Being an effective lab TA

Supervising a lab poses specific challenges that are not found in other teaching environments. Safety must be considered at all times, and group learning environments can be difficult to control. Suggestions to help you perform most effectively during three main areas of lab-related teaching are given below.

Pre-lab talks

  • Pre-lab talks should be brief, to the point and given with a welcoming tone and posture.
  • Pay attention to acoustics, lighting, noise level and sight lines of the room.
  • Announce your name and availability.
  • Provide the background to, or theoretical context of, the lab exercise as it relates to the lecture.
  • Determine the average background knowledge of the class and suggest reference materials.
  • Define new and specialized terminology.
  • Give a clear explanation of the lab objectives from the students’ perspective
  • Describe the timeframe of the lab period.
  • Clarify when you expect students to work in groups as opposed to individuals.
  • Highlight safety and/or ethical issues.
  • Provide non-threatening opportunities for questions throughout the lab session.


  • Make sure that everyone is seated in a location where they can experience the intended effect of the demonstration.
  • Explain the context of the demonstration and its connection to theoretical material.
  • Break the demonstration into steps and show these steps in chronological order.
  • Highlight interesting, tricky, or dangerous steps.
  • Perform once slowly, then once at real-time speed.
  • Illustrate the expected outcome.
  • List common problems and suggest troubleshooting methods.
  • Provide written instructions.
  • Question students to check their understanding.

Checklist for effective over-the-shoulder help

  • Encourage interaction with instructors and be available as a coach.
  • Observe body language to determine which students are feeling confident, lost, frightened, etc.
  • Ask quiet students if they are having trouble or are they just thinking.
  • Provide specific, encouraging, feedback.
  • Ask thought-provoking questions to help keep investigations rolling: “what would you predict would happen if…?” “what are you assuming?”
  • Beware of “do my thinking for me” questions: respond with leading questions of your own that help students discover the answer.
  • Be vigilant regarding safety hazards.
  • Flash lights etc. to get attention of class before making announcements.