DECONSTRUCTING THE LAB PRACTICAL

LAB

Sinclair Refining laboratory… at Corpus Christi Texas, by Robert Yarnall Richie via DeGolyer Library, Southern Methodist University https://www.flickr.com/photos/smu_cul_digitalcollections/8409510090 (no copyright restrictions)

Enhancing learning in lab-based science education through re-designing assessment practices

Yesterday we had a really successful seminar with @seerym (Michael Seery) and @Breebio (Ronan Bree) opening up the lab practical for critical and practical inquiry.  The event attracted attracted over 40 colleagues from @NUIG including technical officers, post-doctoral students, educational technologists and academic developers, as well as lecturers.

In this post I will focus on the challenges offered by Michael’s contribution.

Michael was asked to problematise the lab practical as it normally appears in the science curriculum in higher education.  Those who know Michael’s work will be aware that unpacking the role of the lab practical has been a central focus of his work, so much so that he is endeavouring to write a book on the subject. An interesting resource on the ideas covered in the seminar is a post by Michael last year.  I will make some reference to it here.  The seminar offered Michael an opportunity to rehearse the central argument of his book.  I will try to outline some of the central issues and questions below.

  • Lab practicals, contrary to the professional discourse, do not warrant the effort expended on them
  • Despite the claims made that practical classes reinforce the theory and develop core skills there is no evidence to support this
  • The usual model for organising practicals result in negligible learning gains, over assess students without resulting in incremental improvements in either theoretical understanding or scientific skills, and have no demonstrable link with lecture series.

Practical classes can often be epitomised by the rush for the door where students correctly read the deep structure of the classes as being to get the experiment done as quickly as possible, write the lab report, and leave.  An average undergraduate can produce at least 125 lab reports without there being any substantial improvement in their scientific knowledge over that period related to the lab practicals.

Instead of making the false assumption that practical classes are locations for teaching theory, Michael, along with others, propose a different presumption

  • Organise lab practicals and lectures separately, each having a distinct function
  • Lectures become the means by which students are invited to engage with disciplinary knowledge, core concepts, troublesome knowledge, threshold concepts, etc.
  • Lab practicals then become the vehicles for developing and practicing disciplinary ways of doing, of practicing the scientific method. [I hope I have this distinction right…I’m sure Michael will correct me]

A number of practical ideas were offered to illustrate what a lab curriculum could look like.  I will focus on just a few.

  • Keep the traditional deductive approach but include decision points
    • Michael argued that there was nothing particularly wrong with the traditional deductive approach of practical classes.  Lab work should operate within a knowledge framework but should free itself from a ‘cook book’ approach.  The experiment would be organised around a series of decision points, where students would need to make informed choices about possible routes (having compared entity 1 with entity 2) what method would I use to test (hypothesis x)…I think.
  • Fewer but more powerful assessment points
    • There is no logical or necessary reason why students should have to produce a report for every lab.  Rather than producing 12 reports for a series of 12 labs why not 3 more substantive and focused assessment points which require students to go deeper into the topic/skill and educators to provide useful formative assessment.  In addition why not organise the assessment points so that each point build a basis for the next set of labs and assessment?
    • Based on the theory of cognitive load Michael suggested that assessment could focus on specific skill sets rather than being assessed on every dimension of the experiment.
  • Lab reports can simulate the research article
    • Michael suggested that lab reports should support the rationale that lab practicals develop disciplinary ways of doing and being by emulating the research article.
  • Diversify the modes of reporting
    • While lab reports might be perfect for some forms of assessment we should consider other modes of reporting learning.  One example provided was that of students using mobile devices to video each other practicing certain lab skills and then peer assessing this (with the added advantage that the videos can go into students’ portfolios and be used in securing internships or even jobs).

Certainly a lot of food for thought and I will certainly be back to discuss this again.

 

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headache…

Julius Axelrod

The image above is that of Julius Axelrod who, with Bernard Brodie, is seen as establishing paracetamol as a leading painkiller.

So, why Axelrod, why paracetamol?

A previous post introduced the idea of me using this blog to develop and rehearse my thinking leading to an academic article (hopefully), inspired by my observation of a pharmacology laboratory practical class.  The focus of this class was a test of the toxicity of paracetamol solutions.  This has a very practical rationale because paracetamol poisoning is so common, hence the importance of those dispensing the drug having a proper understanding of its adverse effects.

As I observed the students engaging in the ‘paracetamol array’ I was taken by the performative character of the activity.  The activity was ‘staged’ in the sense of being performed in a particular setting that gave the activity certain meaning.  Imagine this cluster of young people dressed in white lab coats conducting this test in the student bar?  In being wrenched from the lab its ‘meaning’ would change, there would be an ‘out-of-placeness’ about it; the authority and legitimacy of the activity as SCIENCE would be in question.  WHERE the array was conducted was important.  There was a distinct patterning to the movement of the students between paper, apparatus, chemical compound, and back to paper; or between the pairs of students working together (?) at their bench.

This notion of performance is important here as a key concept in posthuman understandings of science, indeed of helping me understand the activity as science.

So, in what sense might we say these students were engaged in science?

Let me begin with a very brief description of the setting (though I will give more detail of the activity later).

The space within which the activity took place was undoubtedly a ‘laboratory’ something like this,

CICB's_Laboratory

with approximately 50 students wearing white lab coats.  It had all the semiotic clues that would lead most observers to conclude that what was going on in this space was science. The benches and the other non-human artefacts – measuring instruments and machines, as well as water and various chemicals function both as ‘tools’ that enable the practices of scientific endeavour (and science education in this case) but also as ‘signs’, signaling a particular meaning to the practices undertaken in this space.

This sense of scientific activity immediately begins to break down the distinctions between science as knowledge and science as practice.  And it is this latter sense of scientific endeavour that has preoccupied the work of Andrew Pickering.  Andrew Pickering draws attention to the cultural portrayal of science as primarily cognitive, certainly a conception carried in higher education:

Scientists feature as disembodied intellects making knowledge in a field of facts and observations (and language, as the reflexivists remind us)

Andrew Pickering (1995) The Mangle of Practice: Time, Agency, & Science, Chicago: Chicago University Press (see also here)

Through a series of studies Andrew Pickering deconstructs the cultural motifs of scientific work and demonstrates the folding together of human and non-human activity, and in going beyond ‘science-as-knowledge’ he argues that this takes us to an understanding of science-as-performance.

This performative understanding of science turns many common-sense notions on their head.  Such notions can lead us to perceive the world as one where ‘facts’ and ‘events’ are there to be found and observed respectively.  Instead, Andrew Pickering conjures up a world of agency – human and non-human.

He uses the example of the weather to illustrate this. Weather acts upon us without us willing it.  Our response to weather is not purely cognitive, but requires non-human materiality in the form of clothes and shelter.  But clothes and shelter have to be understood as not simply extensions of human thought and action, as things that emanate from a human origin (usually understood as cognition).  While cognition plays a part, our responses cannot be reduced to the purely human realm.  Also, the non-human material world does not act simply as ‘tools’ (as things to keep us safe from the weather).  The constituent elements that make up clothes and shelter will continue to ‘do things’ – that is have effects regardless of human action.  It is not the clothes and shelter that have material agency, but the physical and chemical properties of their constituent elements.  However, conjoined with human action and thought they may  have particular effects, which then impact upon human action and thought – human behaviour and thought changing as a consequence of new capabilities afforded by clothing and shelter.  It seems common-sense but for the fact that this understanding often appears missing in everyday language – including academic and scientific.

This is best illustrated with reference to the relationship between scientific knowledge and scientific apparatus/machines, and especially the concept of temporal emergence.  But before I do that I need to briefly outline the process the students followed in the lab:

 The students were required to conduct a colorimetric assay of a paracetamol solution in order to determine the therapeutic/toxic concentration.

The assay involved the students following a procedure similar to this below:

Preparation of a series of paracetamol solutions (some with known concentrations and some ‘unknown’) for comparative purposes involving processes of measuring (weighing and liquid measures), use of various apparatus (pipettes, including eppendorf pipettes, flasks, vortex machine for mixing, spectrophotometer), and a number of chemical compounds (water, sodium nitrate, sodium hydroxide).

Based on the reading from the spectrophotometer the students then had to construct a standard curve (based on Beer’s Law) and determine the concentration of paracetamol in the samples of ‘unknown’ toxicity.

 posthuman

Pickering’s discussion focuses on the relationship between scientific thought, practice and the apparatus (or machines) in the particular examples he investigates.  Scientific ‘machines’ work to inscribe material (non-human) agency.  He explores how in practice the development of scientific knowledge and practice operates like a ‘dance of agency’ between human and non-human with machines mediating this.

Let me try to illustrate this dance of agency as it might appear in the observed pharmacology lab by trying to distinguish between the moments of human and non-human agency:

Human Activity

  • reading array instructions
  • discussion with lab partner
  • measuring (water, paracetamol, acid, etc.)
  • dispensing solutions into test tubes
  • operating vortex machine
  • recording process and results

Human Passivity

  • waiting for the solutions to mix and settle

[during this period it is the material agency of the mixture that takes the lead and the students can do nothing but wait.]

Human Agency

  • placing samples into the spectrophotometer 

Human Passivity

  • waiting for the spectrophotometer to produce the results from the interaction between the basic materials (paracetamol) and the machine

Human Agency

  • interpreting the results from the spectrophotometer
  • charting the graph (based on Beer’s Law) and locating the toxicity of the ‘unknowns’
  • recording and reporting the results

 

 

It is within this dance of agency that something called learning occurs.

We can perhaps view this as patterned activity in the sense of a grammar of practice where this grammar does not provide us with the specifics of each articulation.  While there will be a grammar to the students’ practice in the lab, we cannot know in advance what the particular articulations of learning will be in the interaction of human/non-human.  In this regard, learning objectives simply outline the teacher’s (or scientist’s) intentions, but in the end learning will be emergent often relating to specific tasks and problems; learning cannot be predicted other than in the doing of the array. Learning is an accomplished activity rather than a simple acquisition of external knowledge or cognitive activity. Learning is something that occurs in the completeness of the doing, and embodied and situated accomplishment (this will be explored in a further post).

Temporal emergence, then,  might be seen as relating the students’ emergent learning outcomes (ELOs).  These ELOs might develop in real-time (hence the emphasis on ‘temporal’) shifting from a concentration on the knowledge domain, to the need to align their partner to the task-in-hand, to just ‘getting through the day’, to recognition of a psychological resistance to some element of the course.

As part of the temporal emergence of their learning the student might usefully be seen struggling with aligning themselves to the task-in-hand, of applying the necessary protocols (following the instructions for measuring and mixing) for the array and their conceptual understanding (of chemical processes and their practical application).  There could be an iterative relationship between the grasp of the process and their conceptual understanding.  This would mostly likely be more visible or pronounced when something didn’t work (requiring a process of reverse engineering to see what happened).

I will come back to this idea of the way the materiality of the lab and the practical actions of lab-work ‘carry’ knowledge and understanding in another post.


Here, I have tried to relay my current understanding of a complex interpretation of scientific practice through a posthuman lens and its possible application to higher education learning.

Further posts in this series will explore the materiality of lab-work and how this ‘carries’ learning; the organised nature of learning as a social activity of alignment.

In the writing of these posts I am struggling with ideas that take me beyond my habitual zones of practice.  By the time I write another iteration of this it is likely that I will have altered some of my understandings.  It should go without saying that any comments and suggestions from readers would be vital in this process.