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Challenges in Creating Online Exercises and Exams in Organic Chemistry

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Challenges in Creating Online Exercises and Exams in Organic Chemistry 48 CHIMIA 2018, 72, No. 1/2 ChemiCal eduCation doi:10.2533/chimia.2018.48 Chimia 72 (2018) 48–54 © Swiss Chemical Society Challenges in Creating Online Exercises and Exams in Organic Chemistry Bernhard Jaun and Carlo Thilgen* Abstract: e-Learning has become increasingly important in chemical education and online exams can be an at- tractive alternative to traditional exams written on paper, particularly in classes with a large number of students. Ten years ago, we began to set up an e-course complementing our lecture courses Organic Chemistry I and II within the open-source e-learning environment Moodle. In this article, we retrace a number of decisions we took over time, thereby illustrating the challenges one faces when creating online exercises and exams in (organic) chemistry. Special emphasis is put on the development of MOSFECCS (MOlecular Structural Formula Editor and Calculator of Canonical SMILES), our new editor for drawing structural formulae and converting them to alphanumeric SMILES codes that can be submitted as answers to e-problems. Convinced that the possibility for structure input is essential to set up sensible chemistry quizzes and exams, and realising that existing tools present major flaws in an educational context, we decided to embark on the implementation of MOSFECCS which takes into account a number of didactic aspects. Keywords: e-Learning · Moodle · Online exercises and exams · SMILES generator · Structural formula editor and its application to problems relevant fullerenes and fullerene derivatives. in biology. He is a recipient of the Silver More recently, his interest has focused Medal of ETH Zurich and the Werner on the generation of nanostructured Prize of the Swiss Chemical Society. surfaces by assembly of porous molecular He taught courses in 1st year organic networks, the ordering of which is based chemistry (1991–2012) for students of on supramolecular synthons. Carlo Biology, Pharmaceutical Sciences and Thilgen taught an advanced course in Health Sciences and Technology, as well Supramolecular Chemistry next to basic as advanced NMR and advanced physical Organic Chemistry courses for students in organicchemistryforstudentsinChemistry Chemistry and Interdisciplinary Natural and Interdisciplanary Natural Sciences. Sciences. Currently, he is teaching first- Bernhard Jaun is honorary professor year Organic Chemistry for students in (emeritus) in the Laboratory of Organic Biology, Pharmaceutical Sciences and Chemistry, ETH Zürich. After studies Health Sciences and Technology. In in chemistry at ETH Lausanne and ETH addition, he directs basic and advanced Zurich, Bernhard Jaun obtained his practical Organic Chemistry courses for PhD from ETH Zurich working under students in Biology and Pharmaceutical the supervision of A. Eschenmoser and Sciences. J.F.M Oth. After a two-year stay as a postdoctoral fellow in R. Breslow’s group at Columbia University, New York, he 1. Strengthening a Basic Organic returned to ETH Zurich where he started Chemistry Course by Online his own research group in 1989. He was Exercises: Initiation of Our Project head of the NMR-facility of the laboratory for organic chemistry from 1983 to 2013. In a basic one-year organic chemistry Bernhard Jaun’s research focus was in Carlo Thilgen received his diploma course at the university, the students are the area of physical organic chemistry degree in Chemistry and his PhD degree expected to: from the Rheinische Friedrich-Wilhelms- • learn a new ‘language’ (proper termi- Universität Bonn, working under the nology) and a new ‘script’ (structural supervision of Fritz Vögtle. After a formulae) to describe the structure and postdoctoral stay in the group of François behaviour of molecules; Diederich at the University of California, • train their perception of 3D molecular Los Angeles, he moved with this group structure and deduce it from 2D struc- to ETH Zurich, where he became Senior tural formulae; interconvert various 2D Assistant, Lecturer and, in 2011, Adjunct representations of 3D structures (per- *Correspondence: Prof. Dr. C. Thilgen Professor (Titularprofessor). He carried spective drawings, Natta-, sawhorse-, Laboratorium für Organische Chemie out research in the fields of molecular Newman, Fischer projections); ETH Zurich recognition and fullerenes, in particular the • apply rules and conventions, e.g. sys- Vladimir-Prelog-Weg 3 CH-8093 Zurich isolation and the chemistry of new higher tematic nomenclature, stereodescrip- E-mail: [email protected] fullerenes as well as the chirality of pristine tors, or Fischer projections; ChemiCal eduCation CHIMIA 2018, 72, No. 1/2 49 • carry out a qualitative conformational any time. Last but not least, we had the idea 2. A Major Flaw of Most e-Learn- analysis of basic systems, e.g. cyclo- at the back of our mind to eventually ex- ing Environments: The Missing hexane; tend the project toward the elaboration of Possibility for Molecular Structure • describe the electronic delocalization online exams. With about 500 candidates Input in π-systems by use of resonance struc- per year, computer exams appear as an ap- tures; pealing alternative to the traditional manu- As nicely illustrated by Fig. 1, chemis- • recognize typical structural sub-units ally corrected exams written on paper. try – and organic chemistry in particular – (functional groups) which confer dis- The project was initiated in the fall is a very ‘visual’ science. To convey the tinctive physical or chemical (acidity, semester 2007 by one of us (B. J.) with a essential information about a molecular reactivity) properties to molecules; relatively small set of online exercises em- structure, chemists use structural formu- • familiarize themselves with a number bedded within the e-learning environment lae, i.e. two-dimensional drawings that are of basic organic reactions and apply Moodle. In 2008, a FILEP grant (‘Fonds combinations of graphs, letters, numbers them to synthetic problems. zur Finanzierung lehrbezogener Projekte’) and other symbols, possibly including de- Whereas the necessary concepts and from the rector of the ETH Zurich allowed tails on the 3D-arrangement of atoms (ste- theoretical background to achieve these a nine-month dedicated full-time employ- reo-information). goals are usually imparted in a lecture (2–4 ment of a chemist, thereby considerably in- Because structural formulae and re- h per week) or can be learnt from textbooks, creasing the number and quality of the quiz- action schemes are so essential in organic the acquirement and mastering of the men- zes (for an example, see Fig. 5). In 2012, the chemistry, students must practice this no- tioned skills is a matter of practice. At the class was taken over by C. T. who started to tation or ‘script’ from the very beginning. Department of Chemistry and Applied build a pool of synthesis problems for the Any reasonable system for online exercises Biosciences of the ETH Zurich, this is tra- 2nd semester, in which fragmentary reaction must, therefore, accept structural formulae ditionally done in a weekly problem-solv- schemes have to be completed with prod- in the formulation of questions as well as the ing session (1–2 h), in which small groups ucts, reactants or reaction conditions. At the input of answers. Regarding the former re- of students coached by a more advanced same time, we started to convert old ‘paper quirement, the ‘quiz’ modules of most cur- fellow discuss the solutions of assignments exams’ to online problems in order to test rent e-learning environments allow the use distributed beforehand as homework. the suitability of various types of questions of graphic elements as part of the question. However, increasing student numbers in view of an online assessment. With the By contrast, it is a real challenge to provide and the policy to group students from gained experience and free infrastructure a tool that allows students to draw struc- different study programs for introductory capacities for a large online exam having tural formulae as answers and have these courses in basic science, taught as subsidi- finally become available, we are now all set checked by the computer for correctness. In ary subjects, has led to huge classes of up to for the Winter 2018 session. our view, such a graphical input tool is key 500 students. This has made it increasingly The first version of the open-source for didactic reasons, as it makes a huge dif- difficult to maintain a culture of discussion e-learning management software Moodle ference as to whether students actively try and dialogue in the exercise groups where was released in 2002[1,2] and a distribution to draw the correct structure themselves or attendance has reached a level of about 25 has been available at the ETH Zurich for simply choose one out of a given set (multi- students. about ten years. Accordingly, many people ple choice). Unfortunately, most e-learning Furthermore, we feel that first-year are familiar with the system and the pos- environments allow only multiple-choice students, who come from different schools sibilities it offers. Rather than providing type answers or the input of text or numbers with different core subjects, who have cho- a tour d’horizon of our course, we there- (alphanumeric strings) which are easily and sen different major subjects at the univer- fore decided to focus on our strategy to reliably checked for correctness. sity and head toward a variety of special- overcome a very serious limitation of the In contrast to human beings, however, izations, have extremely different back- text-based Moodle system when it comes software is quite inept at deciding whether grounds and interests and, consequently, to chemistry, i.e. the missing possibility for two drawings correspond to the same struc- need different extents of training to be a graphical input of molecular structure, an ture or not.[3] The conventions for struc- enabled to pass a uniform exam at the end essential aspect in the context of organic tural formulae are rather loose and allow of the first year.
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