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The purpose of this study is to increase the understanding about undergraduate life science students' conceptions concerning the role of photosynthesizing plants in the ecosystem, utilizing a network analysis method. Science learning requires the integration and linking of abstract and often counterintuitive concepts successfully into multifaceted networks. The quality of these networks, together with their abilities to communicate via the language of science, influences students' success in academic, verbal problem-solving tasks. This study contributes to investigating students' understanding, utilizing a modern network analysis method in exploring first-year university life science students' written answers. In this study, a total of 150 first-year life science students answered two open-ended tasks related to the role of photosynthesizing plants in the ecosystem. A network analysis tool was used in exploring the occurrence of different-level science concepts and the interrelatedness between these concepts in students' verbal outputs. The results showed that the richness of concept networks and students' use of macro-concepts were remarkably varied between the tasks. Higher communicability measures were connected to the more abundant existence of macro-concepts in the task concerning the role of plants from the food-chain perspective. In the answers for the task concerning the role of plants regarding the atmosphere, the students operated mainly with single facts, and there were only minor interconnections made between the central concepts. On the basis of these results, the need for more all-encompassing biology teaching concerning complex environmental and socio-economic problems became evident. Thus, methodological and pedagogical contributions are discussed.

Learning the wave-particle dualism of electrons and photons plays a central role in understanding quantum physics. Teaching it requires that the teacher is fluent in using abstract and uncommon terms. We inspect the lexical structures of pre-service teachers' declarative knowledge about the wave-particle dualism of electrons and photons in the context of double-slit interference. The declarative knowledge is analyzed in the form of a lexical network of terms. We focus on lexical structures because, in teaching and learning, knowledge is communicated mostly through lexical structures, i.e., by speaking and writing. Using the lexical networks, we construct the lexicons used by pre-service teachers to express their knowledge of electrons and photons in the context of double-slit interference. The lexicons consist of eight different key terms, each representing a set of closely-related or synonymous terms. The lexicons by 14 pre-service teachers reveal remarkable variation and differences, and are strongly context-dependent. We also analyzed lexicons corresponding to two didactically-oriented research articles on the same topic and found that they also differ. Lexicons paralleling both texts are found among the pre-service teachers' lexicons. However, only some of the pre-service teachers use such rich vocabulary as would indicate multi-faceted understanding of quantum entities.

Relational interlinked dependencies between concepts constitute the structure of abstract knowledge and are crucial in learning conceptual knowledge and the meaning of concepts. To explore pre-service teachers' declarative knowledge of physics concepts, we have analyzed concept networks, which agglomerate 12 pre-service teacher students' representations of the key elements in electricity and magnetism. We show that by using network-based methods, the interlinked connections of nodes, locally and globally, can be analyzed to reveal how different elements of the network are supported through their connections to other nodes in the network. Nodes with high global connectivity initialize contiguous concept patchworks within the network and are thus most often found to be abstract, general, and advanced concepts. Locally cohesive concepts, on the other hand, are nearly always auxiliary supporting concepts, related to specific textbook-type experiments and model-type conceptional elements. Comparisons of group-level knowledge and individual pre-service teacher students' knowledge in the form of networks shows that while in group-level the aggregated knowledge is expert-like, at the individual level pre-service teacher students possess only a fraction of that knowledge.

Supporting teacher candidates' learning of coherent and well-ordered content knowledge is one of the most important educational aims in subject teacher education. To reach this aim, teacher educators need suitable tools to enhance the formation of such knowledge. In this article, we present an analytical framework to examine conceptual knowledge, meaning the ability to define the relevant concepts pertaining to a task; relational knowledge, i.e., the ability to consider interrelations between the concepts; and strategic knowledge, i.e., the ability to use the knowledge by providing (experimental or modeling) procedures, which build new knowledge. A sample analysis of 16 teacher candidates' written reports is presented to illustrate how this framework can be used. The aim of the study was to reveal what kind of variation in teacher candidates' content knowledge can be found. This study suggests that teacher candidates' written reports can reveal remarkable differences in the epistemic dimensions of content knowledge. The framework shows the differences among the teacher candidates as well as produces information for teacher educators of the critical aspects, when and where to intervene, and where to focus using different teaching practices.

We present a method to analyse how pre-service science teachers relate events, ideas, characters and deeds in history of science and in cultural and general history. A group of 25 students presented their views they deemed to be of importance in history of science, culture, society and politics in era between 1550 and 1850. The sample is based on students' study reports and analysed by using network analysis. We show how students' knowledge of history of science and history in general are organised around certain famous characters, ideas, events and institutions, thus revealing the phenomenon of accumulation of fame; the Matthew effect in action.

The concepts of electricity and magnetism in physics are complex and demanding to learn because their meaning builds through several different phenomenological areas. Each of the phenomenological areas adds a certain facet of the meaning of the concept. All standard physics textbooks discuss at least 1) force, 2) energy and work, and 3) electric charge and current, which are different phenomenological facets of the field and which also are implicitly covered in instruction. It is of interest to ask, how these three facets are actually reflected in university students' declarative (expressed and communicated) knowledge of electric and magnetic field concepts. Here this problem is addressed using recently introduced concept networks as a research tool. Using these concept networks, pre-service physics teachers have represented their views how electric and magnetic field concepts are linked to other concepts and conceptual elements in electricity and magnetism. The results suggest that more extensive is the students' basis of content knowledge the more balanced are the facets, while students with less extensive basis of content knowledge tend to favour forcebased understanding of the electric and magnetic fields. The implications of the findings on teaching and instruction are discussed.

We analyze here how pre-service teachers explicate their views about the waveparticle duality of photons and what role it plays in their arguments supporting the quantum nature of light. The data for the analysis is provided by 12 written reports about the double-slit experiment with feeble light. The analysis is based on constructing semantic networks corresponding to pre-service teachers’ written texts. Contingency-like associative correlation between word-pairs is used to differentiate between word-pairs, where associations of two terms or words is systematic. Such associations indicate connections, which are significant for key term vocabularies in construction of inferences and arguments. Based on that information of the key vocabulary we then construct the structure of pre-service teachers’ argument for the nature of the photon and its wave-particle duality, in the form of directed argument graphs (DAGs). The results show that argument structures in four to six out of 12 cases meet the goals set for pre-service teacher education. In these cases, experimental aspects and wave-particle duality play an important role in the pre-service teachers’ argument and its structure. [ABSTRACT FROM AUTHOR]

Good conceptual understanding of physics is based on understanding what the key concepts are and how they are related. This kind of understanding is especially important for physics teachers in planning how and in what order to introduce concepts in teaching; connections which tie concepts to each other give direction of progress--there is "flux of information" so that what was learned before provides the basis for learning new ideas. In this study, we discuss how such ordering of concepts can be made visible by using concept maps and how they can be used in analysing the students' views and ideas about the inherent logic of the teaching plans. The approach discussed here is informed by the recent cognitively oriented ideas of knowledge organisation concentrating on simple knowledge organisation patterns and how they form the basis of more complex concept networks. The analysis of such "concept networks" is then very naturally based on the use of network theory on analysing the concept maps. The results show that even in well-connected maps, there can be abrupt changes in the information flux in the way knowledge is passed from the initial levels to the final levels. This suggests that handling the information content is very demanding and perhaps a very difficult skill for a pre-service teacher to master.

In physics teacher education, one of the recurrent themes is the importance of fostering the formation of organised and coherent knowledge structures, but a simple shared understanding of what coherence actually means and how it can be recognised, is not easily found. This study suggests an approach in which the coherence of students' views about the relatedness of physics concepts can be identified and evaluated. Six pre-service physics teachers presented their understanding of the relatedness of physics concepts in the form of specially designed concept maps in which experimental or modelling procedures were required as links between physics concepts. The acceptability of the links was evaluated by using four criteria for epistemic analysis introduced in this study. The weighted values describing the maps' structural features were calculated, and finally, the cases were compared and the differences between them were discussed. The results show that the epistemic analysis of links affects remarkably to the acceptability of knowledge and thus also the coherence of such knowledge. The highest criterion set for acceptability seems to be very demanding to fulfil and even in the advanced level of studies only a fraction of students manage to reach it. The cases examined here show that the knowledge structures are partly fragmented and not as coherent as one would have expected them to be.

Teaching and learning the language of science is an important part of science education. Learning the vocabulary of science plays a key role in learning the language of science. The meaning of abstract scientific terms builds on their connections with other terms and how they are used. In this research, we study pre-service physics teachers' physics-related vocabularies and investigate how rich a vocabulary they use and what similarities and differences there are in their vocabularies regarding electrons and photons. We investigate the connectedness of physics terms by categorizing them according to their role in explaining quantum physics and carry out a lexical network analysis for N=60 written reports. The analysis shows that vocabularies do not share much similarity and the reports reflect narrow images of photons and electrons. We conclude that science teacher education needs to pay attention to explicit teaching of the language of science for pre-service teachers. [ABSTRACT FROM AUTHOR]

Students' understanding of scientific conceptual knowledge is often represented as an interlinked web of concepts, principles, laws and models. A long-standing problem in educational research is identifying the key concepts that are central in producing cohesion and contingency in such a web. Here we use network analysis to examine students' representations of the relatedness of physics concepts in the form of concept maps, and suggest how key concepts can be identified. The concept maps are analysed as weighted networks, where nodes are concepts or other conceptual elements and links represent different types of epistemically justified connections between concepts. The importance of concepts in providing cohesion is operationalized through subgraph centrality ${\mathrm {SC}}$, while their importance in providing contingency is operationalized through communicability betweenness centrality ${\mathrm {BC}}$. Key concepts are identified through importance ranking ${\mathrm {IR}}$, which is the geometric mean of ${\mathrm {SC}}$ and ${\mathrm {BC}}$, suitably normalized. We show that ${\mathrm {IR}}$ is able to reliably identify a set of nodes that are the most important in all networks. In order to effect a more detailed comparison of different concept networks, a similarity measure is developed, which pays attention to subtle but important differences in the importance rankings of concepts in different concept networks. [ABSTRACT FROM AUTHOR]