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In this study we report on issues related to the use of color as a third dimension on graphical representations provided to students. We find that a majority of the students sampled have a preconceived color map regarding temperature, with blue indicating low temperatures and red indicating high temperatures. Attempts to transfer this particular color map to representations of other quantities, however, may not be successful. In particular, when displaying a topographic map we found that students had a predilection to visualize a hill, regardless of the color map used. Moreover, many students ignored a systematic use of color in favor of seeing a hill in the representation. This suggests that a representation of a feature that seems obvious to an instructor may be interpreted to have a different meaning by a student. Hence, care should be taken to ensure that students interpret the use of color in figures the way the figures are intended.

The state of mathematics and science education in South Africa is a cause for concern. This situation can be attributed, in part, to many mathematics and science teachers' limited content knowledge, ineffective teaching approaches, and unprofessional attitudes. To address these three problem areas simultaneously, a holistic model for the development of Grades 10 to 12 Physical Science teachers was constructed and evaluated against national and international benchmarks. The effects of the model were assessed over a period of four years with 75 teachers. The model was developed in a distance education context, with no face-to-face contact required. It comprises the following elements: a study guide which integrates the development of teachers' content knowledge, pedagogical content knowledge, cognitive skills and experimental skills; reflective journals; assignments; workshops; peer support and science kits. We briefly describe the research that culminated in the Holistic Professional Development (HPD) model, followed by an account of each element of the model. We then present evidence that suggests that the model is effective in helping teachers develop along three desired dimensions, namely, content knowledge, teaching approaches, and professional attitudes.

In this article, we provide three examples of the use of socioscientific issues (SSI) in a 5th-grade classroom. Taken from Earth science (beach sand replacement), life science (the Canadian seal hunt), and physical science (speed limits), the examples show how teachers can embed scientific content in controversial social issues that engage younger students in constructive sociomoral discourse. Each example includes a preliminary learning activity as well as a description of the SSI scenario and its results. The potential of SSI to inspire preservice elementary science methods students to teach more science and create their own modules is also discussed. (Contains 1 table.)

Self-efficacy beliefs play a major role in determining teachers' science teaching practices and have been a topic of great interest in the area of preservice science teacher education. This qualitative study investigated factors that influenced preservice elementary teachers' science teaching self-efficacy beliefs in a physical science content course. The primary data sources included Science Teaching Efficacy Belief Instrument-B (STEBI-B) responses, two semi-structured interviews, classroom observations, and artifacts. Analysis of STEBI-B data was used to select 18 participants with varying levels of self-efficacy beliefs: low, medium, and high. Four categories representing course-related factors contributing towards participants' science teaching self-efficacy beliefs were found: (1) enhanced science conceptual understandings, (2) active learning experiences, (3) teaching strategies, and (4) instructor as a role model. While some course elements such as hands-on learning experiences and inquiry-based teaching strategies seemed to impact all groups positively, the low-group participants were particularly benefited from the ways in which science concepts were presented and the pace at which learning progressed. One implication from this study is that science educators could include elements within science content courses to potentially support preservice teachers with varied initial levels of science teaching self-efficacy.

Many large-lecture introductory science courses for nonscience majors do not have a lab component and hence do not provide much opportunity for students to engage in the practice of science. I have developed a new instructional activity called Dorm Room Labs that enables students to conduct hands-on activities as homework (or dorm room work) to explore more deeply concepts covered in 100-level science courses. The labs focus on concepts relevant to many physical science courses and consist of no-cost or low-cost lab equipment or their smartphones, enabling their use in large-enrollment courses. Using qualitative research methods, I have found that these dorm room experiments have meaningful impact on the development of students' conceptual understanding of several important physics and space science topics. For example giving the students a magnet and compass (or using the student's own smartphone magnetometer) fosters the understanding of the structure of dipole magnetic fields. Dorm Room Labs help engage and motivate students to learn about the process and culture of science by having them "do" science.

Groundwater contamination is a serious environmental problem, given that all living things depend on this essential resource. Groundwater represents less than 1% of all water found on Earth, but nearly 90% of the freshwater used comes from groundwater (USGS 2016). The problem-based activity described in this article actively engages students in real-world issues related to water. Considering water's unique combination of physical and chemical properties, ability to exist in multiple phases, and daily use in agriculture and industry, it is evident that concepts related to water are vital to many scientific domains, including Earth, physical, and life sciences. These activities also can be incorporated into an interdisciplinary unit (e.g., civics class). This lesson lasts approximately one week, including one day for each of the three sections of the lesson, class and independent time for designing students' solutions to a given problem, and at least one class period for presenting and defending the designs.

Background: This investigation was designed to uncover the relations between students' cognitive and metacognitive strategies used during a complex climate simulation. While cognitive strategy use during science inquiry has been studied, the factors related to this strategy use, such as concurrent metacognition, prior knowledge, and prior interest, have not been investigated in a multidimensional fashion. Aims: This study addressed current issues in strategy research by examining not only how metacognitive, surface-level, and deep-level strategies influence performance, but also how these strategies related to each other during a contextually relevant science simulation. Sample: The sample for this study consisted of 70 undergraduates from a mid-sized Southeastern university in the United States. These participants were recruited from both physical and life science (e.g., biology) and education majors to obtain a sample with variance in terms of their prior knowledge, interest, and strategy use. Methods: Participants completed measures of prior knowledge and interest about global climate change. Then, they were asked to engage in an online climate simulator for up to 30 min while thinking aloud. Finally, participants were asked to answer three outcome questions about global climate change. Results: Results indicated a poor fit for the statistical model of the frequency and level of processing predicting performance. However, a statistical model that independently examined the influence of metacognitive monitoring and control of cognitive strategies showed a very strong relation between the metacognitive and cognitive strategies. Finally, smallest space analysis results provided evidence that strategy use may be better captured in a multidimensional fashion, particularly with attention paid towards the combination of strategies employed. Conclusions: Conclusions drawn from the evidence point to the need for more dynamic, multidimensional models of strategic processing that account for the patterns of optimal and non-optimal strategy use. Additionally, analyses that can capture these complex patterns need to be further explored.

The study aimed to determine the most effective of three pedagogies to improve Grade 12 learners' understanding of the photoelectric effect when the teaching was done using chalk and talk, guided learning with computer simulations (CS) as a demonstration tool and semi-autonomous learning where the learners used the CS individually with limited support. A randomised pre-/post-test control group design was implemented. A paired-sample t-test on the post-test scores indicated that the guided learning experimental group (N = 10) performed better than the semi-autonomous learning experimental group (N = 10) [t-statistics, t(9) = -6.135, p < 0.05]. Even the control group (N = 10) where the teacher used chalk and talk performed better than the semi-autonomous learning experimental group. An analysis of covariance on the post-test scores with learners' pre-test scores showed a significant effect on the instructional group favouring the guided learning experimental group. It is, therefore, suggested that guided learning where the teacher manipulates the CS is a better method for the effective teaching of the photoelectric effect.

This paper describes the results of a comparative study into the approaches used by science undergraduates when solving open-ended problems. This study adopted a pseudo-grounded theory framework to analyse six case studies, one from each of the science disciplines studied. The study involved 70 participants from 5 institutions solving open-ended problems using a think-aloud protocol. Analysis of the data identified a number of different approaches used by each subject group. Participants in psychology, pharmacy and sports rehabilitation used a greater number of novice-like approaches than participants in chemistry, physics and interdisciplinary science. The approaches used by physical science participants were very similar whereas those from pharmacy, sports rehabilitation and psychology were more varied and relied on students' ability to relate to a familiar context. Evaluation of the relative quality of solutions showed variation with discipline.

Modeling is a practice of science that is underemphasized in biology classrooms in comparison to its central focus in the physical sciences. Visualizations of the submicroscopic world of molecules are becoming increasingly sophisticated with the evolution of new technologies. With this in mind, we introduced high school biology classrooms to a professional molecular modeling software program used by research biochemists to visualize proteins and other macromolecules. Analysis of surveys completed before and after the use of the program revealed significant student gains in their understandings of the nature of models. Student and teacher perceptions of the program showed an appreciation for the real/authentic nature of the program, and its affordances when utilizing the three-dimensional rendering of proteins. The teachers did report a general level of frustration regarding their lack of experience with the program and their inability to unlock its full potential due to not being able to access all of the program's features. However, we believe that the evidence at hand indicates that the value of introducing students to authentic molecular modeling tools in high school science classrooms outweighs the potential limitations..

Following the calls of international conferences related to the teaching of science and technology, technology education (TE) was integrated as a component of physical sciences programmes in Benin, West Africa. This study investigates physical science teachers' attitudes towards the integration of TE topics in secondary school science curricula in Benin, and the factors influencing the implementation of the programme. It also proposes solutions to overcome issues of implementation. A quantitative research method was used to collect data. A 67-item questionnaire designed by the researchers was distributed to a convenience sample of 176 physical science teachers in the three largest towns in Benin, and the data were statistically analysed using SPSS 19.0. The results showed that teachers were positive about teaching the TE topics. Many issues affected TE integration in the science curriculum including teachers' incapacity to design TE lesson plans; the large class sizes; and most importantly students' inability to understand and speak the instructional language. A variety of solutions were proposed in order to improve the teaching conditions. These included a revision of the TE topics integrated in the programmes, and encouragement of government and school administrators to provide necessary TE teaching materials.

This paper investigates the teaching strategies used by secondary school science teachers in Swazi schools that perform well in national examinations. The performance of learners in science in these examinations is generally low, as indicated by the public examination results published by the Examinations Council of Swaziland. However, a few schools have persistently performed very well over the years. This study sets out to identify the perceptions of teachers in high-performing schools on effective teaching strategies in science and to determine the teachers' actual classroom practices. The study is framed by the classification of effective science teaching strategies developed by Schroeder and colleagues, and by the effective curriculum implementation theory by Rogan and Grayson. The sample comprised all teachers in the 12 schools that performed well during the years 2011-2014 in Junior Secondary School Science, and Senior Secondary School Science Biology and Physical Science. Data were collected through a questionnaire (n = 77) and classroom observations (n = 25). The frequencies with which teachers identified and implemented specific strategies were determined. The results showed that science teachers in high-performing schools were clearly knowledgeable about effective teaching strategies as reported in the literature. However, many of the identified strategies were minimally implemented by the teachers and in most cases, implementation was at a low level of cognitive demand, yet high-performing schools should exemplify the best practices for other schools to emulate. It is suggested that teachers be continually oriented for implementing the demands of any existing curriculum.

Previous research on students' difficulties in learning chemical equilibrium has shown that students hold misconceptions about this topic, and this often results in unintended learning. However, recent developments in human learning from the behavioural sciences perspective indicate that students' difficulties in learning are much more than misconceptions. The purpose of the study was to identify the knowledge and skills that students lack in successfully solving chemical equilibrium problems involving calculation of the equilibrium constant, K[subscript c]. Participants of this study included three students from a high-achieving school and four students from a low-achieving school in the Bohlabela district of Mpumalanga province of South Africa. Data sources included transcripts of students' think-aloud protocols, video recordings of students' problem-solving performance and students' written answers. Results showed that students at the low-achieving school applied personal algorithms exclusively at a superficial level in all phases of the problem-solving process, and committed many errors. Their main difficulty was a lack of conceptual awareness of how a chemical reaction progresses to equilibrium. On the other hand students at the high-achieving school demonstrated conceptual understanding in solving problems in familiar contexts, but lacked the skills for dealing with problems in an unfamiliar context; few errors were observed in their solutions. The results suggest that contextual knowledge is of a higher-order type, and is likely to emerge after students have acquired considerable skills in self-regulation. The implications of the results for teaching of chemical equilibrium are discussed.

School instruction is critical for helping students use energy as a lens for making sense of phenomena, however, students often struggle to see the usefulness of energy analysis for interpreting the world around them. One reason for this may be an over-reliance on the idea of energy forms in introductory energy instruction, which may unintentionally suppress, rather than prompt, insights into how and why phenomena occur. We argue that an approach to energy instruction that emphasizes energy transfers between systems, and does not require the idea of energy forms, provides students with a more consistent and useful set of tools for interpreting phenomena. Such a perspective requires connecting the energy concept to the notion that fields, which mediate interaction-at-a-distance, are a real physical system that can transfer energy -- an idea that is rarely presented in middle school science. We outline an instructional approach in which middle school students learn to interpret phenomena by modelling energy transfers between systems of interacting objects and fields. We argue that this approach presents a more physically accurate picture of energy, helps align energy instruction across disciplines, and supports students in seeing the value of energy as a lens for making sense of phenomena.

The aim of the paper is to explore the knowledge base of high school physical science teachers, from selected high schools in Lesotho, regarding the integration of information and communication technologies (ICTs) into the curriculum. The new physical science curriculum in Lesotho requires the use of ICTs for teaching. The teachers' use of ICTs was explored through a questionnaire based on the technological pedagogical content knowledge model (TPACK). Data were analysed using the statistical analysis software (SAS) and the results showed that 77% of the teachers used ICTs for teaching, while 80% used them for non-teaching activities. The mean score for teachers' TPACK was 2.88. This score is below the average of three for the Likert points of the items on teachers' TPACK, which was set as the acceptable level for this paper. Therefore, the study concludes that Lesotho teachers do use ICTs for teaching physical science even though their TPACK may be below average. Their low TPACK may be an indication that they used ICTs to get more information about the content, rather than for delivering the lessons. There is thus an urgent need to increase the support for teachers to maximise the use of ICTs for teaching.

With the inclusion of engineering disciplinary core ideas (DCIs), the Next Generation Science Standards (NGSS) position engineering as a new priority in K-12 science classrooms. This paper reports findings from the implementation of SLIDER, a problem-based learning 8th grade physical science curriculum that integrates engineering and physical science core ideas. As a culminating engineering design challenge, the SLIDER curriculum asks students to apply their understanding of energy, motion, and forces to design an automatic braking system for a robotic truck. The paper describes the curriculum and synthesizes findings from an array of data sources including student design interviews, written design recommendations, engineering notebooks, pre- and post-assessments, and teacher interviews to address two research questions: (1) To what extent and in what ways do students participating in the SLIDER curriculum engage in NGSS engineering DCIs: defining problems, developing solutions, and optimizing solutions? (2) To what extent and in what ways do students draw upon their understanding of science concepts as they engage in engineering design? Findings indicate variations in the degree to which students participating in the SLIDER curriculum engaged across the three NGSS engineering DCIs, with students generally demonstrating competency with regard to identifying and delimiting the engineering problem (ETS1.A) and, to varying degrees, developing solutions (ETS1.B) but experiencing more challenges engaging in the optimization of design solutions (ETS1.C). Findings also illustrate the degree to which students were able to apply their knowledge of relevant physical science core ideas (e.g., friction, force) as they developed and communicated their solutions. Implications of the findings for instruction, curriculum development, and assessment are discussed.

Physical sciences education comes with high expectations for learners to be successfully placed in tertiary institutions in related fields, and developing countries' aspirations to develop advanced and specialised skills to drive economies. However, some of the prevailing instructional strategies in science classrooms work to marginalise learners. This study explored access to effective inquiry-based practical work for physical sciences learners in two South African schools, through social cognitive and social justice lenses. Purposive sampling techniques were used to select an under-resourced high school and a well-resourced high school. Semi-structured interviews with two physical sciences teachers and open-ended observations were used to collect data in each of the schools for analysis through content analysis techniques. It came to light that the absence of practical examinations from the system of assessment resulted in an undervaluing of inquiry-based practical work in physical sciences classrooms. Additionally, instructional leadership practices did not support using this instructional strategy. The undervaluing of inquiry-based practical work marginalised learners, and the circumstances of limited access translated into a social justice agenda stemming from the high expectations associated with studying high school physical sciences. Recommendations are made to support inquiry-based practicals through the processes of assessment and tools for instructional leadership.

Background: Current reforms in K-12 STEM education call for integration between science, technology, engineering, and mathematics (STEM). Such integration of STEM disciplines at the K-12 level offers students an opportunity to experience learning in real-world, multidisciplinary contexts; however, there is little reported research about teachers' experiences in engaging in integrated STEM instruction. The purpose of this phenomenological multiple case study is to understand nine science teachers' first-time experiences in implementing integrated STEM curricular units in their middle school physical science classrooms. This study draws upon both classroom implementation data and teacher reflective interviews to illustrate different degrees of integrated STEM instruction and to understand teachers' challenges and successes with these varying approaches. Results: Our results indicate three distinct cases of integration within our sample that represent low, medium, and high degrees of STEM integration throughout curriculum implementations. Interviews with teachers from each case revealed three themes that varied across teachers' experiences: the nature of integration, choosing between science and engineering, and student engagement and motivation. Teachers in all three cases were challenged to make explicit connections between science, engineering, and mathematics while simultaneously maintaining a motivating and engaging context for their students throughout their instruction. Further, it appears that the degree of STEM integration that occurs in instruction may be related to teachers' ability to make explicit connections between the disciplines. Conclusions: The work presented here informs educational researchers, policy makers, and K-12 STEM educators that there are several challenges when it comes to implementing new STEM initiatives in K-12 education. Although this work is limited to middle school physical science teachers' experiences with first-time STEM instruction, many of the identified themes are not content-specific; therefore, this work may shed light on general struggles that are common to educators who are integrating across content disciplines for the first time.

Now in its fifth year, PR[superscript 2]EPS is a National Science Foundation funded initiative designed to recruit high school students to attend college majoring in the physical sciences, including engineering and secondary science education, and to help ensure their retention within these programs until graduation. A central feature of the recruitment effort is a free, one-week residential summer science camp for high school students. This report describes the rationale for using a camp as a recruitment tool as well as the camp structure. Two focus questions are addressed: 1) How successful is the camp at providing a learning environment where participants can share their enthusiasm for science and brainstorm and apply solutions to challenging scientific tasks with their peers? 2) How successful is the camp at recruiting students into the physical sciences at this college? Quantitative data from pre- and post-camp and longitudinal surveys showing that campers are pursuing degrees in the sciences are substantiated in a framework of qualitative data collected during the summer of 2007 by a non-participant observer. Faculty similarly concerned with motivating high school students to major in the physical sciences and science education should find the report useful as several indicators show that most campers continue on their trajectory towards degrees in the sciences. (Contains 4 figures.)

The post-apartheid National Physical Science Curriculum was implemented for the first time in South Africa in grade 10 during 2006. A variety of new textbooks for grade 10 have been published. This study was a comparative analysis of three popular textbooks, one prepared to support the previous curriculum, and two prepared for the new curriculum. The study employed an eclectic theoretical approach and a mixed mode (qualitative and quantitative) methodology. The comparative analysis of the three textbooks showed that the old textbook presented pure, decontextualised physical science knowledge; presented conventional academic "hard" science knowledge as strongly separated from the real world; and assumed that English was the first language of students. It emphasized factual and conceptual knowledge that students must remember and understand. It was underpinned by an objectivist epistemology and a rationalist philosophy of knowledge. One of the new textbooks was similar to the old. The other new textbook was inclusive, and presented science knowledge using a popular format and an interactive style. In addition to academic science knowledge, utilitarian knowledge was also presented. There was also an emphasis on factual and conceptual knowledge that students must remember and understand. The boundaries between science and the real world were weakened, and an obvious attempt to incorporate indigenous knowledge in the textbook was made. The new textbook seemed to be less mono-cultural, white, Eurocentric, and male-centered. Various language tools mediated English for second-language learners. In addition, it situated science knowledge in social,historical, and cultural experiences that students could identify with. Meta-cognitive reflection on the acquisition of academic and social competencies was consistently expected and there was also an expectation for higher cognitive processes, such as, analysis and evaluation. The textbook was underpinned by a social-constructivist epistemology and a humanistic philosophy of knowledge. The findings of this study support the conclusion that the new textbooks differ in terms of their potential to improve access to science for groups which have historically been marginalized. (Contains 2 figures, 8 tables and 2 footnotes.)

The Science Belief Test is an online instrument comprised of 47 statements that require true or false responses and request written explanations to accompany these responses. It targets topics in chemistry, physics, biology, earth science, and astronomy and was initially designed to assess preservice elementary teachers' beliefs about general science content. A set of responses for six of the physical science items targeting force/gravity and physical/chemical change was selected for analysis from 305 respondents. Written explanations were coded into three general categories: (1) correct explanation, (2) incorrect explanation, (3) guess or uninterpretable. The correct response rates for the explanations were compared to the correct response rates that were based on the accompanying true or false answers. The explanations were further analyzed and coded into specific categories that included alternative and naive conceptions. Correct response rates, when analyzed from the true/false or written explanations, were low (less than 60%) for five of the six items. Naive beliefs and/or misconceptions were prevalent for each of these five items, and understanding that students may hold these beliefs prior to instruction may provide teachers with useful information for the purpose of improving instruction. (Contains 2 tables.)

This article introduces an online jigsaw model for preservice teachers' science content learning. Following a description of the model and its developmental genesis, analysis of an external proficiency measure serves to evaluate the model's validity. Data stem from a sample of 333 students who completed physical science courses in either a face-to-face or online setting, and who participated in a state-mandated certification exam. An independent samples t-test of means of scores indicates that the two groups are not significantly different from each other. Based on this preliminary finding and the high student retention rate across semesters, the online jigsaw model appears to be a viable alternative to on-campus settings. (Contains 4 figures and 3 tables.)

Despite the growing popularity of robotics competitions such as FIRST LEGO League, robotics activities are typically not found in regular K-12 classrooms. We speculate that, among other reasons, limited adoption is due to the lack of empirical evidence demonstrating the effect of robotics activities on curricular goals. This paper presents a mixed methods study exploring the impact of a summer robotics camp on middle school students' physics content knowledge and scientific inquiry skills. It was found that the camp enhanced students' physics content knowledge but failed to improve their skills in conducting scientific inquiry. Qualitative data provided an explanation of the findings.

Teachers contribute enormously to a positive social climate in science classes, particularly through their communication with students. In the study described in this article, a questionnaire [The Teacher Communication Behaviour Questionnaire (TCBQ)] developed by She and Fisher (2000) was used. TCBQ can be used to assess students' perceptions of science teachers' interpersonal communication behaviours in their classroom learning environments. TCBQ has five scales: Challenging, Encouragement and Praise, Non-Verbal Support, Understanding and Friendly, and Controlling. The TCBQ was used with a large sample of university students in Turkey. Girl students perceived more of these communication behaviours in their teachers than did the boy students. There were statistically significant differences (p less than 0.0001) on four of the five scales of the TCBQ between teachers' gender. Statistically significant differences were not found among different grade classes. Teachers in biological and chemistry science classrooms exhibited more favourable behaviour toward their students than did those in physical science classrooms. (Contains 4 tables.)

Important science phenomena--such as atomic structure, evolution, and climate change--are often hard to observe directly. That's why an important scientific practice is to use scientific models to represent one's current understanding of a system. Using models has been included as an essential science and engineering practice in the "Next Generation Science Standards" (NGSS Lead States 2013). This article describes an instructional unit that uses an iterative process of generating, critiquing, and revising complex scientific models that address sea level rise.

This study reports changes in kindergarten students' understanding of magnets after participating in a series of hands-on, inquiry-based lessons. The lessons focused on the dipole nature of magnets and employed a visual representation of a magnet as an arrow for the kindergarten students. This dipole model was used to describe how magnets interact with each other and how they interact with steel objects (i.e., magnetization). Many students adopted this dipole model of magnets and were able to use it to describe how multiple magnets would interact and how magnetized paperclips would interact with magnets and with each other. (Contains 2 figures.)

The grade three curriculum set out by the British Columbia Ministry of Education has four categories for science: Processes of Science, Life Science, Physical Science, and Earth and Space Science. Within each of these categories there are numerous topics to teach. For example, the physical science curriculum requires students to learn about magnetism, energy, matter, and sound. In addition, students are expected to be able to classify, demonstrate, describe, create, distinguish, identify, evaluate, classify, compare, and infer different aspects of each of these topics as needed. This is an overwhelming task and covering all the material in a meaningful way, so that every child develops and expands their concepts, is a challenge, to say the least. In the Integrated Resource Package that outlines the curriculum for life science, students are to learn about the life cycles of different plants and animals and compare them. Students are to learn what each needs for survival, discuss the environment, fossils, endangerment, and extinction. In an effort to tie these topics together, the author decided to introduce the water cycle as a basis for understanding what students are required to learn about plants and animals. The unit presented in this article is based on Kieran Egan's "mythic framework". The author's aim is to introduce the students to how plants and animals (including humans) are connected to the water cycle and explore these topics in depth in later units. As future science units will explore these topics in greater detail, this unit will provide a basis for future learning. Interconnectedness is the main concept to be developed in this unit.

In many countries there remain substantial sex differences in enrolments in elective science courses, despite concerted efforts in recent years to alleviate them. This paper explores the reasons for these differences by comparing models of male and female enrolment intentions in elective courses in biology, chemistry and physics. The models are based on responses from approximately 450 students from 5 Australian high schools. First, a theoretical model, the Science Enrolment Model, was derived from Eccles and colleagues' General Model of Academic Choice. Students' responses were then used to develop empirical models of enrolment intentions in the three elective courses. Analyses for the models were conducted using the LISREL "mean structures" extension. Sex differences in the dependent variables in the models were then attributed to the relevant sets of independent variables. Substantial sex differences were identified in measures of perceived career value, interest and performance expectations in all three models which explained between 70% and 82% of the sex differences in enrolment intentions. (Contains 1 table and 5 figures.)

This study examines the development of mental models of air by kindergarten students after completing a series of hands-on, inquiry-based science lessons. The lessons focused on two properties of air: (1) that air takes up space and (2) that it is made of particles ("balls of air"). The students were interviewed about their ideas of air and about phenomena involving air before and after the lessons. From the lessons, the students gained experiences and vocabulary to draw upon to make more sophisticated arguments about phenomena involving air, often employing the "balls of air" model in their explanations.