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Teaching Laboratory Sessions

Laboratory sessions provide students with opportunities to apply concepts, develop practical skills, solve problems, and engage directly with disciplinary practices. As a laboratory TA, your role may involve supervising experiments or activities, answering questions, facilitating discussions, monitoring safety, providing feedback, and helping create a supportive learning environment.

Your responsibilities as a laboratory TA will likely depend on the course, discipline, and guidance provided by the course instructor or lab coordinator. This page provides some general strategies and considerations to help you get started.

 

Clarify Your Role and Responsibilities

Before leading or supporting a lab session, it can be helpful to meet with the course instructor or lead TA to discuss expectations, responsibilities, and logistics. Laboratory environments can vary significantly across courses and disciplines, so asking questions early can help prevent confusion later in the semester.

Some helpful questions to consider include:

  • What are the goals and learning outcomes of the laboratory sessions?
  • What safety procedures or protocols should students follow?
  • What responsibilities will I have during the lab?
  • How should I support students when they are struggling?
  • What level of guidance should I provide during activities?
  • How should grading and feedback be handled?
  • Are there rubrics, answer keys, or grading guidelines available?
  • What should I do if safety concerns or unexpected situations arise?

Preparing for the Lab Session

Preparing for a lab session involves more than reviewing the content. It also means understanding the goals of the lab, anticipating where students may need support, reviewing safety expectations, and knowing what to do if something does not go as planned.

Prioritize Safety

Creating and maintaining a safe learning environment should always be a priority in laboratory settings. Depending on the discipline, this may involve physical safety procedures, equipment protocols, chemical handling, ethical considerations, digital safety practices, or other forms of risk management.

Before the lab session, familiarize yourself with:

  • Laboratory safety protocols and emergency procedures
  • Required protective equipment or materials
  • Accessibility considerations
  • Procedures for reporting accidents or concerns
  • Safety expectations students are expected to follow

If you are unsure about a procedure, expectation, or activity, ask for clarification before the session begins. You should never feel pressured to perform tasks you are uncomfortable or untrained to complete.

Review the Lab Activities and Materials

Before the session, take time to review the lab activity, procedure, equipment, and related course concepts. Being familiar with the activity can help you anticipate questions, identify potential stumbling blocks, and support students more confidently during the lab.

As you prepare, consider:

  • What are students expected to know or be able to do by the end of the lab?
  • What theory, content, or procedures should you review in advance?
  • Can you try out the lab activity, equipment, or procedure before students complete it?
  • Where might students become confused, stuck, or unsure of the next step?
  • What materials, instructions, or technologies will students need during the session?
  • What should you do if there is an equipment issue, disruption, or unexpected result?

If grading is part of your role, it can also be helpful to review assignment instructions, rubrics, marking guidelines, and any relevant course policies before the lab begins.

Create a Welcoming Laboratory Environment

Students are more likely to participate, ask questions, and take risks in their learning when they feel respected, supported, and included. Laboratory sessions can sometimes feel intimidating, particularly when students are learning new equipment, procedures, or technical skills.

Small actions can help create a more welcoming environment, such as:

  • Learning and correctly pronouncing student names when possible
  • Encouraging questions and curiosity
  • Recognizing that students may have different levels of prior experience
  • Normalizing mistakes as part of the learning process
  • Creating opportunities for collaboration and discussion

Students may also need reassurance that it is okay not to immediately know the correct answer or procedure. Labs are often spaces for experimentation, practice, troubleshooting, and skill development.

 

Facilitating the Lab Session

Laboratory sessions often move quickly and may involve demonstrations, troubleshooting, questions, and safety reminders happening at the same time. Having a general plan for how you will start, support, and wrap up the lab can help students feel more prepared and confident throughout the session.

Starting the Lab

The beginning of the lab helps set expectations and prepare students for the session ahead. A short pre-lab introduction can help students understand the purpose of the lab, important procedures, and key safety considerations before they begin working.

At the start of the lab, it can be helpful to:

  • Clarify the goals or learning outcomes for the lab
  • Connect the lab to previous lectures, labs, or course concepts
  • Outline the major lab activities or key steps for the session
  • Break demonstrations into smaller, meaningful stages
  • Review important safety protocols and expectations
  • Leave time for questions before students begin

During the Lab

As students work through the lab, circulate throughout the room and check in regularly. Monitoring student progress can help you identify confusion early, address safety concerns, and create opportunities for students to ask questions.

Rather than immediately providing answers, consider using an inquiry-based approach to guide students through the thinking process. Asking process questions can help students troubleshoot challenges, reflect on their reasoning, and build confidence in their problem-solving skills.

For example:

  • "Can you walk me through what you have tried so far?"
  • "What result were you expecting?"
  • "What do you notice about the data?"
  • "What does the procedure suggest?"
  • "What do you think might have happened here?"

If results are not as expected, encourage students to think through possible explanations rather than focusing only on the "correct" outcome.

At the same time, students should still feel supported. If students become stuck, frustrated, or confused, consider offering prompts, clarification, examples, or partial guidance to help them move forward.

Supporting Questions and Common Issues

Encourage students to ask questions, especially when they are working with unfamiliar equipment, procedures, or technical skills.

If several students are asking similar questions, consider pausing briefly to address the whole class or a small group rather than repeating the same explanation multiple times.

If you are unsure of an answer...

It is okay to acknowledge that you need to check. For example: "I’m not completely sure, but I'll confirm and follow up."

Providing accurate information is more important than answering immediately.

Ending the Lab

Leaving time at the end of the lab for cleanup, questions, and reflection can help students consolidate their learning and leave the space safely and respectfully.

At the end of the session, it can be helpful to:

  • Summarize important results, concepts, or takeaways
  • Review common challenges or misconceptions
  • Answer final questions
  • Review next steps or upcoming deadlines

You should also leave enough time for cleanup and ensure students return equipment and materials appropriately before leaving the space.

After the Lab

After the session, take a few minutes to reflect on what went well and what may need adjustment next time. This can also be a good time to review student work for common errors, note areas where students struggled, and share feedback with the teaching team.

Teaching in laboratory settings gets easier with practice. Checking in with other TAs, lead TAs, or the course instructor can help you troubleshoot challenges and continue developing confidence in your role.

 

Attribution

This page was adapted from 4 Key Questions for Teaching Assistants in Lab Settings by the Centre for Teaching and Learning, Queen's University and is shared under a CC BY-NC-SA license.