To design a lab with purpose, it is important to understand what are (are not) the goals of lab courses. In general, researchers and educators agree that the goals of lab courses are not to recap lectures or to teach cutting-edge techniques but rather to help students develop (a) Scientific Inquiry skills, (b) Disciplinary knowledge and skills, and (c) transversal skills. In other words, to help our students think and behave like scientists.
Therefore, a good lab session will provide students with the opportunity to formulate research questions, analyse, discuss, and solve real problems, in addition to fostering the development of practical, technical and engineering skills. Labs are effective learning experiences when students develop skills for investigating novel situations by learning not only ‘how to do’ the experiment, but also to answer the question ‘why’ am I doing this particular step.
Lab sessions are valuable opportunities to reinforce transversal skills, such as collaborative work, project management skills and problem-solving competences. It is also appropriate to create explicit opportunities for students to learn how to work safely in a lab, to apply critical thinking in new situations, to analyse data, to interpret data, and to record and report procedures and results correctly and professionally.
Traditional ‘cookbook’ laboratory experiments typically provide students with three elements:
- a problem or question,
- a procedure to follow to obtain the necessary information,
- a solution, which may be arrived at through answering the analysis questions or through calculations completed with their experimental data.
While this approach might be effective to learn basic procedures, it has been shown to be less effective to develop conceptual understanding and reasoning skills.
More effective approaches include Inquiry labs, that engage students in
open-ended, student-centred, hands-on activities. These labs can vary in the amount of scaffolding that is provided to the students:
- Structured inquiry: The teacher provides the question (open-ended) and a prescribed procedure.
- Guided inquiry: The teacher presents an open-ended question and the student designs the procedure
- Open inquiry: The student comes up with the questions and the procedures.
The approach you choose will depend on your context as well as comfort level, and can change as you get more teaching experience.
The example below from D. Pioletti’s course Experimental methods in biomechanics represents the entire lab assignment given to Ba6 ME students:
Context: In regenerative medicine, different cell types are used to promote healing and regeneration. The treatment of cartilaginous lesions of the knee is one example. In order to have a minimally invasive procedure, these cells are injected through the needle of a syringe. The higher the number of viable cells injected, the more effective the therapy. However, the comfort of the patient also needs to be considered.
Question 1. What are the different « biomechanical events » that the cells will undergo during the injection through a syringe and its needle?
Question 2. How can you determine the effects of these « events » on cell viability?
Question 3. What solution would you suggest to optimally inject the cells into a patient?
Students, working in small groups, decide what data they need to answer the questions and design an appropriate protocol. Each group investigates slightly different parameters with a slightly different approach. This autonomy to try, to make decisions, and to defend their findings allows D. Pioletti’s students to develop authentic experimental skills.
At University of Rhode Island
- Gindy & G. Tsiatas, give the following lab assignment to their students:
You are provided with two steel truss structures similar to those used in previous labs. One of the trusses is damaged while the other is not. Your task is to identify the damaged structure using measurements and simulations, prepare a preliminary report describing the testing approach and methodology used to make your decision, and propose a test plan for locating and assessing the type and degree of damage including the type, number, and location of sensors, experimental methods, and expected outcomes.
In this instance, one group of students proposed to assess the truss’ vibrational properties using an impulse hammer and accelerometers, while a second group evaluated the strain and displacement signature of the structure under controlled loading using different methods.
Students often do not understand that the lab notebook should be a complete record of procedures undertaken, including rough observations and nascent ideas or explanations generated during the experiment. Rather, students consider that the goal of the notebook is to produce a clean, linear presentation of the ‘perfect’ experiment and not an authentic account of their actions and findings. In doing so, they miss out on capturing the complex, creative, and authentic facets of real research. Care thus needs to be taken when setting grading criteria so that students do not aim to give you a sterile account, but instead provide their authentic experiences. Discovery or inquiry labs, where students are not simply replicating a set procedure, are well suited to learning to appreciate the role of a notebook.
It is appropriate to assist students in choosing equipment for keeping a notebook (either paper or electronic; ELN is used by the SV faculty) and in establishing a structure for organising their records. Furthermore, students should learn to see their lab notebook as a legal document important for future patent applications or refuting allegations of research fraud.
Asking questions is an important way to check on student understanding, and to keep students moving in the right direction. The questions you ask may depend on what stage the students are at in the lab. Here are some questions that you might expect to pose to students:
- Initial stages: What do you expect to see and why? What looks like it is going to be difficult to measure/ assess/ evaluate and why? What equations/ theorems/ frameworks do you expect to apply?
- In progress: What sorts of things are you taking notes on? Are your observations what you expected? Why do you think that happened? What are you going to do next and why?
- Concluding stages: Have you thought about how you will do the write up? What have you got out of today? How does today’s experiment relate to what you have learned before?
When answering questions, try to make sure that the students are doing most of the thinking (rather than relying on you or a TA) by reframing their questions or asking leading questions that prompt them to work it out themselves. You can also suggest that students discuss with another group, review their course notes or refer to a reference book.