Research into practice: Visualising the molecular world using a cognitive learning model

My early experience with students, confirmed by the chemical education literature, indicated student misconceptions and difficulties in chemistry stem from an inability to visualize the invisible molecular world. To address this challenge I developed an integrated suite of molecular-level animations in our VisChem project in the mid-90s. However, I quickly realised that you cannot change a student’s mental model at this level by simply showing animations that portray our expert models of this world, and then just expect novices to adopt them for understanding chemistry concepts. This started my journey to develop and evaluate learning designs (Tasker & Dalton, 2006) to enable students to engage with and learn from multimedia resources, based on an information-processing model consistent with the latest research in cognitive science. The most successful learning design is demonstrated here – http://www.youtube.com/watch?v=l7Hrj0hiWS8. REFERENCES Tasker, R., & Dalton, R. (2006). Research into Practice: Visualisation of the Molecular World Using Animations. Chemistry Education Research and Practice, 7(2), 141 - 159. Retrieved August 31, 2013, http://www.rsc.org/images/Tasker-Dalton%20paper%20final_tcm18-52113.pdf

The challenge of visualising science: Some research findings

We know that many misconceptions in science stem from an inability to relate its abstractions – mathematical relationships, concepts, and symbolism – to accurate, meaningful, mental models of invisible phenomena. We also know that you cannot create or change a student’s model simply by showing them a scientifically acceptable one, particularly if it conflicts with their own. In this presentation we will critically analyse the strengths and weaknesses of a number of visualisations from a range of scientific disciplines. Then we will use an evidence-based cognitive model for how we learn from audiovisual information, to inform best practice in using visualisation for teaching science. This will be illustrated with an example from our own research on the effectiveness of animations to assist students to build mental models of chemical substances and reactions

Can one version of online learning materials benefit all students?

Computers have had a significant impact on teaching and learning in recent years. When used as cognitive tools, computers can enable students to develop higher levels of cognitive processing by displaying information as both text and graphics to facilitate retention and transfer (Kozma 1987). For many students, chemistry is a subject that involves a novel set of terminology and symbology, and an array of abstract concepts and mental images not consistent with their observations and experiences of the world (Rusay 2003). Information and communications technology (ICT) offers the opportunity to help students develop understanding of these abstract concepts by illustrating them with multimedia simulations, thereby making them more concrete. ICT instruction can be reviewed multiple times, allowing the learner to control the pace of learning (Tissue, Earp and Yip 1996). Furthermore, students can access online pre-laboratory work at any time thereby allowing them flexibility whilst offering the university a cost effective means of delivery

VisChem: Building mental models of the molecular world using interactive multimedia

Understanding chemistry involves being able to link what one sees substances doing in the laboratory, to what one imagines is happening within these substances at the invisible molecular level. Only then can these ideas be communicated using abstract symbolism (e.g. chemical formulas), terminology and mathematics. The VisChem multimedia resources (QuickTime animations and video) explicitly link these three levels – the molecular, laboratory and symbolic. Research in chemical education over the last 20 years has revealed that many students have unacceptable, incomplete or non-existent mental models of chemical substances and processes at the molecular level. This problem is considered a major cause of misconceptions in chemistry, and is one reason why many students do not engage with the subject. In this poster session we will demonstrate some of the VisChem molecular-level animations (see http://vischem.cadre.com.au/). However, multimedia resources that promote meaningful learning should require ‘cognitive struggle’, facilitated through engagement, rather than by passive reception. We will describe how the animations are presented in live teaching contexts, and incorporated into interactive multimedia resources, to build mental models of the molecular world through meaningful ‘cognitive struggle’

Research into practice: Using molecular representations as a learning strategy in chemistry

Research in chemical education over the last 20 years has revealed that many students have unacceptable, incomplete or non-existent mental models of chemical substances and processes at the molecular level. Multimedia resources produced in the VisChem project (see http://vischem.cadre.com.au/) have been designed to address this problem. This paper investigates the effectiveness of VisChem molecular-level animations in enhancing student’ images of substances and processes in first year university chemistry. The effectiveness of these animations, and the way they were presented, were evaluated using a pre- and post-test format, with follow-up interviews of selected students. The pre- and post-test showed the sophistication and scientific acceptability of students’ images of molecular and ionic substances, before and after instruction. A comparison of pre- and post-data reveals significant improvements in students’ mental models of these chemical phenomena. In addition to this, data on self-perceptions of students’ confidence in their responses, and the vividness of their images, reveal a significant increase in both aspects following instruction. Interviews were used to probe what students believed to be the main sources of any changes in imagery or confidence. Without prompting, the molecular-level animations were commonly identified as a contributing factor

The influence of student engagement with online pre laboratory work modules on academic performance in first year chemistry

Information and communications technologies are increasingly being incorporated into teaching activities in higher education. They offer the opportunity to improve student learning experiences provided they are used in an educationally sound way. This may be through triggering student interest, improving engagement and, in turn, helping students to develop a deeper understanding of particular concepts. A previous study examined students’ engagement with two specific online prelaboratory work modules to determine how students engage with them, and correlate this engagement with learning style (Tasker, Miller, Kemmett and Bedgood Jnr 2003). The present study extends that work with a broader range of students and on a much larger scale, to investigate the claim that student engagement with these modules improves academic performance in first year chemistry

A Toomre-like stability criterion for the clumpy and turbulent interstellar medium

We explore the gravitational instability of clumpy and turbulent gas discs, taking into account the Larson-type scaling laws observed in giant molecular clouds (GMCs) and HI, as well as more general scaling relations. This degree of freedom is of special interest in view of the coming high-z ISM surveys, and is thus potentially important for understanding the dynamical effects of turbulence at all epochs of galaxy evolution. Our analysis shows that turbulence has a deep impact on the gravitational instability of the disc. It excites a rich variety of stability regimes, several of which have no classical counterpart. Among other diagnostics, we provide two useful tools for observers and simulators: (1) the stability map of turbulence, which illustrates our stability scenario and relates it to the phenomenology of interstellar turbulence: GMC/HI observations, simulations and models; (2) a Toomre-like stability criterion, $Q\geq\bar{Q}$, which applies to a large class of clumpy/turbulent discs. We make specific predictions about GMC and cold-HI turbulence, and point out the implications of our analysis for high-z galaxy surveys.Comment: MNRAS, in press. Moderate revision to match the accepted versio

Pathways to fatherhood: psychological well-being among Israeli gay fathers through surrogacy, gay fathers through previous heterosexual relationships, and heterosexual fathers

This study explored differences in psychological well-being as assessed by life satisfaction, parenthood satisfaction, depressive symptoms and the Big Five personality dimensions among 219 Israeli fathers; 76 gay men who had become fathers through a heterosexual relationship, 63 gay men who had become fathers through surrogacy, and 78 heterosexual men. After controlling for sociodemographic characteristics, gay fathers through surrogacy reported greater satisfaction with parenthood, greater satisfaction with their lives, and reported higher levels of extraversion when compared to heterosexual fathers. No significant differences emerged between the three groups on depressive symptoms, neuroticism, conscientiousness, agreeableness, and openness to experience. These findings emphasize the predominant similarities and some possible differences on psychological well-being between the different paths to fatherhood. This study is one of the first to compare several paths to fatherhood on psychological well-being, thus illuminating the contribution of fatherhood route to psychological well-being in an era where gay men are increasingly becoming fathers in diverse ways

Feedback or feedforward: Supporting students with alternate or missing conceptions in chemistry as they transition into tertiary chemistry

Constructivist learning environments are most effective when the learner and teacher are both aware of the existing conceptual models that learners possess to enable them to extend and apply their understanding rather than resort to rote learning (Taber, 2001). As students transition into, and engage in, the new tertiary learning environment it is important to assist them to maximise the effectiveness of their learning which requires measurement or diagnosis of their existing conceptual understanding. One of the challenges in teaching chemistry is to encourage students to recognise their existing knowledge and conceptual understanding and then apply it in new learning situations (Schraw, Crippen, & Hartley, 2006). Feedback is particularly important for first-year students because they are coming to terms with the change of environment, expectations, teaching approaches and forms of assessment. In this context, Hattie and Timperley’s three questions (Hattie & Timerley, 2007) are particularly relevant: “Where am I going?”, “How am I going?” and “Where to next?” Formative assessment is critical to “How am I going?” and the feedback is just as valuable for the instructor as for the students to support student learning. REFERENCES Hattie, J., & Timperley, H. (2007). The Power of Feedback. Review of Educational Research. 77, 81-112. Schraw, G., Crippen, K. J., & Hartley, K. (2006). Promoting self-regulation in science education: Metacognition as part of a broader persepective on learning. Research in Science Education. 36, 111-39. Taber, K. S. (2001). The mismatch between assumed prior knowledge and the Learner’s conceptions: A typology of learning impediments. Educational Studies, 27, 159-71

Haloes gone MAD: The Halo-Finder Comparison Project

[abridged] We present a detailed comparison of fundamental dark matter halo properties retrieved by a substantial number of different halo finders. These codes span a wide range of techniques including friends-of-friends (FOF), spherical-overdensity (SO) and phase-space based algorithms. We further introduce a robust (and publicly available) suite of test scenarios that allows halo finder developers to compare the performance of their codes against those presented here. This set includes mock haloes containing various levels and distributions of substructure at a range of resolutions as well as a cosmological simulation of the large-scale structure of the universe. All the halo finding codes tested could successfully recover the spatial location of our mock haloes. They further returned lists of particles (potentially) belonging to the object that led to coinciding values for the maximum of the circular velocity profile and the radius where it is reached. All the finders based in configuration space struggled to recover substructure that was located close to the centre of the host halo and the radial dependence of the mass recovered varies from finder to finder. Those finders based in phase space could resolve central substructure although they found difficulties in accurately recovering its properties. Via a resolution study we found that most of the finders could not reliably recover substructure containing fewer than 30-40 particles. However, also here the phase space finders excelled by resolving substructure down to 10-20 particles. By comparing the halo finders using a high resolution cosmological volume we found that they agree remarkably well on fundamental properties of astrophysical significance (e.g. mass, position, velocity, and peak of the rotation curve).Comment: 27 interesting pages, 20 beautiful figures, and 4 informative tables accepted for publication in MNRAS. The high-resolution version of the paper as well as all the test cases and analysis can be found at the web site http://popia.ft.uam.es/HaloesGoingMA