I have been reading quite a lot about why we do practical work. Laboratory work is a core component of the chemistry (science) curriculum but its ubiquity means that we rarely stop to consider its purpose explicitly. This leads to many problems. An interesting quote summarises one:
One of the interesting things about laboratories is that there has never been definite consensus about those serious purposes. Perhaps that is why they have remained popular: they can be thought to support almost any aim of teaching.1
Even within institutions, where their might be some prescription of what the purpose is in broad terms, different faculty involved in the laboratory may have different emphases, and subsequently the message about what the purpose of practical work is differs depending on who is running the lab on a given day.2
This matters for various reasons. The first is that if there is confusion about the purpose of practical work, then everyone involved will place their attention onto the part that they think is most important. Academics will likely consider overarching goals, with students developing scientific skills and nature of science aspects.3 Demonstrators will think about teaching how to use instruments or complete techniques. Students will follow the money, and focus on the assessment, usually the lab report, which means their time is best utilised by getting the results as quickly as possible and getting out of the lab.4 Everybody’s priority is different because the purposes were never made clear. As in crystalline.
The second reason that thinking about purposes is that without an explicit consideration of what the purposes of practical work are, it is difficult to challenge these purposes, and consider their value. How many lab manuals open up with a line similar to: “The purpose of these practicals is to reaffirm theory taught in lectures…”? The notion that the purpose of practicals is in somehow supplementing taught material in lectures has long come in for criticism, and has little basis in evidence. Laboratories are generally quite inefficient places to “teach” theory. Woolnough and Allsop argued vehemently for cutting the “Gordian Knot” between theory and practical, arguing that practical settings offered their own unique purpose that, rather than being subservient to theory work, complemented it.5 Kirchner picks this argument up, describing science education in terms of substantive structure and syntactical structure. The former deals with the knowledge base of science, the latter with the acts of how we do science.6 Anderson had earlier distinguished between “science” and “sciencing”.7
Discussion therefore needs to focus on what this syntactical structure is – what is “sciencing”? Here, the literature is vast, and often contradictory. To make a start, we look to Johnstone who, with his usual pragmatism, distinguished between aims of practical work (what we set out to do) and objectives of practical work (what the students achieve).8 With this in mind, we can begin to have some serious discussion about what we want practical work to achieve in our curricula.
- White, R. T., The link between the laboratory and learning. International Journal of Science Education 1996, 18 (7), 761-774.
- Boud, D.; Dunn, J.; Hegarty-Hazel, E., Teaching in laboratories. Society for Research into Higher Education & NFER-Nelson Guildford, Surrey, UK: 1986.
- Bretz, S. L.; Fay, M.; Bruck, L. B.; Towns, M. H., What faculty interviews reveal about meaningful learning in the undergraduate chemistry laboratory. Journal of Chemical Education 2013, 90 (3), 281-288.
- (a) DeKorver, B. K.; Towns, M. H., General Chemistry Students’ Goals for Chemistry Laboratory Coursework. Journal of Chemical Education 2015, 92 (12), 2031-2037; (b) DeKorver, B. K.; Towns, M. H., Upper-level undergraduate chemistry students’ goals for their laboratory coursework. Journal of Research in Science Teaching 2016, 53 (8), 1198-1215.
- Woolnough, B. E.; Allsop, T., Practical work in science. Cambridge University Press: 1985.
- Kirschner, P. A., Epistemology, practical work and academic skills in science education. Science & Education 1992, 1 (3), 273-299.
- Anderson, R. O., The experience of science: A new perspective for laboratory teaching. Teachers College Press, Columbia University: New York, 1976.
- Johnstone, A. H.; Al-Shuaili, A., Learning in the laboratory; some thoughts from the literature. University Chemistry Education 2001, 5 (2), 42-51.
14 thoughts on “What is the purpose of practical work?”
A major aspect that I focused on when teaching practical work was in students reading the instructions and doing the Rosk Assessment before they start. I was also shocked to discover that teachers in other schools, even at ‘A’ Level, didn’t insist on students writing a proper lab report. This prompted me to ask various university lecturers if this was still a desired/ required skill for undergraduates to have before they start university ( I had electronic notebooks in mind, which were just becoming available when I left research). They replied that it’s an essential skill that many incoming students no longer have.
“Purpose” is a question I too have pondered frequently and agree that to answer it we must consider both perspectives, teacher and student, then afterwards reflect upon the extent to which the “purpose” of each has been realised.
As a school teacher I can’t get away from the curriculum and what will enable my students to progress to the next stage of their education. Time is the limiting factor but engagement is essential and fortunately practical work is engaging but some students are actively engaged where as others passive, sitting back and viewing the events unfold for their entertainment (cf. magic trick?). So the question evolves from “purpose” to “purpose, impetus, outcome” which requires some sort of assessment criteria that avoids obfuscating the original “purpose”. Now the lab report for example, to what extent does that help me assess the students’ understanding of a concept or indeed if they can relate the observed phenomena to the intended concept? Or how does a written commentary support the development of practical skills -other than report writing.
So “purpose”; practical skill development, observation of phenomena, observation of phenomena to develop conceptual understanding, working scientifically curriculum requirement, working scientifically including report writing with a view to further study, engagement and passing exams…
Working scientifically is a nice one to consider. The challenge is getting that to work in a mass system. If only there was a way……………………….!
Further more how does micro scale affect the “purpose”?
This is a very BIG question…. As someone who teaches A level I will always say that it is not my job to train chemists ready for HE laboratory work, relatively few of the 50,000 pupils a year who take A level chemistry will actually go on to study chemistry. When assessment and grades were tied to practical work then they narrowed the diet of practical work to a few artificial exercises that were practised to infinity in order to get the required accuracy. Maybe a wider goal (maybe for the RSC?) needs to be defining the role of laboratory work at each stage of a student’s learning in chemistry. For those teaching in schools there is a good tracker for the purpose of practical work in the RSC chemistry for non specialists book which allows teachers to track whether they are simply repeating the same objective each time.
Thanks for the pointer to the non specialist info. Would be interesting to read that. I’m not too optimistic about RSC setting out goals for lab work but they would have great scope through accreditation process. My breath isn’t held.
I’ll dig you a copy out when I am back at the chalk face.
I would love to have a big debate about this with representation from teachers at all staged from upper primary through to HE. I suspect that school teachers would lose though…
Be careful what you wish for when you doubt some of the aims of practical work. There are the bean-counters out there (accountants) and as labs are extremely expensive parts of any school building, any savings that can be made in reducing lab area will be taken and you will never get it back. (Expensive fee-paying Independent schools will be an exception.) There is evidence of this in new builds. And yes, if we cut the labs down we do not require the technicians, so further savings. (UK is in a minority in having technicians. In other countries teachers are given extra time to do their lab preparation. Allowing for preparation and disposal is not in the psyche of our school management. I went to a school in Germany with no technicians but teachers who loved practical work and you should have seen the state of the preparation area!)
But I have a lot of sympathy in your questioning and aims. My microscale techniques started off as combating fears of safety stopping practical work and developing less expensive alternatives in the 1990s. I am not advocating that all practical is microscale by the way.
“Time is the limiting factor” This is an important bonus of the microscale approach. Now I am exploring the interpretation of chemical events to provide evidence.
(I can do a 10 titrations in drops from fine-tip pipettes in the same time I can do titrations using 50 ml burettes and they give similar results to those from expensive burettes. But removing the paraphernalia is a complete no-no to traditionalists from the outset, as “burettes are required in the exam”. Titration is so complicated to most students, we need progression and we can progress from simple drops to the large scale when they have to climb on a step ladder to read a 50 ml burette.
So are we teaching students to be a chemist or are we teaching them to understand chemistry.
Well I am just an old crusty nerd now but I interested Michael Seery when I asked him to see some of this work. You won’t see it though because all the workshops I put on are cancelled because of financial constraints on CPD. But see http://michaelseery.com/home/index.php/2016/10/a-tour-around-johnstones-triangle/ .
But an Exam Board has taken the ideas so that keeps me going.
Also see the the website http://www.microchemuk.weebly.com
Workshop in Leicester on May 11th. Not holding out great hopes though.
Thanks… I suppose my point is that if we go around saying practical work is great for teaching concepts but there is no evidence for this, the bean counters will be able to say with some justification that there is no need for labs. We should be loud and clear about the complementary role practical work plays, and the outcomes it achieves beyond what just book work can do. Practicals originally came in because it was felt demonstrations weren’t sufficient. So what is it that practical work achieves?
Interesting point about titration are you aware that it is now met in the first half of the first year of GCSE in most English specs? Someone somewhere really views it as important; me I enjoy it and find it a great context for mole calculations.
Naomi: Well you understand titrations and mole calculations. But technicians report to CLEAPSS that the students treat the apparatus very poorly and either breaking the barrel by clamping too hard (“why haven’t they got burette holders? Well they are having budget cuts and if photocopying is included at outrageous prices that is soon used up!) or they twist the tap too hard and break the stem. Then there are poor instructions from teachers not properly trained themselves, not even chemists.
Only last year we have had a case go to court where a pupil was severely burned in the mouth by pipetting 1M sodium hydroxide by mouth because the pipette fillers they had were poor. (I have had teachers criticise CLEAPSS and me on the phone for insisting that fillers are used instead of pipetting by mouth.) There are poor instructions in books about using 2M solutions in burettes for thermometric titrations and making soluble salts. You, as a trained chemist, will know that that titration is carried out by solutions in 0.01 to 0.2M range. Then every spec from the board has 50 ml burettes which when on the bench are so high that students aged 14 cannot read them at eye level. What is wrong with a 10 or 25 ml burette? Instructions will specify a 25 ml pipette. Well what about 10 and 20 ml pipettes? The 50 ml burette and 25 ml pipette are used in industrial labs for analysis. They were also used “when I was a lad” in 1960 so they must be correct. I asked one 3rd year student at a top University last year how often she had carried out a titration at University and they answer was once. Then these students are expected to go into a school and teach it. That school may not have a chemistry specialist. (PS she had never used a Bunsen at University because they had electrical heating, in fact safety had stopped gas being installed in the laboratory.)
I once took a group of students around an orange drink company in the 1980s. As we looked down on the lab there were banks of burettes. “We have those” cried a boy. A moment of pride passed over me. The company no longer exists. I wonder though what the titration situation of food testing is now. Is it all automatic titration now? What happens in our water testing stations? Is this a skill our Industrialists and Academics are after? As you say “Someone somewhere really views it as important;” and yes I enjoy it too.
And oh yes, I have just screened an A level set experiment for safety where a titration is carried out. There is no mole calculation. All they have to do is come up with the titre volume. I muttered” what is the ****** point of that?”
Yes, it was a matter of pride for me, when at school, college and university to obtain 3 titrations to within 0.10c.c. I loved doing titrations. Another point of practical work. E.g. Titrations is to record data to a sufficient number of sig. figs. I only had to be taught this once, but for some reason, I have to re-inform my students time and time again. We were taught not to put alkali into the burette, but I keep coming across standard practical instructions telling students to do just that!
Thank you for your comments, you are absolutely right it is vital to think of the bigger picture and take into consideration all that can go wrong. I myself get very frustrated with poor kit and take the view that we should do things by the book -well exam board. The current funding cuts will be making matters worse. I am happy to use micro methods and indeed would advocate their use as often as possible but for core practical work I will stick as close as possible to the exam board; just in case!
I think perhaps the most important point raised is that of training and its impact on health and safety. Are teachers and technicians offered the training necessary to operate safely? Is there a great enough focus on hazard and risk in lessons?
I think one of my biggest problems with the idea of labs being used to reaffirm theory taught in lectures, as a student, is that lab schedules and lecture schedules often don’t run in sync. It’s very frustrating to have to try and teach yourself some theory to understand a lab, only to cover the content two weeks later in class.
Personally I think that what I think I’ve gained the most from labs is practical skill and understanding of technique. Although, I’ll admit that I’ll be guilty of trying to get out the lab as fast as possible.
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