Classification of Chemical Substances using Particulate Representations of Matter: An analysis of student thinking

We applied a mixed‐method research design to investigate the patterns of reasoning used by novice undergraduate chemistry students to classify chemical substances as elements, compounds, or mixtures based on their particulate representations. We were interested in the identification of the representational features that students use to build a classification system, and in the characterization of the thinking processes that they follow to group substances in different classes. Students in our study used structural and chemical composition features to classify chemical substances into elements, compounds, and mixtures. Many of the students’ classification errors resulted from strong mental associations between concepts (e.g., atom–element, molecule–compound) or from lack of conceptual differentiation (e.g., compound–mixture). Strong concept associations led novice students to reduce the number of relevant features used to differentiate between substances, while the inability to discriminate between two concepts (conceptual undifferentiation) led them to pay too much attention to irrelevant features during the classification tasks. Comparisons of the responses to classification tasks of students with different levels of expertise in chemistry indicate that some of these naïve patterns of reasoning may be strengthened by, rather than weakened by, training in the discipline.     

A Macro–Micro–Symbolic Teaching to Promote Relational Understanding of Chemical Reactions

The purpose of this research is threefold: (1) to identify the difficulties that Grade 10 students in a Lebanese school have that hinder their conceptual understanding at the micro–macro–symbolic interface in chemistry, (2) to investigate the effect of a macro–micro–symbolic teaching approach on students’ relational understanding of chemical reactions, and (3) to characterize students’ conceptual profiles regarding their understanding of chemical reactions in terms of macro, micro, symbolic levels and the relations among them, at the end of the teaching sequence. Forty six 10th graders from two sections participated in the study. A student-centered approach was followed in both sections based on constructivist pedagogy. Hence the teacher played the role of a facilitator who guided students in a meaning making inductive learning process, through questioning, monitoring, validating, and clarifying ideas. Instruction in the experimental group was characterized by macro–micro–symbolic teaching that focuses on the interplay between the levels, integrates various representations, and engages students in an epistemic discourse about the nature of knowing in chemistry. Data sources for the study included a pre-test and two post-intervention tasks: a post-test and a concept map task, in addition to interviews with selected students from both sections. Findings indicated that macro–micro–symbolic teaching enhanced students’ conceptual understanding and relational learning of chemical reactions. Besides, four assertions related to students’ conceptual and epistemological thinking in response to the different teaching approaches are presented. Implications for instruction and for teacher education programs, as well as recommendations for further research, are discussed in light of these findings.     

Exploring Tertiary Students' Understanding of Covalent Bonding

There has been little research into learners' mental models of chemical bonding at any level, let alone the tertiary level. Undergraduate and graduate students encounter a plethora of sophisticated and highly abstract mental models for chemical bonding, and this study sought to investigate if there are preferred mental models for the concept of covalent bonding for secondary, undergraduate, and graduate chemistry learners. In particular, it was of interest to see whether exposure to increasingly sophisticated mental models at different points in a chemistry education showed up in patterns of preference and use of models in interpreting common physical properties and phenomena. The study revealed that, despite evidencing expertise in a number of highly complex and mathematically sophisticated mental models, tertiary students, including graduates (MSc and PhD), show a strong preference for simple realistic mental models. Furthermore, the students struggled to use their mental models to explain the physical properties of covalently bonded substances.     

The emerging role of CD-ROMs in teaching chemistry

Learning chemistry requires students to relate chemical equations and other symbolic notation both to molecular or atomic events and to macroscopic laboratory observations and data. Traditionally, textbooks have provided symbolic notation with minimal pictures of either microscopic events or macroscopic events leaving the teacher and student to conjure these pictures from words. This paper describes the design of several CD-ROMs with very different strategies and focus for teaching general chemistry with large databases of visual information. Teacher tools for preparation facilitate the planning of more hands-on laboratory experiences and live demonstrations to develop laboratory observation skills. Presentation materials provide animations of abstract microscopic events and concepts to help teachers explain these molecular and atomic events. Students improve observation skills in laboratories with supplemental computer tutorials that mimic the decision making required for laboratory tasks in a virtual laboratory, but students reinforce the experience and learn techniques with practice in a real laboratory. New college textbooks on CD-ROM, that integrate the molecular animations and laboratory experiments with the introduction of new terms and symbolic representations, portend large changes in all textbooks.     

Connecting Levels of Representation: Emergent versus submergent perspective

Chemical phenomena can be described using three representation modes: macro, submicro, and symbolic. The way students use and connect these modes when solving conceptual problems was studied, using a think‐aloud interview protocol. The protocol was validated through interviews with six faculty members, and then applied to four graduate and six undergraduate chemistry students. We used a ‘levels of complexity’ framework to analyse responses: the macro and symbolic modes were considered system‐level representations, and the submicro mode a component‐level representation. We found that faculty members thought of system‐level properties as emerging from mechanistic interactions between particles on the component level—an emergent perspective. In many cases, the students either failed to connect the system and component levels, or thought of system‐level properties as guiding the behaviour of particles on the component level—a ‘submergent’ perspective. Some students used their familiarity with a symbolic equation describing the behaviour of a substance as the starting point of a thought process that leads them to impose mechanistically unwarrantable behaviour upon its particles. We concluded that a submergent perspective inhibits students from confronting their misconceptions regarding particle behaviour, and explains why students are often able to correctly solve algorithmic problems while failing to solve conceptual ones. It is suggested that the directionality of connecting particle behaviour to system‐level properties should be emphasized in teaching.     

Investigation of chemistry graduate teaching assistants' teacher knowledge and teacher identity

Graduate students play an integral role in undergraduate chemistry education at doctoral granting institutions where they routinely serve as instructors of laboratories and supplementary discussion sessions. Simultaneously, graduate teaching assistants (GTAs) balance major research and academic responsibilities. Although GTAs have substantial instructional facetime with large numbers of undergraduate students, little is known about their conceptions of teaching or their identities as teachers. To investigate the knowledge that GTAs have regarding teaching in this unique context, their teaching identities, and how these developed, we conducted 22 interviews with graduate students from several universities at various levels in their graduate school career using a modified Teacher Beliefs Interview. Interviews were analyzed for two overarching teacher learning constructs: teacher knowledge and teacher identity. We characterized chemistry GTAs' teacher knowledge and identity and determined major influencing factors. We found that chemistry GTAs often identified as a tutor or lab manager, which hindered their self-investment in developing as teachers. The results presented herein contribute to an understanding of GTAs' teacher knowledge, teacher identity, and their teaching context, from which training can be designed to best support GTA development.     

Student learning outcomes and attitudes when biotechnology lab partners are of different academic levels

The North Carolina State University Biotechnology Program offers laboratory-intensive courses to both undergraduate and graduate students. In "Manipulation and Expression of Recombinant DNA," students are separated into undergraduate and graduate sections for the laboratory, but not the lecture, component. Evidence has shown that students prefer pairing with someone of the same academic level. However, retention of main ideas in peer learning environments has been shown to be greater when partners have dissimilar abilities. Therefore, we tested the hypothesis that there will be enhanced student learning when lab partners are of different academic levels. We found that learning outcomes were met by both levels of student, regardless of pairing. Average undergraduate grades on every assessment method increased when undergraduates were paired with graduate students. Many of the average graduate student grades also increased modestly when graduate students were paired with undergraduates. Attitudes toward working with partners dramatically shifted toward favoring working with students of different academic levels. This work suggests that offering dual-level courses in which different-level partnerships are created does not inhibit learning by students of different academic levels. This format is useful for institutions that wish to offer "boutique" courses in which student enrollment may be low, but specialized equipment and faculty expertise are needed.     

Emergence,Learning Difficulties,and Misconceptions in Chemistry Undergraduate Students’ Conceptualizations of Acid Strength

Philosophical debates about chemistry have clarified that the issue of emergence plays a critical role in the epistemology and ontology of chemistry. In this article, it is argued that the issue of emergence has also significant implications for understanding learning difficulties and finding ways of addressing them in chemistry. Particularly, it is argued that many misconceptions in chemistry may derive from students’ failure to consider emergence in a systemic manner by taking into account all relevant factors in conjunction. Based on this argument, undergraduate students’ conceptions of acids, and acid strength (an emergent chemical property) were investigated and it was examined whether or not they conceptualized acid strength as an emergent chemical property. The participants were 41 third- and fourth-year undergraduate students. A concept test and semi-structured interviews were used to probe students’ conceptualizations and reasoning about acid strength. Findings of the study revealed that the majority of the undergraduate students did not conceptualize acid strength as an emergent property that arises from interactions among multiple factors. They generally focused on a single factor to predict and explain acid strength, and their faulty responses stemmed from their failure to recognize and consider all factors that affect acid strength. Based on these findings and insights from philosophy of chemistry, promoting system thinking and epistemologically sound argumentative discourses among students is suggested for meaningful chemical education.     

Perfecting Lessons Learned for Criminal Justice Online Graduate Education: Reflection,Integration, and Application

Criminal justice programs are seeing an increase in the number of online classes both at the graduate and undergraduate levels. At the graduate level, criminal justice online education requires students to achieve mastery of higher ordered thinking and advanced analytic skills. Some students may believe that online education is simply a matter of reading postings and writing simple responses to queries. In order to counter the view that modern online courses, particularly those at the graduate level, are not academic enough, online graduate faculty must find ways to engage students through useful course design and meaningful assessments that promote deep learning. Such engagement requires faculty and students to show reflection in design as well as the integration and application of course materials in a consistent and significant way. This paper will discuss our attempts to reframe graduate criminal justice online classes in order to enhance student engagement and, ultimately, their deeper learning.     

Quantitative skills as a graduate learning outcome: exploring students’ evaluative expertise

In the biosciences, quantitative skills are an essential graduate learning outcome. Efforts to evidence student attainment at the whole of degree programme level are rare and making sense of such data is complex. We draw on assessment theories from Sadler (evaluative expertise) and Boud (sustainable assessment) to interpret final-year bioscience students’ responses to an assessment task comprised of quantitative reasoning questions across 10 mathematical and statistical topics. The question guiding the study was: do final year science students graduate knowing the quantitative skills that they have, and knowing the quantitative skills that they do not have? Confidence indicators for the 10 topics gathered students’ perceptions of their quantitative skills. Students were assigned to one of four categories: high performance-high confidence; low performance-low confidence; high performance-low confidence; or low performance-high confidence – with those in the first two categories demonstrating evaluative expertise. Results showed the majority of students effectively evaluated their quantitative skills as low performance-low confidence. We argue that the application of evaluative expertise to make sense of this graduate learning outcome can further the debate on how assuring graduate learning outcomes can enhance student learning.     

The Teaching of Writing in Social Work Education:

Though social work educators at the graduate and undergraduate level require their students to write much and often, the quality of writing of many recent graduates appears to be inadequate for meeting the contemporary demands of everyday practice in social work settings or interdicsiplinary arenas. In order to prepare more fully social work students for addressing contemporary social issues and for serving their clients, social work educators in the 1990s could draw upon the expertise of those composition teachers who have devised approaches to the teaching of writing that take into account the special demands of a given profession or discipline. The authors reflect on their application of such an approach in three social work programs - two at the graduate level and one at the undergraduate level.     

Proposing a center on aging and well-being: Research,education, and practice considerations

ABSTRACT

This environmental scan aimed to discover research interests and educational needs of faculty, graduate, and undergraduate students to inspire research, education, and practice in the development of a center on aging and well-being for older adults. The scan consisted of a search of university faculty and researchers regarding research on aging; a survey of graduate students and faculty about interests in aging research and needs of undergraduate students; and key informant interviews. Results offer a conceptualization based on the pillars of research, education, and practice. An inventory of researchers with various levels of expertise and interested in aging was created. Participants offered their perceptions of strengths, as well as challenges and strategies for success. These results will be a catalyst for planning and successful development of a center on aging and well-being. This article addresses a gap in the literature and will assist others undertaking a similar initiative in various geographical and cultural contexts.     

Constructing a graduate career future: Working with Bourdieu to understand transitions from university to employment for students from working‐class backgrounds in England

In high participation systems of higher education, the link between undergraduate study and progression to graduate employment is increasingly tenuous. One response is a growing emphasis on the development of employability skills and preparing students to take advantage of future opportunities as part of university study. This paper uses a Bourdieusian‐based conceptualisation of graduate capitals, combined with a concern for the psycho‐social dimensions of classed experience, to consider transitions through university and into employment for students from working‐class backgrounds in England, drawing on data from a study of students who attended the two universities in Bristol UK. It is argued that the assemblage of capitals that make up graduate capital could be seen as constituting a form of symbolic capital with magical powers, that hides the power relations involved in successful progression to graduate futures. While the move from university into work is more prolonged and precarious for students from all backgrounds, access to the resources that enable the development and mobilisation of graduate capitals, along with psycho‐social dimensions of class, create additional challenges for the development of viable graduate career identities for working‐class students such as those discussed in this paper. The paper concludes by noting implications for policy and practice.     

Concept maps about chemical equilibrium and students' achievement scores

The purpose of this study was to examine relationships between structural characteristics of students' concept maps about chemical equilibrium and independent measures of their achievement in chemistry. Fifty students in 1991 and seventy students in 1992 completed a concept-mapping task using twenty-four specified concepts. Using similarities in concept map structure, based on the presence or absence of linked pairs of concepts, non-metric multidimensional scaling (MDS) was used to plot the location of the concept maps in coordinate space. The distribution of maps was based on differences in their structure, but also reflected levels of student achievement on independent tests. The relationship between the coordinate location of each student's maps and his or her test scores on independent chemistry achievement tests was sought by canonical correlation analysis of the 1991 data set. This revealed significant relationships between the MDS coordinates and test scores of recall of knowledge and its application. Multiple regression analysis of sixty-one students' maps from the 1992 data set against their percentile rank scores on a national chemistry quiz revealed significant relationships. The results are interpreted as revealing structural differences in conceptual organisation about chemical equilibrium among students with different levels of achievement and thus relative expertise in the domain. The significant relationship between map structure and cognitive process scores in chemistry also supports the view that the organisation of declarative knowledge influences its accessibility in cognitive tasks.     

Heuristic Reasoning in Chemistry: Making decisions about acid strength

The characterization of students’ reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more analytical ways of thinking. The central goal of this qualitative study was thus to investigate heuristic reasoning as used by organic chemistry college students, focusing our attention on their ability to predict the relative acid strength of chemical compounds represented using explicit composition and structural features (i.e., structural formulas). Our results indicated that many study participants relied heavily on one or more of the following heuristics to make most of their decisions: reduction, representativeness, and lexicographic. Despite having visual access to reach structural information about the substances included in each ranking task, many students relied on isolated composition features to make their decisions. However, the specific characteristics of the tasks seemed to trigger heuristic reasoning in different ways. Although the use of heuristics allowed students to simplify some components of the ranking tasks and generate correct responses, it often led them astray. Very few study participants predicted the correct trends based on scientifically acceptable arguments. Our results suggest the need for instructional interventions that explicitly develop college chemistry students’ abilities to monitor their thinking and evaluate the effectiveness of analytical versus heuristic reasoning strategies in different contexts.     

Motivating the learning of part-time taught-postgraduate students through pedagogy and curriculum design: are there differences in undergraduate teaching?

Interviews were conducted with 29 part-time taught postgraduate (TPg) students to determine forms of teaching and curriculum which motivated their learning. The study was conducted in an open exploratory manner to investigate the aspects of pedagogy or curriculum design which particularly motivated the TPg students which were in any way distinct from typical undergraduate teaching. As most of the TPg students were mature professionals working in a field connected to the course they had enrolled in, they were able to identify relevant knowledge, skills and abilities which ought to be included in the content or curriculum. This distinguishes them from typical undergraduate students. The TPg students appreciated in-class discussion so that they could share experiences and expertise. The interviewees preferred assessment tasks that related to their professional practice. Teaching and learning for TPg students should recognise the expertise of the students and draw upon it as a valuable learning resource.     

Supporting Knowledge Integration in Chemistry with a Visualization-Enhanced Inquiry Unit

This paper describes the design and impact of an inquiry-oriented online curriculum that takes advantage of dynamic molecular visualizations to improve students’ understanding of chemical reactions. The visualization-enhanced unit uses research-based guidelines following the knowledge integration framework to help students develop coherent understanding by connecting and refining existing and new ideas. The inquiry unit supports students to develop connections among molecular, observable, and symbolic representations of chemical reactions. Design-based research included a pilot study, a study comparing the visualization-enhanced inquiry unit to typical instruction, and a course-long comparison study featuring a delayed posttest. Students participating in the visualization-enhanced unit outperformed students receiving typical instruction and further consolidated their understanding on the delayed posttest. Students who used the visualization-enhanced unit formed more connections among concepts than students with typical textbook and lecture-based instruction. Item analysis revealed the types of connections students made when studying the curriculum and suggested how these connections enabled students to consolidate their understanding as they continued in the chemistry course. Results demonstrate that visualization-enhanced inquiry designed for knowledge integration can improve connections between observable and atomic-level phenomena and serve students well as they study subsequent topics in chemistry.     

A VERSATILE METHOD FOR SELECTION AND MONITORING OF SCIENCE STUDENTS

This article describes a recent study with undergraduate and post graduate chemistry students and concerns their understanding of the role of models in chemistry. The principal technique used was the semi‐structured workshop Interview Involving models. The study highlighted the value of this technique in Identifying concept difficulties in chemistry and in exploring students’ views on science education issues in general. The article considers the potential of the semi‐structured workshop interview and makes recommendations for its Inclusion into a wide variety of assessment and evaluation procedures in higher education.