DOI:http://dx.doi.org/10.22201/fq.18708404e.2020.5.76857

Covid-19 school disruptions as drivers of curriculum change in the forensic science organic chemistry laboratory

Luis Jiro Suzuri Hernández,[a] Laura Alicia Espinosa Escobar,[a] Ana María Sosa Reyes,[a] Jorge Luis López Zepeda[a] y Luis Alexa Villavicencio Queijeiro[a]

Introduction

Chemistry is a crucial tool for many forensic investigations, since the analysis of physical evidence from a crime scene often involves identifying unobservable substances or materials, separating them from support matrices and/or contaminants, and measuring their amounts. Pills, powders, plant matter, blood, urine, tissue, hair, fire debris and accelerants, gunshot residues, bullet lead, propellants and explosive mixtures, pre- and post-blast samples and residues, soil, glass, paints and inks, fibers, plastics, and paper are the most common objects, substances and materials submitted for chemical analysis in the course of everyday forensic casework (Bell, 2009). Reliance on chemical expertise to answer questions related to the administration of justice can be traced back to the first half of the 19th century, when the Spanish chemist and toxicology pioneer M. J. B. Orfila (1787-1853) testified for the prosecution in the trial of Marie LaFarge, having discovered arsenic in her husband’s exhumed body (Bell, 2014, p. 9). The application of chemistry to poisoning cases ranks as one of the first applications of modern science to judicial matters. Today, like never before, forensic science has become an interdisciplinary endeavor that brings together a wide range of disciplines—from the physical to the social sciences—to assist in establishing the facts of a case. In spite of this diversity of expertise, which speaks to the complexity of forensic problems, chemistry remains one of the cornerstones of forensic teaching and practice: in a review of 78 forensic science courses offered worldwide by higher education institutions, Samarji found that almost 23 per cent of them—the highest proportion of all—were administered by Chemistry Departments, surpassing the number of offerings from other departments, such as those of Biology and Criminal Justice (Samarji, 2012).

In 2013, in response to Mexico’s decades-long crisis of its criminal justice system—besieged by drug trafficking organizations and facing mounting complaints of military and police abuse and torture, enforced disappearances, and extrajudicial killings (Lee, Renwick and Cara Labrador, 2020) —the National Autonomous University of Mexico (UNAM) created the country’s first undergraduate program in Forensic Science. Its chief aim is to train forensic scientists capable of aiding both the police in the investigation of allegedly criminal acts and in the processing of crime scenes, and prosecutors or defense attorneys in case preparation (Facultad de Medicina, 2013, pp. 2-7, 19, 37-45). To this end, the curriculum includes subjects from eight core disciplinary areas: physics, chemistry, biology, medicine, psychology, criminalistics, research methods, and the law, with a strong emphasis on the development of research skills (Forensic Science Undergraduate Programme in a Nutshell, 2015). Students in the program are not meant to train to perform chemistry laboratory work, as an aspiring analytical chemist would be. From the earliest stages of the program’s creation, UNAM’s School of Chemistry—fully aware of the importance of the discipline for forensic investigations—actively participated in the design of the curriculum, which in its actual form comprises three foundational courses—General Chemistry, Organic Chemistry (OC), and Biochemistry—and three specialized ones—Forensic Chemistry, Toxicology, and Hematology and Serology. All courses require students to perform a sizeable amount of hands-on laboratory work. Not surprisingly, given that forensic scientists are a recent addition to Mexico’s higher education landscape, the curricula of the foundational courses share significant similarities to those of the same courses taught in the School of Chemistry— its design most certainly influenced by the knowledge and skills chemistry teachers believe will prepare professional chemists to meet the demands of the workplace.

Even before COVID-19 began spreading, forcing the closure of universities and the shift to distance learning, the chemistry instructors in the Forensic Science Undergraduate Program (FSUP) were engaged in discussions about how to better align their curriculum with the professional skill set expected of forensic scientists in Mexico, which is not the same of that of forensic chemists. Apart from the challenge of teaching chemistry for non-chemists, limited teaching time is one of the main obstacles faced by instructors: students enrolled in the program receive only one-fourth of the instruction in OC that a peer would receive in the School of Chemistry (i.e., only one semester versus four). Compounding the issue, as is the case in most public education institutions in Mexico, resources tend to be scarce, making laboratories a significant financial investment for higher education institutions—a concern that has been highlighted recently, and with renewed interest, due to the pandemic (Bretz, 2019; Arnaud, 2020). In summary, there is a pressing need to target chemical education to the specific training needs of forensic scientists while making more efficient use of the time and resources available for laboratory instruction.

By mid-March, unable to continue as planned, the half-completed OC course in the FSUP had to be abruptly redesigned for online learning. Laboratory sessions were cancelled and replaced by tasks such as readings followed by quizzes, synchronous videoconferences, and problem sets with IR/NMR spectra. Assigning at-home laboratory activities was considered at one point, but the short timeframe of the shift to distance learning meant that many students would be unprepared—in terms of materials and equipment—to carry out laboratory experiences in their homes, and neither could they freely go out to purchase them without risking their health. Likewise, the two OC instructors were wary of asking students to incur any additional expenses at a time of economic uncertainty. In this context, instructors began thinking not only of how to successfully conclude the term, but also what changes could be implemented in the future to adapt the course to fully online or blended learning.

Methods

To aid the current OC instructors in the FSUP in their efforts to systematically 1) identify the important features of laboratory activities with the aim of adapting them to distance learning and 2) assess the suitability of the curriculum for the training of forensic scientists, both were interviewed to elicit their views of their laboratory teaching. From the interviews, insights were extracted towards developing a viable and flexible—but no less rigorous—hybrid and/or online chemistry curriculum tailored for forensic scientists that, apart from hands-on laboratory experiences, could include interactive simulations, videos, animations, data sets, or at-home laboratory activities (Casanova, 2006). Questions were limited to the three laboratory activities completed before shutdown: a) “Intermolecular Forces and the Solubility of Substances”; b) “Reactivity of Alcohols”, and c) “Acid-base Extraction of Organic Compounds”. By choosing these activities, we were assured that both instructors had first-hand experience of guiding students through them. Interviews were conducted separately and recorded using a video conferencing tool.

To structure the interviews, three assessment instruments—designed to explore features of laboratory experiences from different perspectives—were chosen: 1) the Practical Activity Analysis Inventory (PAAI) (Millar, 2009); 2) the Competency Rubric Bank for the Sciences (CRBS) (Kishbaugh, 2012); and 3) the Meaningful Learning in the Laboratory Instrument (MLLI) (Galloway, 2005). Both instructors completed the PAAI for each of the three laboratory activities, as per the developer’s instructions and without knowledge of the other’s responses. For the CRBS and the MLLI, both were asked to rate the work carried out in the OC laboratory against the criteria set out by each instrument, applying a four-point Likert-type scale to each criterion, i.e., 1 = strongly disagree; 2 = disagree; 3 = agree; and 4 = strongly agree.

The PAAI was chosen because it allows a thorough description of practical activities in general (of which laboratory work is only one kind) that can help to explore the effectiveness of activities in a systematic way, starting with the intended learning outcomes and ending with the extent to which students achieved them. The wide spectrum of competencies included in the CRBS, on the other hand, is especially relevant for forensic scientists, since their main tasks revolve around applying scientific research methods to the interdisciplinary study of criminal acts. Finally, the MLLI has a clearly articulated theoretical basis (Novak’s Theory of Meaningful Learning) that goes beyond what students do to focus on how they think and feel in the laboratory, under the assumption that actions are influenced by cognitive and affective domains.

Results and discussion

For the sake of brevity, and because our chief aims are to establish a common starting point from which to assess the suitability of the OC curriculum taught to forensic scientists-in-training and gain insights into which aspects of laboratory work can be effectively shifted to distance learning, we focus on those aspects that both instructors agreed upon. Having said that, the disparities in their views are substantial enough to merit a more thorough exploration. (Their complete responses can be found in the Supporting Information.) Regarding the results from the PAAI, only those features that both instructors selected for at least two of the three laboratory activities were considered as shared features of OC instruction. In the case of the CRBS and the MLLI, for any given criterion, if both instructors selected a Likert rating of 1 or 2, the criterion was regarded as not likely to be part of laboratory activities. On the contrary, if both selected a rating of 3 or 4, the criterion was deemed likely to be.

Features of the laboratory activities used to teach Organic Chemistry

Box 1 summarizes the main features of the hands-on activities used to teach OC in the FSUP. The tasks identified as common to laboratory instruction center on the development of procedural skills that, collectively, aid students in understanding how scientific research is conducted: data collection, analysis, and presentation; compliance with standardized procedures; observation and explanation of phenomena and their properties, and manipulation of variables. Briefings before laboratory sessions tended to focus primarily on the equipment and procedures to be used—a topic consistent with the tasks that students were expected to perform. In light of the need to shift instruction to distance learning while simultaneously improving its fit to the skill set expected of forensic scientists, these findings pose an interesting dilemma. Given the emphasis placed on producing forensic graduates with a strong background on research methods, it is clearly essential for students to gain experience in the tasks listed above. However, in Mexico’s criminal justice system, only certified chemists can legally carry out laboratory tests and present their conclusions in court. Forensic scientists might be called upon to request laboratory tests as part of a criminal investigation, but they will not be the ones performing them. This opens up the possibility of using non-laboratory-based teaching strategies (for example, Problem- or Project-Based Learning and case studies) to develop their background in research methods. Likewise, conceptual understanding of OC could be developed by simulations, analysis of data sets, or video recordings of demonstrations. Students could develop a satisfactory understanding of chemistry to request appropriate tests and explain their results to police, prosecutors, defense attorneys or judges without having enough expertise to perform the tests themselves. As important as technical skills might be for the training of chemists, their value for forensic scientists is secondary to an understanding of the principles that underlie the chemical behavior of substances and materials, and how they are applied to the analysis of samples.

Even though both instructors believed that understanding scientific ideas was a fairly important aim of the work carried out in the OC laboratory, JLLZ prioritized the development of knowledge about the natural world (i.e., recalling patterns in observations; understanding concepts, models, or theories), while AVQ gave precedence to students learning how to use the equipment and follow standard procedures. These divergent views could be attributed to the instructors’ number of years teaching OC courses (AVQ was in her first year as an OC instructor, whereas JLLZ has 17-years worth of experience teaching it) and their particular interpretations of the training needs of future forensic scientists. Although significant, in terms of the actual teaching in the OC laboratory, differing views about the aims to pursue are not particularly worrying, given the fact that the course is taught by two instructors, their viewpoints and experiences complementing one another.

Noteworthy among the skills where little to no agreement was reached, or were not even selected by the instructors, are those necessary for planning and conducting original research: identify good research questions; plan strategies for collecting data; design observation procedures; choose appropriate equipment; make or test predictions; explore how dependent variables change in relation to independent ones; discover patterns in data, and draw and assess conclusions. These omissions are consistent with the emphasis placed on technical proficiency. The omitted skills are notoriously hard to integrate into highly structured laboratory activities even though they are vital for forensic scientists; fortunately, they can be taught through activities compatible with distance learning.

Competencies exercised in the Organic Chemistry laboratory

Box 2 summarizes the key competencies that instructors agreed students had the opportunity to develop in the OC laboratory, as well as those they did not, according to the criteria set by the CRBS. The first group of competencies is made up of both practical skills—i.e., consider safety hazards and assess the accuracy and precision of data—and cognitive ones—organize ideas and express them orally—that are roughly consistent with the features the instructors agreed were common to at least two out of the three laboratory activities (see Box 1). Conversely, there is substantial overlap between the competencies in the second group—those not developed substantially—and the features in the PAAI that were not selected by both instructors—sometimes not even by one of them: for example, in the PAAI, only JLLZ believed that two of the laboratory activities could help students improve their understanding of scientific ideas, concepts, explanations, models, or theories. Moreover, in the instructors’ opinion the activities do not offer students the opportunity to identify research questions; plan strategies for collecting data; and draw conclusions—competencies that were also not associated with the activities when assessed against the CRBS. Finally, application of the CRBS revealed that laboratory work does not foster an understanding of aspects of the nature of science and its societal relevance. This last point is relevant because the apparent emphasis placed on developing technical proficiency in the OC laboratory is unlikely to lead by itself to such an understanding: for example, being proficient at making observations does not make students aware of the theory-ladenness of observations—explicit instruction is be needed for that (Schwartz, 2004). Critically thinking about research methods is enhanced by philosophical awareness of how science works, and it would certainly strengthen the ability of forensic scientists to assess the quality of theirs’ and others’ research. As is the case for the skills included in the PAAI, the unexercised competencies in Box 2 could be developed by students through a distance learning approach.

The OC laboratory in the FSUP could address the need to increase students’ exposure to more genuine and comprehensive research experiences by adopting, for instance, approaches like Cognitive Apprenticeship Theory as a tool to structure laboratory activities into a coherent whole that resembles actual scientific research (Stewart,2003).

Cognitive and affective domains addressed in the Organic Chemistry laboratory

The MLLI offers an alternative view of laboratory activities by focusing on their cognitive and affective domains. Box 3 shows that what students are most likely to think and feel in the laboratory relates to procedural aspects: the purpose of the procedures and the time available to perform them; the use of instruments, and the development of positive attitudes and work habits. On the other hand, what students are failing to experience in the laboratory extends to domains beyond mere technical expertise, consistent with the findings from the PAAI and the CRBS. DeKorver and Towns (2015) have already pointed out the lack of attention given to the affective domain in the laboratory (DeKorver, 2015), in spite of its influence on behavior and motivation. Particularly worrying, from the point of view of forensic science, is the lack of development of students’ critical thinking and problem-solving skills, crucial for planning and conducting research. As previously alluded to, forensic scientists are not being prepared to perform forensic chemists’ duties but, rather, to act as a liaison between scientific experts and justice operators. In this regard, understanding the underlying principles of chemical analysis is indispensable, especially when questions about the validity and reliability of results are relevant. Finding out that instructors believe students are unlikely to think about the behavior of molecules and relate it to observations—together with a lack of interest in the quality of data and in whether it makes sense—calls attention to the urgent need to reorient the curriculum—particularly that of OC—to areas better matched to the challenges forensic scientists are expected to face. Fortunately, these skills can also be taught remotely outside of laboratories. An inquiry-based approach could prove effective in promoting positive attitudes towards chemistry in the context of forensic science training (Sevian, 2012).

Conclusions

The COVID-19 pandemic has abruptly and dramatically changed teaching, and even if it proves to be a short-lived experience it is certain to leave long-lasting lessons. For courses with a sizeable laboratory component, the shift to distance learning is especially challenging, since materials and equipment become inaccessible. Such adverse conditions are forcing instructors to come to terms with the fact that developing some practical skills will not be possible until laboratory teaching is resumed. But they also offer the opportunity to reassess the value and role of the laboratory, particularly for programs where chemistry is taught as a subsidiary subject. Necessity turns into possibility.

In the FSUP taught at UNAM, chemistry subjects are meant to provide students with an understanding of the concepts and theoretical models that chemists use to plan, execute, and evaluate their research, with the ultimate aim of allowing forensic scientists to identify when chemical expertise is needed to investigate an allegedly criminal act. Such an understanding is also deemed essential for effective and accurate communication of the findings of a criminal investigation to other scientists, judicial operators, and lay persons. Any and all laboratory activities devised for the training of forensic scientists should deliberately aim at preparing them to fulfill their role as part of the criminal justice system. Attempting to improve the effectiveness of laboratory instruction and adapt it to distance learning can end up being an empty exercise if its aims are not carefully considered.

In 1970, Prosser (p. 19) asked his readers “whether the non-chemist students are receiving the type of guidance best suited to their interests and talents” (Prosser, 1970). This question is as valid and timely today as it was back then, and even more so when access to laboratories is restricted and inquiries are made about whether the high cost incurred by laboratory instruction is a worthwhile educational investment based on its effectiveness and its relevance for chemistry non-majors—as forensic scientists are (Hawkes, 2004).

Supplementary Fig. 1. PAAI. Complete responses of the two instructors to the Practical Activity Analysis Inventory assessment instrument. Both instructors completed the PAAI for each of the three laboratory activities (1, 2, 3 and 3B), as per the developer’s instructions and without knowledge of the other’s responses. Both were asked to rate the work carried out in the OC laboratory against the criteria set out by the instrument, deciding dichotomously whether a given criterion was met (signaled by a value of “1”) or not. Each instructor is represented by a color (red and blue) and on the criteria where there was agreement, a (✓) is placed next to the column.

Supplementary Fig. 2. CRBS. Complete responses of the two instructors to the Competency Rubric Bank for the Sciences assessment instrument. Both instructors were asked to rate the work carried out in the OC laboratory against the criteria set out by each instrument, applying a four-point Likert-type scale to each criterion, i.e., 1= strongly disagree; 2 = disagree; 3 = agree; and 4 = strongly agree. Each instructor is represented by a color (red and blue) and the criteria where there was agreement is identified by a (✓) next to the column; when there was no agreement, a (X) appears next to the column.

Supplementary Fig. 3. MLLI. Complete responses of the two instructors to the Meaningful Learning in the Laboratory Instrument (MLLI). Each instructor is represented by a color (red and blue). When both respondents chose 1 or 2, they were awarded LOW belief in the proposition (✓). When both respondents chose 3 or 4, they were awarded HIGH belief in the proposition (✓). When one respondent chose 1 or 2 and the other respondent chose a 3 or 4, they were awarded a MEDIUM belief in the proposition (✓). When the difference between respondents scores is = or > 2, they were awarded a SPLIT belief in the proposition (X).

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Recepción: 2020-09-04. Aceptación: 2020-11-16