Teaching and Learning Portfolio

Educators have long agreed that the ̳nature of science‘ (NOS) is an important aspect ofany science curriculum. However, exactly how to incorporate NOS into science curriculumremains contentious. We developed a new science course for non-science majors that used anexplicit-reflective approach, where NOS is purposefully combined with the process of scientificinquiry (SI) and opportunities for student reflection are provided. Here, we focus on instructionalmaterials from the 3-week capstone module – global climate change – to assess the utility ofNOS from three different perspectives. We assessed whether (1) a chronological approach inlectures improved understanding of NOS, SI, and scientific content (2) a reflective NOS activityin labs improved understanding of SI, and (3) students showed learning gains in a) scientificcontent, b) scientific inquiry, and c) scientific skills. Students reported that the chronologicalapproach in lecture improved their understanding of NOS (65%), SI (69%), and global warmingcontent (87%). Results from formative assessment showed that students performed significantlybetter on SI when a reflective NOS activity occurred in labs (Wilcoxon Signed Ranks Test, p-value <0.01). Multivariate analysis of learning gains showed that after explicit-reflectiveinstruction, significant gains were made in scientific content (MRPP, p-value <0.001) andscientific inquiry (MRPP, p-value <0.001), but not scientific skills. IntroductionWe developed a course for nonscience majors (Ways of Knowing Science) to improvestudent understanding of science, affect student attitudes about science, and build studentscientific literacy. In order to achieve scientific literacy, researchers suggest students must graspmore than just scientific facts, but the relationships and connectedness between science,technology, and society (Abd-El-Khalick and BouJaoude 1997). Teaching the ̳nature of science‘(NOS), or the social and technological context in which science takes place, is an important steptowards science literacy, however there is no consensus on exactly how to incorporate NOS inscience curricula. Ways of Knowing in Science uses an ̳explicit-reflective‘ approach whichexplicitly combines nature of science, process of scientific inquiry, and reflection in instructionalmaterials (e.g., Khishfe and Abd-El-Khalick 2002). This teaching approach exposes students tomore than just scientific facts – but also important societal influences on science and thediversity of ways in which each discipline conducts scientific inquiry (Fig. 1). We propose thatthis approach to teaching a general science course gives students greater insight into therelevance of scientific concepts; greater acceptance of science as a process of human inquiryrather than a set of accepted truths; and more opportunities to practice scientific habits of mind.Ways of Knowing in Science explores scientific inquiry through paradigm shifts (Kuhn1962) in five different scientific fields: heliocentrism, plate tectonics, radioactivity, evolution,and global climate change. Here we focus on instructional materials developed for the 3-weekcapstone module, global climate change. Our research explores the utility of NOS from threedifferent directions. First, we consider a specific approach to weaving NOS and SI intoinstructional materials – chronological. Although there is no conclusive evidence that simplyteaching science in a historical framework improves student understanding of NOS (Khishfe and Abd-El-Khalick 2002), we hypothesized that approaching an explicit-reflective curriculumthrough a strictly chronological lens would improve student understanding of NOS. Second, wefocused on the reflective component of our pedagogical approach. We asked whether including areflective NOS activity in lab improves understanding of science inquiry (SI). Finally, weassessed the overall impact of the module, with its explicit-reflective approach, in terms ofstudent learning gains. The global climate change module lasted for three weeks, with six lectures and three labs.Lectures were a combination of discussions, demonstrations, hands-on activities, and powerpointlectures. The powerpoint lectures provided the backbone of instruction. Here we used thechronological approach to show how NOS and SI are woven together in climate change science,following the timeline shown in Weart‘s (2003) The Discovery of Global Warming. Theinteraction between science, society, technology, and politics was set against a backdrop of thesteady increase in CO2 concentration as scientists work for more than a century to answer justone question – ―How much will Earth‘s temperature rise with doubled atmospheric CO2?‖. Wetaught about several important SI milestones in understanding our climate system, particularlycarbon dioxides‘s relationship with temperature and the cause of ice ages. SI milestonesrepresent nearly every way of knowing used in the sciences: observation, calculation, naturalarchives, experiments, and simulation models. Additionally, we highlighted how NOSmilestones clearly move climate change science in new directions (Fig. 2). For example, WWIIsteered massive funding toward climate science research, much of which forms the basis for ourunderstanding of global warming. In labs, we focused on a diverse array of learning and teaching styles to give student‘sexperience in scientific skills and SI. In the scientific skills lab, students worked in groups tobecome expert on a single graph from the latest summary report from the IntergovernmentalPanel on Climate Change (IPCC) and then presented the graph to the class, including the graph‘simplications. In one of the SI labs, students tested different hypotheses about the climate systemwith a computer simulation model, where they could see the result of each manipulation. Herethey experienced simulation as a new way of knowing. In the other SI lab, we focused onuncertainty in science by running several statistical analyses on a local dataset related to globalwarming. To assess the utility of a reflective NOS activity on student understanding of SI, weadded a reflective NOS treatment to this lab. Although this lab was mathematically challenging,students were able to relay their reflect on their understanding of uncertainty by writing a letterto the editor about uncertainty in climate change science. Fig. 2. Nature of science milestones shown against atmospheric CO2 concentrations. MethodsChronological approach in lecturesAt the end of the semester, we administered an online survey, the Student Assessment ofLearning Gains (SALG), to assess what students thought about the chronological approach inlectures. We incorporated four questions about our chronological framework into the survey andanalyzed the percentage of students who responded in a particular way. The SALG questionswere as follows:1) The climate change module is distinct from the other modules. Select which aspect you feelhelped you the most with understanding this module:a) chronological approachb) multiple variablesc) multiple ways of knowing including simulationd) relevant implications for your life2) Do you feel the chronological approach taken in the Climate Change module helped you betterunderstand "Nature of Science"?3) Do you feel the chronological approach taken in the Climate Change module helped you betterunderstand "Scientific Inquiry"?4) Do you feel the chronological approach taken in the Climate Change module helped you betterunderstand the content behind the theory of anthropogenic global warming? Reflective NOS activity in labsTwo of the three labs in the global climate change module were focused on SI, (1)Uncertainty and Statistics and (2) Simulation as a Way of Knowing. After the Uncertainty andStatistics Lab, students were given the following assignment as a reflective NOS treatment (Fig3). At the end of the module, we assessed student understanding of SI with two essay-basedformative exam questions: one on uncertainty, the other on simulation. We used a WilcoxonSigned Ranks Test in SYSTAT 11 (SYSTAT Software, Inc. San Jose, USA) to assess whetherstudents performed significantly better on the uncertainty question. Fig. 3. Reflective NOS assignment given to students after the Uncertainty and Statistics lab. Learning gains after the whole moduleBefore and after this module, we implemented a short-answer pre-post test focused onthree topics: nature of science, science inquiry, science content, and science skills. We convertedstudent responses into a multivariate presence/absence table which summarized each major ideaa student described for each question. We used Multiple Response Permutation Procedures(MRPP, McCune and Grace 2000), essentially a non-parametric MANOVA, to assess whetherpretest responses differed significantly from posttest responses. MRPP provides an A statistic,which can be interpreted as strength of effect. A larger A statistic denotes stronger difference andas such provides a relative measure of learning gains. We employed Indicator Species Analysis(using 1000 randomizations in the Monte Carlo test of significance) to identify the largestcontributory factor to increased learning. In each case we used a Jaccard‘s distance to depict̳community‘ resemblances and PC-ORD 4.0 (MjM Software Designs, Gleneden Beach, USA) torun analyses. We report learning gains for science inquiry, science content, and science skills.We did not report learning gains for nature of science because we were unable to convert studentdescriptions of their understanding of NOS into a presence/absence table. ResultsSALG results show that overall, well more than half of all students felt the chronologicalapproach helped them better understand NOS, SI, and science content (Fig. 4). A very highpercentage of students felt the chronological approach helped them better understand the contentbehind the anthropogenic global warming theory. However, it was clear that students did notconsider the chronological approach to be the biggest difference between this module and others.They felt that the ̳relevance to their life‘ was higher in this module than in others (Table 1).Students performed significantly better on the uncertainty question, which was associated with a reflective NOS activity, than on the simulation question (Wilcoxon Signed Ranks Test, p =0.008). After this module, students showed learning gains across all three topics, but not for allquestions (Table 2). Science inquiry and content questions show stronger learning gainscompared to science skills. In Question 1) on the pre-post test, learning gains were due tostudents adding the term ―uncertainty‖, the subject of a reflective NOS activity, to their answer.In Question 2) multiple factors changed in terms of student understanding of the greenhouseeffect. In Question 3) learning gains were slight. Did the chronological approach help?