Laboratory sessions / TP

Getting hands-on

Designing labs

Good lab sessions provide students with the opportunity to 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 understand not only how to do the experiment, but why the concept or process is important in their studies and how it might be applied or connected to real world situations.

Traditional 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, disparagingly called ‘cookbook’, is generally effective for having students learn basic procedures, it has been shown to be less effective for developing conceptual understanding and reasoning skills. More effective approaches include providing students with only:

  • a problem + procedure, requiring them to develop their own analysis and discussion.
  • a problem, requiring them to develop their own procedure + analysis (this is called inquiry-based).
  • a concept or issue to be explored, requiring them to set an appropriate problem, develop a procedure and analysis (discovery-based).

For example, a discovery-based lab assignment from M. Gindy & G. Tsiatas, University of Rhode Island gives the following instruction to 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.

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.

Appreciating the importance of the lab notebook

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 may perceive the goal of the notebook as being 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 and creative side of real research. Care thus needs to be taken when setting grading criteria so that students do not simply try to give you what they think you want, but instead take seriously the idea that it is their notebook describing their own 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 appropriate equipment for keeping a notebook, either paper or electronic (for example lims in SV), 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.

Supporting thinking in labs

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? What looks like it is going to be difficult to measure/assess/evaluate? 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?
  • 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 the course?

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.

You can register to the workshop ‘Effective TP and labs’ offered by CAPE, or contact a Teaching Advisor for assistance finding resources for your field.

Laboratory