Publications
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(2024) Journal of the Learning Sciences. Abstract
Background: In science, mechanistic explanations play a crucial role in elucidating phenomena, highlighting the significance of mechanistic reasoning in science education. Studies in this field offer conflicting views on childrens mechanistic reasoning, with some suggesting that children tend to use other non-mechanistic types of reasoning. Methods: We used a mixed methods exploratory research design to investigate the evaluation and construction of explanations by children in grades 26. Children were asked to construct explanations for a biological phenomenon and to evaluate mechanistic and non-mechanistic explanations for three other biological phenomena. Findings: Children who participated in this study could construct mechanistic explanations, even 2nd graders. Moreover, they accepted more mechanistic explanations than non-mechanistic ones and preferred them over others. Two epistemic criteria seem to contribute to this evaluation process: \u201cexplanatory power\u201d assists the children in differentiating between mechanistic and non-mechanistic explanations, and \u201cinformation accuracy\u201d leads them to reject explanations that contradict their prior knowledge. We found that the accuracy criterion is grounded in knowledge of biology and thinking tools such as thinking across levels. Contribution: Our results highlight the epistemic perspective that elementary school children adopt when evaluating mechanistic and non-mechanistic explanations of biological phenomena and their emerging potential for mechanistic reasoning.
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(2024) The Routledge Handbook of Causality and Causal Methods. 1st ed. p. 661-670 Abstract
One major goal of science education is to help students become scientifically literate. That is, enabling them to understand, evaluate, and use scientific information. Understanding the nature of scientific research and the ability to reason accordingly was indicated as essential to scientific literacy. Hence, the importance of promoting causal thinking, a central part of the scientific enterprise, was acknowledged in curriculums and standards. According to these standards, students should identify causal relationships, distinguish between correlation and causation, and provide mechanistic explanations for causal relationships. Science education research criticized school science for oversimplifying causality as a simple direct relationship between two entities and causal reasoning as the process of isolation and control of variables. Nonetheless, students encounter many difficulties once complex causal thinking is practiced in schools. In this chapter, I will focus on two major types of causal thinking addressed in science education research: pattern-seeking and reasoning about mechanisms. These were described as distinct epistemic activities aiming to find, evaluate, and explain causal relationships. I will discuss the challenges in pattern-seeking and mechanistic reasoning, how these challenges originate from the complex nature of scientific phenomena, and what solutions may be offered.
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(2024) Research in Science Education. Abstract
Mechanistic explanations, aiming to disclose details of entities and their activities, employ the act of unpacking which, inherently and paradoxically, produces explanatory gapspieces of undisclosed, undetailed mechanistic information. These gaps, termed explanatory black boxes, are often perceived as counterproductive to the teaching of mechanisms, yet are integral to it, and their cognizant use is a nuanced skill. Amidst the discourse on mechanistic reasoning in science education, this paper focuses on biology teachers perception of explanatory black boxes and the explicit discussion of them in their classroom. Using interviews with 11 experienced high-school biology teachers, we unraveled perceived affordances and constraints in teachers use of black boxes in the context of challenges in teaching mechanisms. Utilizing the pedagogical content knowledge (PCK) framework, we expose a nuanced interplay of considerations related to strategies, students, curriculum alignment, assessment, and orientation toward science teaching. A constant tension existedwith considerations supporting and opposing the use of both unpacking and black boxing as teaching strategiesboth within and between PCK components. In contrast, contemplating the explication of black boxes led teachers to illustrate this strategy as an intermediate one, attenuating constraints of both unpacking and black-boxing strategies while also promoting teachers ability to align curricular items and endorse student agency. Implications for teacher training are discussed, emphasizing the need to make teachers aware of the involvement of black boxes in mechanistic reasoning, and familiarize them with black-box explication as an intermediate strategy that can enrich their pedagogy.
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(2024) Science. 383, 6685, p. 826-828 Abstract
Education must go beyond only countering essentialist and deterministic views of genetics.
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(2024) International Journal of Science Education. 46, 17, p. 1826-1847 Abstract
Immunology, a complex and rapidly evolving biological field, serves dual educational goals: training healthcare professionals and immunologists as well as promoting immune literacy among laypeople. This study conducted a scoping review of the literature to explore different aspects of immunology education, examining various contexts, levels, and content areas, including cognitive and motivational challenges. In addition, analysis covered different teaching strategies and research methodologies. Eight hundred and seventy-four articles were screened, and 20 articles proceeded to full-text analysis. Notably, the majority of the analysed studies concentrated on undergraduate education, emphasising strategies for teaching immunology, with a heavy reliance on quantitative research methods. Teaching strategies that were influential for improving the knowledge of the students were, for example, using games, using simulations and visualisations, using hands on experiments and self-directed learning. The content of the reviewed articles primarily revolved around topics related to innate and adaptive immunity, basic immunology, and immune system diseases. There was less emphasis on advanced immunology and on addressing the inherent complexity of the subject and even less on methods to motivate students to engage with immunology. Practical implications and suggestions for future research are described considering both healthcare practitioner training and immune literacy for laypeople.
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(2023) Journal of Research in Science Teaching. 60, 4, p. 915-933 Abstract
Many studies have characterized students' difficulties in understanding and reasoning about scientific mechanisms. Some of those studies have drawn implications on teaching mechanisms and how to guide students while reasoning mechanistically. In this theoretical article, I claim that one component that has not garnered much attention in the science education literature, unlike other components of mechanistic explanations, is the black box construct, that is, missing mechanistic parts within mechanistic explanations (explanatory black box). By reviewing the literature on mechanisms and mechanistic explanations in the philosophy of science and cognitive psychology, I argue that explanatory black boxes are an inherent part of mechanistic explanations and that their recognition is essential for learning mechanisms, scientific literacy, and understanding the nature of science. Examples from biology education are provided as a case of a complex multileveled scientific field. In the absence of a pedagogical approach for teaching explanatory black boxes, I turn to studies and frameworks from computer science education that may guide educators on how to begin discussing this construct in the science classroom.
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(2023) International Journal of Science Education. 45, 9, p. 709-733 Abstract
The ability of school students to use health-related knowledge for their and their communitys needs is referred to as health literacy and is regarded as a combination of knowledge and motivational factors. In the case of cancer literacy, high-school students have some knowledge about risk factors, but not much is known about their understanding of the mechanisms by which these risk factors cause cancer. In addition, motivational factors, such as psychological perceptions of cancers, are not well-characterised in this population. Hence, data are insufficient to support the development of educational programmes for enhancing cancer literacy. We characterised 10th-grade students knowledge and illness perceptions using open questions and Brief Illness Perception Questionnaire and searched for an association between the two. We found that students have much more causal knowledge than mechanistic knowledge about cancer. We also found that the ability to reason about the mechanisms by which cancer develops is associated with the perceived severity of the disease. Thus, the mechanisms leading to cancer should be taught rather than focusing on risk factors. This study also provides evidence for a possible interplay between a specific type of knowledge (mechanistic) about a given phenomenon (cancer) and psychological perceptions of that phenomenon.
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(2022) 1 ed. Abstract
This edited volume presents the current state of the art of genetics education and the challenges it holds for teaching as well as for learning. It addresses topics such as how genetics should be taught in order to provide students with a wide and connected view of the field. It gives in-depth aspects that should be considered for teaching genetics and the effect on the students understanding. This book provides novel ideas for biology teachers, curriculum developers and researchers on how to confront the presented challenges in a way that may enable them to advance genetics education in the 21st century. It reviews the complexity of teaching and learning genetics, largely overlooked by biology textbooks and classroom instruction. It composes a crucial component of scientific literacy.
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(2022) Genetics Education. p. 71-86 Abstract
Understanding how genes affect traits is an important part of scientific literacy in the twenty-first century. However, studies have shown the challenges of teaching and learning these multilevel mechanisms. Research in science education has mapped some of the reasons for students difficulties and has explored possible approaches to overcoming them. Those studies have found that the way in which genes, proteins and the complexity of genetic mechanisms are presented to students is inadequate. By reviewing some of the literature in the field of genetics education, I identified three milestones in the progression toward a mechanistic understanding in genetics: (a) establishing a correct causal connection between genes and traits; (b) establishing an understanding of genesproteinstraits mechanisms, and (c) identifying points of regulation and understanding how environmental signals can modulate gene-to-trait mechanisms. In this chapter, I present the identification of these three milestones and propose novel scaffolds for moving along the progression of mechanistic understanding. I also discuss these milestones in the context of genetics learning progression and draw implications for teaching genetics and for future studies in the field.
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A Lighter Shade of Black Boxes: Students' Interpretations of the Distinction Between Black Box Explanations and Unpacked Mechanistic Explanations(2022) Proceedings of the 16th International Conference of the Learning Sciences - ICLS 2022. Chan C., Chinn C., Tan E. & Kali Y.(eds.). p. 43-50 Abstract
Scientific explanations rarely include all interactions and entities in a mechanism. Instead, some information is hidden in black boxes, keeping the focus on the explanation's essence. Studies show that navigating between black-box explanations and detailed mechanistic explanations perplexes students as they misunderstand the reasons for including or omitting mechanistic information. Therefore, we examined students' preference towards information allowing for the formation of either a black-box explanation or a detailed mechanistic explanation. Fifty-two 9th grade students read three scientific problems in three contexts. Students stated and justified their preference of information. Analysis revealed students based choices on problems' context and explanation's productivity. Students preferred black-box information when recognizing the need to make a prediction and detailed information when recognizing a need to control phenomena. Results suggest clear explanatory goals assist students' navigation between detailed and black-box explanations. This calls for a more explicit discussion around black boxes in the science classroom.
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(2021) Abstract
Many educational endeavors address the challenge of developing approaches, tools and platforms for introducing computational problem-solving skills, often referred to as computational thinking, into the school system. Plethora, a game-based platform, teaches the concepts and skills of computational problem solving, by means of graphically attractive logical challenges that are expressed in a natural language. It was developed at the Weizmann Institute of Science, in collaboration with The Israeli Center for Educational Technology. Plethora is used in schools across Israel and was selected as the leading tool for national school-level cyber competitions. In this panel, we will explain our approach towards computational problem solving, show how it is implemented with Plethora, present the scientific basis of Plethora, and finally show how Plethora can be extended to discuss computational models of scientific phenomena.
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(2021) ISLS Annual Meeting 2021 Reflecting the Past and Embracing the Future - 15th International Conference of the Learning Sciences, ICLS 2021. de Vries E., Ahn J. & Hod Y.(eds.). p. 107-114 Abstract
In genetics, a domain with a vast impact on citizens lives, mechanistic reasoning is challenging. In order to promote the ability to reason mechanistically in genetics, we should first understand what knowledge students need in order to be able to provide mechanistic explanations in this domain. In this study we interviewed undergraduate students studying toward a biological sciences degree and asked them to explain several complex genetic phenomena. We analyzed those interviews via two complementing perspectives a mechanistic perspective and a cognitive perspective for domain-specific reasoning. We identified the type of domain specific knowledge used by students for reasoning and their use of domain general principles for mechanistic reasoning. We found that domain specific knowledge is used to operationalize domain general principals such as identifying and unpacking entities and linking between different parts of the suggested mechanism. We also found that domain-specific knowledge is used for re-visiting ones own explanation.
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(2020) CBE Life Sciences Education. 19, 3, p. 1-13 ar37. Abstract
The idea of the interaction between genes and environment in the formation of traits is an important component of genetic literacy, because it explains the plastic nature of phenotypes. However, most studies in genetics education characterize challenges in understanding and reasoning about genetic phenomena that do not involve modulation by the environment. Therefore, we do not know enough to inform the development of effective instructional materials that address the influences of environmental factors on genes and traits, that is, phenotypic plasticity. The current study explores college students understanding of phenotypic plasticity. We interviewed biological sciences undergraduates who are at different stages of their undergraduate studies and asked them to explain several phenomena that involved phenotypic plasticity. Analysis of the interviews revealed two types of mechanistic accounts: one type described the interaction as involving the environment directly acting on a passive organism; while the other described the interaction as mediated by a sensing-and-responding mechanism. While both accounts are plausible, the second account is critical for reasoning about phenotypic plasticity. We also found that contextual features of the phenomena may affect the type of account generated. Based on these findings, we recommend focusing instruction on the ways in which organisms sense and respond.
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(2019) Journal of Research in Science Teaching. 3, p. 342-367 Abstract
Mechanisms are central in scientific explanations. However, developing mechanistic explanations is difficult for students especially in domains in which mechanisms involve abstract components and functions, such as genetics. One of the core components of genetic mechanisms are proteins and their functions. Students struggle to reason about the role of proteins while learning genetics and show limited ability to provide mechanistic explanations of genetic phenomena. In genetics education there are currently two competing theoretical frameworks regarding what domain-specific knowledge about proteins is important for reasoning about genetic mechanisms. One framework assumes knowledge about specific protein functions in the body, a tool kit of functions; the other framework assumes more abstracted knowledge about protein interactions that are common to all protein functions. These frameworks implicate different instructional frameworks: One offers to provide concrete examples of protein functions while the other offers a more general description of protein activity. Our aim in this study was to ascertain the ways in which students' reasoning about proteins' role in genetic phenomena (both familiar and novel) relates to the two theoretical frameworks. Toward this end we engaged 7th grade students in learning about proteins functions in the mechanisms underlying genetic traits using an online simulation environment that embodied key aspects of both frameworks. We analyzed students' responses to the final test questions in which they were asked to generatively reason about the underlying mechanisms of two novel genetic traits. Our findings suggest that students use proteins in their explanations mainly when they can explain the protein function and that knowledge about a few specific functions is insufficient to support conceptualization of new functions. Moreover, knowledge of general protein activities common to most functions is also insufficient. We suggest a new combined approach to supporting students' understanding of proteins' role in genetic mechanisms.
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(2018) CBE Life Sciences Education. 17, 3, 36. Abstract
Understanding genetic mechanisms affords the ability to provide causal explanations for genetic phenomena. These mechanisms are difficult to teach and learn. It has been shown that students sometimes conceive of genes as traits or as trait-bearing particles. We termed these "nonmechanistic" conceptions of genetic phenomena because they do not allow the space required for a mechanism to exist in the learner's mind. In this study, we investigated how ninth- and 12th-grade students' conceptions of genetic phenomena affect their ability to learn the underlying mechanisms. We found that ninth- and 12th-grade students with nonmechanistic conceptions are less successful at learning the mechanisms leading from gene to trait than students with mechanistic conceptions. Our results suggest that nonmechanistic conceptions of a phenomenon may create a barrier to learning the underlying mechanism. These findings suggest that an initial description of a phenomenon should hint at a mechanism even if the mechanism would be learned only later.
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(2018) Education Sciences. 8, 3, 110. Abstract
In genetics education, symbols are used for alleles to visualize them and to explain probabilities of progeny and inheritance paradigms. In this study, we identified symbol systems used in genetics textbooks and the justifications provided for changes in the symbol systems. Moreover, we wanted to understand how students justify the use of different symbol systems when solving genetics problems. We analyzed eight textbooks from three different countries worldwide. We then presented a genetics problem to eight 9th-grade students and probed their justifications for the use of different symbol systems. Our findings showed that there is no one conventional symbol system in textbooks; instead, symbol systems are altered along and within textbooks according to the genetic context. More importantly, this alteration is not accompanied by any explicit explanation for the alteration. Student interviews revealed that some students were able to identify the genetic context of each symbol system, whereas others, who were unable to do so, provided justifications based on different non-genetics-related reasons. We discuss the implications of our analysis for how multiple symbol systems should be presented in textbooks, and how they should be introduced in the classroom.
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(2017) Science & Education. 26, 10, p. 1143-1160 Abstract
Previous studies have shown that students often ignore molecular mechanisms when describing genetic phenomena. Specifically, students tend to directly link genes to their encoded traits, ignoring the role of proteins as mediators in this process. We tested the ability of 10th grade students to connect genes to traits through proteins, using concept maps and reasoning questions. The context of this study was a computational learning environment developed specifically to foster this ability. This environment presents proteins as the mechanism-mediating genetic phenomena. We found that students' ability to connect genes, proteins, and traits, or to reason using this connection, was initially poor. However, significant improvement was obtained when using the learning environment. Our results suggest that visual representations of proteins' functions in the context of a specific trait contributed to this improvement. One significant aspect of these results is the indication that 10th graders are capable of accurately describing genetic phenomena and their underlying mechanisms, a task that has been shown to raise difficulties, even in higher grades of high school.
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(2016) Developmental Cell. 36, 4, p. 401-414 Abstract
Patterning by morphogen gradients relies on the capacity to generate reproducible distribution profiles. Morphogen spread depends on kinetic parameters, including diffusion and degradation rates, which vary between embryos, raising the question of how variability is controlled. We examined this in the context of Toll-dependent dorsoventral (DV) patterning of the Drosophila embryo. We find that low embryo-to-embryo variability in DV patterning relies on wntD, a Toll-target gene expressed initially at the posterior pole. WntD protein is secreted and disperses in the extracellular milieu, associates with its receptor Frizzled4, and inhibits the Toll pathway by blocking the Toll extracellular domain. Mathematical modeling predicts that WntD accumulates until the Toll gradient narrows to its desired spread, and we support this feedback experimentally. This circuit exemplifies a broadly applicable induction-contraction mechanism, which reduces patterning variability through a restricted morphogen-dependent expression of a secreted diffusible inhibitor.
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(2013) Trends in Genetics. 29, 6, p. 339-347 Abstract
Morphogen gradients are used to pattern a field of cells according to variations in the concentration of a signaling molecule. Typically, the morphogen emanates from a confined group of cells. During early embryogenesis, however, the ability to define a restricted source for morphogen production is limited. Thus, various early patterning systems rely on a broadly expressed morphogen that generates an activation gradient within its expression domain. Computational and experimental work has shed light on how a sharp and robust gradient can be established under those situations, leading to a mechanism termed 'morphogen shuttling'. This mechanism relies on an extracellular shuttling molecule that forms an inert, highly diffusible complex with the morphogen. Morphogen release from the complex following cleavage of the shuttling molecule by an extracellular protease leads to the accumulation of free ligand at the center of its expression domain and a graded activation of the developmental pathway that decreases significantly even within the morphogen-expression domain.
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(2012) Cell. 150, 5, p. 1016-1028 Abstract
Morphogen gradients pattern tissues and organs during development. When morphogen production is spatially restricted, diffusion and degradation are sufficient to generate sharp concentration gradients. It is less clear how sharp gradients can arise within the source of a broadly expressed morphogen. A recent solution relies on localized production of an inhibitor outside the domain of morphogen production, which effectively redistributes (shuttles) and concentrates the morphogen within its expression domain. Here, we study how a sharp gradient is established without a localized inhibitor, focusing on early dorsoventral patterning of the Drosophila embryo, where an active ligand and its inhibitor are concomitantly generated in a broad ventral domain. Using theory and experiments, we show that a sharp Toll activation gradient is produced through "self-organized shuttling," which dynamically relocalizes inhibitor production to lateral regions, followed by inhibitor-dependent ventral shuttling of the activating ligand Spätzle. Shuttling may represent a general paradigm for patterning early embryos. PaperFlick: