealized and real‐world situations

This study investigates the understanding of 18 first‐year undergraduate students when simultaneously presented with two contrasting dynamical situations: the idealized (without air resistance) and real‐world cases of balls being dropped or thrown. Previous work has shown that getting students to recognize flaws in their mental models helps them develop their understanding. Our students were better able to answer correctly the problems in idealized cases than the problems in real‐world cases. For the real‐world cases, the students understood the impact of air resistance on the object's size better than the impact of air resistance on objects of the same size but different mass. In follow‐up interviews, the students reported that using the two different situations in the same test did indeed encourage them to think more carefully. By recognizing the need to include air resistance, they activated their appropriate mental “resources” to deal with the situations. We conclude that using contrasting situations (i.e., with and without an idealization) is a useful teaching tool. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 569–583, 2004     

Contextualizing instruction: Leveraging students' prior knowledge and experiences to foster understanding of middle school science

Contextualizing science instruction involves utilizing students' prior knowledge and everyday experiences as a catalyst for understanding challenging science concepts. This study of two middle school science classrooms examined how students utilized the contextualizing aspects of project‐based instruction and its relationship to their science learning. Observations of focus students' participation during instruction were described in terms of a contextualizing score for their use of the project features to support their learning. Pre/posttests were administered and students' final artifacts were collected and evaluated. The results of these assessments were compared with students' contextualizing scores, demonstrating a strong positive correlation between them. These findings provide evidence to support claims of contextualizing instruction as a means to facilitate student learning, and point toward future consideration of this instructional method in broader research studies and the design of science learning environments. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 79–100, 2008     

Rethinking strategy instruction: direct reading strategy instruction versus computer‐based guided practice

There are many established reading strategy training programmes, which explicitly teach strategic and meta‐cognitive knowledge to improve reading comprehension. Although instruction in strategy knowledge leads to improvements in meta‐cognitive skills, the effects do not always transfer to reading comprehension. Therefore, to investigate preconditions for knowledge transfer, two different strategy training programmes were implemented in nine classes of Grade 6 students (N = 148) over the course of one school year. One programme involved teacher‐directed instruction of declarative meta‐cognitive knowledge (Reading Detectives; Rühl & Souvignier, 2006). The other aimed at improving executive meta‐cognition by guided practice: students worked with a computer program based on latent semantic analysis (LSA) (conText) and received immediate feedback on written summaries. Although both groups improved their strategy knowledge to the same extent, the conText group showed a greater improvement in reading comprehension. These fndings suggest that guided practice, which is characterised by intensive practice and individualised corrective feedback, is superior to explicitly teaching strategy knowledge.     

Exploring identities to deepen understanding of urban high school students' sexual health decision‐making

Sexual health is a controversial science topic that has received little attention in the field of science education, despite its direct relevance to students' lives and communities. Moreover, research from other fields indicates that a great deal remains to be learned about how to make school learning about sexual health influence the real‐life choices of students. In order to provide a more nuanced understanding of young people's decision‐making, this study examines students' talk about sexual health decision‐making through the lens of identities. Qualitative, ethnographic research methods with twenty 12th grade students attending a New York City public school are used to illustrate how students take on multiple identities in relation to sexual health decision‐making. Further, the study illustrates how these identities are formed by various aspects of students' lives, such as school, family, relationships, and religion, and by societal discourses on topics such as gender, individual responsibility, and morality. The study argues that looking at sexual health decision‐making—and at decision‐making about other controversial science topics—as tied to students' identities provides a useful way for teachers and researchers to grasp the complexity of these decisions, as a step toward creating curriculum that influences them. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47:742–762, 2010     

Impact of instruction on learning disabled students' creative thinking

Forty-nine pupils from learning disabilities intermediate-level classrooms served as subjects in the study and were randomly assigned to an experimental and control group. The Torrance Tests of Creative Thinking were used as pretests and posttests. The Purdue Creative Training Program was used to stimulate the learning disabled experimental group's divergent thinking abilities for 14 weeks. Pupils in the learning disabled experimental group made significantly higher scores than did the comparison group on the creativity variables of the verbal subtest of the Torrance Tests of Creative Thinking.     

Within‐year changes in Chinese secondary school students' perceived reading instruction and intrinsic reading motivation

This study aimed to expand on existing research about motivational change by investigating within‐year changes of adolescents' intrinsic reading motivation and perceived reading instruction among students from different grades and achievement levels. Six hundred and ninety five students from 10 secondary schools in Hong Kong voluntarily completed a questionnaire that measured these two variables at the beginning and near the end of a school year. The study's findings indicated that students' intrinsic reading motivation was generally stable over a school year. A significant increase in the perceived degree of mastery goal structure in reading instruction was observed near the end of the school year. Students' perception of instruction remained a strong and positive predictor of intrinsic motivation after controlling their prior motivation and other background variables. Different factors affecting students' motivational change are discussed to provide insights for promoting their reading motivation and counter the prevalent trend of motivational decline.     

Children's understanding of substances,part 1: recognizing chemical change

Arising from a study which explored the development children's concept of a substance (ages 11-14), this two-part paper focuses on the idea of chemical change. Part one considers substance identity and pupils' interaction with the scientific idea of melting and boiling behaviour as a means for identification and the assessment of purity. Evidence is presented which suggests that children do not 'naturally' have a concept of substance identity which allows them to recognize chemical change as a possibility. Instead, their thinking is in terms of the history of samples. The scientific idea of identity led to a confrontation with the idea of chemical change but the pupils were unwilling to accept this phenomenon. The preference was to view the product of a chemical change as a 'mix' of the original substances rather than as a substance in its own right. Implications for teaching are discussed. Part two (in press) goes on to examine the issue of explaining chemical change.     

Children's understanding of substances,Part 2: Explaining chemical change

This is the second part of a paper which focuses on the idea of chemical change (see Johnson 2000). The reported data comes from a study which explored the development of children's concept of a substance (ages 11-14). It examines the use of the ideas of elements, compounds and the bonding between atoms to explain chemical change and the intersection of these ideas with 'basic' particle ideas. Evidence is presented which suggests that the particle ideas were the means by which the pupils came to acknowledge the phenomenon of chemical change, having been unmoved by a macroscopic approach which identified substances by melting and boiling point. Furthermore, a basic particle model in which individual particles still retained the macroscopic properties of the substance was found to inhibit an understanding of chemical change. Findings with respect to a burning candle are reported in a separate section. Important implications for teaching are discussed.     

Promoting understanding of chemical representations: Students' use of a visualization tool in the classroom

Many students have difficulty learning symbolic and molecular representations of chemistry. This study investigated how students developed an understanding of chemical representations with the aid of a computer‐based visualizing tool, eChem, that allowed them to build molecular models and view multiple representations simultaneously. Multiple sources of data were collected with the participation of 71 eleventh graders at a small public high school over a 6‐week period. The results of pre‐ and posttests showed that students' understanding of chemical representations improved substantially (p < .001, effect size = 2.68‐. The analysis of video recordings revealed that several features in eChem helped students construct models and translate representations. Students who were highly engaged in discussions while using eChem made referential linkages between visual and conceptual aspects of representations. This in turn may have deepened their understanding of chemical representations and concepts. The findings also suggest that computerized models can serve as a vehicle for students to generate mental images. Finally, students demonstrated their preferences of certain types of representations and did not use all types of three‐dimensional models interchangeably. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 821–842, 2001