Developing a skills-based practical chemistry programme: an integrated, spiral curriculum approach

Undergraduate practical chemistry at Oxford

In common with other UK universities, at the University of Oxford assessment of practical chemistry sits alongside written examinations and a final year research project in contributing to the final degree classification awarded.

We had the opportunity to redesign our practical chemistry course, to coincide with the completion of a new teaching laboratory facility in 2018. Previously, the course was taught separately by three different teams, split along IOP (inorganic, organic, physical) boundaries. In our redesigned course, these teams were unified to create one Chemistry Teaching Laboratory. The new team have complete oversight over practical chemistry course design and delivery in the first three years of the four-year MChem programme. The course redesign gave us the opportunity to rethink how we teach our undergraduate chemistry students practical chemistry. We were able to reassess the skills and qualities we believed a chemistry graduate should possess, and align our teaching accordingly.

A clear set of objectives for the new course was established and laid out in the course Mission Statement:

The overarching aim of the undergraduate practical course is to inspire an awareness, appreciation and enjoyment of practical science. We aim to achieve this by focusing on a number of more specific, tangible aims:

1. To promote safe laboratory working practices;

2. To develop practical and problem-solving skills;

3. To provide an experimental foundation for theoretical concepts and phenomena;

4. To introduce students to scientific practices as used by the scientific community;

5. To promote aspects of scientific thinking;

6. To improve communication skills, including proficiency at scientific writing.

This report details the processes and considerations made in the construction of our new integrated practical chemistry course, placing skills development at its core. In this report, we will focus on the redevelopment of the first-year course. Future publications will follow detailing the second- and third-year course.

A skills-based practical course

In collaboration with chemists from 37 UK higher education institutions, and the RSC, compilation of a Skills Inventory was conducted. The list originated from the ‘Future of Labs’ conference at Oxford in 2015. We led a discussion session, presenting a skills list our team had devised. Participants edited this list anonymously during the session (via Mentimeter) and it was then circulated after the session for participants to make any further comments. The inventory was edited based on the feedback, presented and further refined at national conferences in Oxford in 2017 (‘What makes a Good Lab?’) and 2020 (‘Skills in Chemistry and Physics’).

The skills were classified into 12 separate categories. Within each of the various categories, skills were designated a level, based on expectations of students’ prior experience, theoretical understanding required, technical difficulty and safety considerations. These levels were defined:

1. Basic skills: essential skills needed from year one of the practical course;

2. Intermediate skills: skills that were more theoretically and/or technically more advanced than those in the Basic category;

3. Advanced/Optional: more demanding or specialised skills that built upon and extended those covered in the Intermediate category, aimed towards research level application.

Table 1 shows the full Skills Inventory. Skills categorised as ‘Basic’ are fundamental introductory skills. They are both technically and theoretically accessible at early stages of the student’s degree. These skills provide a foundation and are a gateway to both more advanced and widely used techniques. The more demanding skills form the ‘Intermediate’ skills, which should be completed by students by the end of the practical course.

Skills within the ‘Advanced/Optional’ category require significantly greater technical and theoretical considerations. They may use particular specialised instrumentation or involve more complex operational considerations. These ‘Advanced/Optional’ skills provide students with opportunities to explore particular areas of interest, prior to completion of research in the final year research project. Teaching these skills are opportunities for institutions to showcase their own expertise and specialities.

It should be emphasised that the Skills Inventory was compiled as a means of identifying skills that could be used to form a course, but not as a prescriptive list to be covered by the course. Indeed, we have ourselves distilled this list to fit our facilities and the expertise within our institution. The list covers only the laboratory and laboratory related skills. Laboratory work also fosters numerous transferable skills such as: communication (e.g. oral, scientific writing), team working, organization and time management. Coverage of these transferable skills should be woven into the structure of the whole degree.

Pedagogical considerations

With our established Skills Inventory, we next addressed how teaching these skills could be achieved. Our approach was to develop a practical programme that recognises students’ prior experience and then progressively builds upon this. Our aim is to provide both breadth of exposure to a range of experimental techniques and sufficient repeated experience of these skills to facilitate knowledge retention. The structure of the new course enables students to build a skills portfolio (Wright, Read, Hughes, & Hyde, 2018); parallels here can be drawn with similar initiatives, including the introduction of core skills to the UK A-Level chemistry curriculum, known as the practical endorsement (C. Smith, 2018), the digital badging concept (Hennah & Seery, 2017), and the recent reconstruction of UK introductory chemistry courses (Adams, 2020; Gorman, Holmes, Brooke, Pask, & Mistry, 2021). Our approach expands upon such remits, considering the development of skills across the full undergraduate chemistry practical programme.

Crucially, we set out to impart understanding of why particular techniques/skills were chosen to perform certain tasks, alongside how those techniques are performed. By placing an emphasis on both the “how” and “why”, students hopefully gain a greater appreciation of the practical work they are conducting. This explanation-driven approach has been extensively demonstrated to be more effective than fact driven methods (Bransford, Brown, & Cocking, 2000; Coleman, 1998; Hakkarainen, 2004; Lipponen, 2000). Our vision is to create a course where students are developed into problem-solvers, not recipe followers.

An integrated practical course

A key aspect of developing our new course was considering the best means to reflect the truly integrative nature of chemistry, not as a science segregated into silos. To fulfil our aim for a progressive development programme, we set out our course as a series of specifically developed practicals, rather than separating the practical course by subdiscipline. The design allows for chemistry to be presented as a connected science and in this way, there are opportunities for enrichment of the student experience through multidisciplinary teaching. Similar strategies have been highlighted by Hardy et al.; in their recent publication they discuss the advantages of multidisciplinary teaching in improving affective and cognitive learning and critical thinking (Hardy et al., 2021). We aim to develop a systems-thinking approach in our students, allowing them to think about chemistry more deeply and in a less compartmentalised manner (Mahaffy, Krief, Hopf, Mehta, & Matlin, 2018; Nagarajan & Overton, 2019).

It was important to recognise that each individual practical session does not need to deliver a multi-faceted experience of chemistry; certain skills are sufficiently complex and important to one branch of chemistry that they require individual focus. When possible, we highlight common threads for skills and techniques which are relevant across sub-disciplines. We have been careful to design practicals so that we do not introduce multiple new skills to students in one practical session, with the aim of eliminating cognitive overload.

Repeat exposure and a spiral curriculum

A major challenge for any practical course is ensuring skills retention. Students must be able to recall and execute practical tasks they have had previous experience in performing. In this regard, both confidence and competence are important considerations (Hensiek et al., 2016; Pullen, Thickett, & Bissember, 2018).

We chose to adopt a repeat exposure strategy as a means to solidify key practical skills learnt by our students (Anderson, 1999; Brown & Bennett, 2002). We have aimed to strike a careful balance between repetition to develop confidence, and the potential for repetition to lead to reduced student engagement (Acee et al., 2010; Galloway & Bretz, 2016; Supalo, Humphrey, Mallouk, David Wohlers, & Carlsen, 2016; Trehan, Brar, Arora, & Kad, 1997). As noted by Campitelli and Gobet:

“Rote repetition — simply repeating a task — will not by itself improve performance.” (Campitelli & Gobet, 2011)

“Deliberate practice consists of activities purposely designed to improve performance.” (Campitelli & Gobet, 2011)

It was therefore important that we developed a course where there are sufficient differences each time a skill is revisited. To achieve this, we applied the use of a spiral curriculum. The defining features of this pedagogical approach are outlined below (Harden & Stamper, 1999):

1. Reinforcement—encourages retention of knowledge;

2. Simple to complex—topics can be introduced in a manner to build up complexity, to enable better understanding;

3. Integration—enables connectivity with different aspects of the course to be linked readily;

4. Logical sequence—a logical thread to lead through the various topics can be created at the curriculum design stage;

5. Higher level objectives—the model encourages students to move beyond knowledge recall, to application of knowledge and skills.

The use of spiral curricula has some precedence in secondary education (Bruner, 1977; Schmidkunz & Büttner, 1986) and tertiary chemical education, particularly organic chemistry (Gravert, 2006; Grove, Hershberger, & Bretz, 2008; Minter & Reinecke, 1985; Sartoris, 1992), but is still relatively unexplored in higher education chemistry teaching.

We envisaged a new strategy to teach students requisite practical skills. Early practicals would concentrate on the essence of any new technique. The skill would then be revisited at various later stages, covering more technical aspects and applications of the skill and gradually introducing new chemical theory. The process allows theory and practical skills to be decoupled and provides a mechanism for students to focus on learning the technique at the earlier stages. We believe the strategy provides students with greater opportunities to develop a stronger understanding of each individual skill, whilst also allowing students to create links between concepts when they are revisited.

An important aspect of our redesign was to consider the regularity in which students revisit skills. To emphasise the importance of key skills, students revisit these frequently, both within each year of the practical course and year-on-year as students progress. Throughout their degree, their knowledge and application of the skills is built upon and expanded. When a significant period of time has elapsed since students last practised a skill, we first take a step back to ensure their foundation knowledge is strong; we think of this as ‘winding back the spiral’. The foundation is then built upon and new practical skills or theory are introduced.

Practicals have been designed so that when a skill is encountered frequently, it sits alongside students learning new skills and techniques; in this way it is hoped we can reduce student ennui. By combining the spiral curricular design with an integrated practical chemistry programme, skills can be showcased in multiple scenarios across the disciplines. This approach enables students to develop greater familiarity and confidence in performing practical chemistry in a variety of scenarios, thereby improving students’ effectiveness as future researchers.

The Transition Course: supporting the transition between school and higher education

As part of our new practical course we developed a ‘Transition Course’. This was created in response to reports published by Gagan (Gagan, 2008) and Smith (C. J. Smith, 2012), suggesting that in recent years there has been a decline in the practical skills and problem-solving skills of students entering university. We recognise the differences in educational experiences of our new first-year students and our Transition Course aims to provide a foundation, smoothing over some of the inconsistencies in the students’ pre-university education (Turner, 2019). Several members of our team have extensive experience in teaching chemistry at A-Level and we were able to draw upon their experience in constructing our Transition Course. The course serves to build students’ confidence in the new laboratory setting and provides a grounding for all subsequent practical work.

In choosing content for the Transition Course, we used a range of resources. A review of the practical skills of A-level science students in England was carried out by The Office of Qualifications and Examinations Regulation (Ofqual), in collaboration with a number of UK universities, including our own institution (Cadwallader, 2018). Universities conducted assessments of the practical competencies of their new cohorts across five selected tasks from the A-Level Practical Endorsement. Each institutions’ educators evaluated their new cohort’s practical skills in performing key skills covered during the A-Level programme. Student performance was assessed against a set of prescribed criteria for each of the tasks.

A selection of the data from the compiled report is shown in Table 2. The results from the review helped identify the skills and techniques which would most benefit from being included in our Transition Course.

It is also necessary to introduce some new skills to all the students, at the very beginning of their practical chemistry education. Risk Assessment and Control of Substances Hazardous to Health (COSHH) were deemed essential considerations prior to conducting all practical work, thus it is necessary to introduce this at the very beginning as a new skill. Instruments used routinely for synthetic work are introduced (e.g. IR and NMR spectrometers), so students can gain familiarity with these from the outset. Students study spectroscopy pre-university and our Transition Course builds on this knowledge by teaching students how to use the relevant spectrometers, as well as spectral interpretation.

The key skills in our Transition Course are shown in Table 3. Most of the concepts and tasks were chosen to be familiar to students, thereby reducing the introduction of many new skills at the outset.

The Skills Courses

The Skills Courses are considered a major focus of students’ development in the first two years of the practical course. The emphasis is developing students’ confidence and competency with practical techniques. There are four fundamental aims:

1. to reinforce and revisit techniques with which students would be familiar from their previous experience;

2. to expand the underlying theoretical understanding of the familiar techniques;

3. to illustrate practical applications of techniques and skills;

4. to introduce new techniques that could be utilised throughout their future scientific career.

In the practicals within the Skills Courses, the focus of any particular experiment is to gain familiarity with a new skill or build complexity into a previously encountered skill or technique. The practicals in the Skills Courses were constructed to utilise a small selection of the individual skills in one practical session. For those that were considered more technically demanding or relatively important, we have designed multiple experiments where that particular skill is practised, in a variety of different contexts.

The Core Courses

Practicals in the Core Courses were designed to reinforce skills learnt in the Skills Course. These particular skills are clearly referenced in the laboratory manuals to remind students of their previous experience and students are signposted to the practicals where they previously used these skills. Practicals in the Core Courses are more intellectually challenging; skills and techniques that were learnt previously in the Skills Courses are applied to more complex scientific problems. In experiments in the Core Course, often a broad range of skills are practised in one practical. When skills have been practised repeatedly, gradual de-scaffolding of the laboratory protocol is implemented. This strategy aims to build student confidence and ability to problem solve, and maximise engagement.

The Choice Courses

At the end of the first-year, students have some choice as to the practicals they would like to carry out. This gives them opportunities to investigate areas of chemistry in which they have a particular interest. These experiments are not pre-requisites for any practicals in following years so students do not limit their options by choosing one choice practical over another.

By the end of the second year of the practical course and into the third-year, students will be provided with opportunities to develop some specialisation in areas that interest them most. The labs offered will involve applications of the skills introduced previously or they will introduce new skills. These new skills (shown as advanced in the Skills Inventory) will be related to the use of more specialist equipment. The approach forges important collaborations with research groups within the department and provides students with greater appreciation of the research laboratory environment.

The extended projects aim to provide a stepping stone into students’ final year research projects and will emphasise the integrated nature of chemistry research. The projects will promote student autonomy, allowing students to take responsibility for their own learning (Burnham, 2019). Development of open-ended third-year mini-projects is an evolving aspect of our new undergraduate practical chemistry course and we expect to publish further about these in the future.

Identification of learning objectives

The first step in developing each new practical was identifying the learning objectives; these objectives were kept at the forefront of all practical development work. Using the Skills Inventory, we mapped how skills were developed across each year and across the full practical course.

The learning objectives for each practical are explicitly stated as this allows students to recognise the core skills they are developing when conducting each practical. As students progress throughout each year, significantly more investigative practicals are introduced. This ensures students have opportunities to develop and implement experimental design, formulate hypotheses and interpret their own data. A number of practicals were developed so that students were not able to predict the outcome, even as early as the first-year course. An example of this is the combinatorial discovery of new potential antibiotics based on the guanofuracin framework (Wolkenberg & Su, 2001). In this practical, students devise their own experimental conditions and evaluate the properties of the resulting products.

Pre-lab preparation

As established in the literature, pre-lab exercises are used to guide student preparation before they enter the laboratory. These include pre-lab quizzes (Spagnoli, Rummey, Man, Wills, & Clemons, 2019), videos (Jolley, Wilson, Kelso, O’Brien, & Mason, 2016), and computer simulations (Blackburn, Villa-Marcos, & Williams, 2019). The pre-lab exercises are accessed via our virtual learning environment and are available to students as they progress through the course.

In a departure from previous literature, pre-lab exercises are designed to focus on the practical technique, rather than the underlying theory. Our videos are filmed in house, tailored to our course design and feature the staff and exact laboratory equipment students will be encountering. The pre-lab exercises aim to reduce student cognitive load during the practical by enabling the students to familiarise themselves with techniques before they enter the laboratory.

In-lab

An essential part of learning in the laboratory is communication between undergraduate students and both PhD student demonstrators and teaching staff (Flaherty, Overton, O’Dwyer, Mannix-McNamarra, & Leahy, 2019). We include in-lab questions in the laboratory manual to promote discussion during practical sessions. The questions aim to encourage students to consider the purpose of the steps whenever particular operations are performed.

The laboratory manuals for practicals utilise a mixture of instructional styles throughout the new first-year practical course (Domin, 1999). Practicals that focus on introducing skills are predominantly expository in nature, with explicit procedural instructions given. As students progress through the Skills Course and into the Core Course, scaffolding is gradually reduced.

Post-lab write up

All laboratories are assessed by each student producing a post-lab write up, the requirements for these depend upon the laboratory course. In the Transition Course, post-lab write ups are constructed as worksheets. The students are led through the process of writing up their results and are expected to answer questions about the practical and their experimental data.

In the Skills Courses and Core Courses, scaffolding is removed and students are expected to construct their own post-lab write up. Some guidance is provided in the laboratory manual in the form of post-lab questions; students are expected to provide answers to these in their write up. The write up must then be discussed in person with a member of the teaching team. Here, student’s knowledge and understanding can be explored face-to-face.

Skills-based spiral curriculum: chromatography

The subject of chromatography serves as a suitable example of how we constructed skills spirals in the new practical chemistry course. The theory and applications of chromatography are varied and have uses across all disciplines in chemistry. Thus, a ‘spiral’ of chromatography in its various forms was constructed (Figure 3).

Thin layer chromatography (TLC) is a technique encountered pre-university and students are re-introduced to TLC as an identification technique in the Transition Course. Here, they are also taught the practical technique needed to carry out TLC. In later practicals in the Skills and Core Courses, uses of TLC in synthetic chemistry are introduced, for example its use in reaction monitoring. Moving further up the skills spiral, column chromatography is taught to our first-year students in the Skills Course. Students are taught the fundamentals of silica gel column chromatography in a practical where a mixture of fluorene and fluorenone is separated. In the second year, students extract caffeine from tea bags and purify the product by silica gel column chromatography. In this practical the students are expected to optimise the column conditions.

Finally, more advanced separation techniques are introduced. In the second- and third-year Choice Courses, the concept is expanded to quantification of mixtures by gas chromatography (GC), separation of enantiomers by chiral high performance liquid chromatography (HPLC) and macromolecular separation by size exclusion chromatography.

To achieve such a progression, students are required to gain sufficient theoretical understanding of the scientific processes underpinning chromatography, as well as mastering the practical techniques needed to perform these processes.