Chemistry lab with
Fei Ding, an international TA.
a laboratory instructor, you teach students how to learn by doing; at
the same time, you motivate, teach, and encourage them individually. Because
only a relatively small number of students can work in a lab setting at
one time, you have the chance to interact closely with your students.
You may also be responsible for grading their work, even in labs accompanying
your role as a lab instructor will vary somewhat depending on your discipline,
some general precepts apply. Above all, assume nothing. Your students
come from widely varying backgrounds, many from schools with little or
no scientific equipment. They need instruction in its use-yes, even the
microscope-and they depend on you. This section offers hints for successful
laboratory teaching; for basic information, see "Preparing a Course,"
"The First Day of Class," and "Specific TA Concerns;"
for details about preparing lectures, see "Lecture Courses."
At the beginning of the semester:
- If your
lab is part of a lecture course, attend the lecture so you can plan
the corresponding lab work.
texts and lab manuals used in the lab and lecture. The course instructor
should schedule meetings to discuss the course and lab.
- Find out
where supplies are stored and who orders course materials.
- Give students
the laboratory and safety rules in writing and verbally, and enforce
them. If no departmental rules have been established, create necessary
- Know the
material thoroughly, including the theoretical basis and historical
background for experiments or exercises to make them relevant to students.
the content of your lab to the lecture, deciding what information to
reinforce and what to omit. Students tire quickly of frequently repeated
with and test all equipment to make certain it functions properly before
class. Know how to cope with equipment breakdowns.
all experiments and demonstrations at least once before class.
- Make certain
all necessary materials are available in the right amount.
lab notes, outlines, diagrams, and other necessary handouts.
- Write outlines,
diagrams, illustrations, etc. on the board or overhead transparencies
on time from the very first meeting; don't cancel the first lab, even
if the syllabus does not schedule an experiment (see "The First Day
of Class"). You may want to give a short (five- to ten-minute) quiz
at the beginning of labs both to inspire punctuality and to focus students'
attention immediately on the lab. With the right questions, you can also
discover how well your students are prepared for lab.
have to be more organized than you realize to teach labs.
Javier Gonzalez, Chemistry
Introduce each lab by stating what you will be doing, how it fits into
past and future work, and what the students should learn. In your short
lab lecture, you will probably do the following:
the day's project, orally and/or on the board.
the task, perhaps by demonstrating samples you or former students have
prepared. To heighten students' interest and help them remember, point
out intriguing pertinent facts: for instance, during a Biology 204 lecture
on fungi, the professor mentioned that a university administrator had
died from eating a poisonous mushroom he had misidentified on Grounds.
information students need to complete the lab activity. Prepare a handout,
especially if you use drawings or diagrams, allowing room for students
to add necessary details. Handouts help first- and second-year students
learn to take notes and reduce the amount of time spent lecturing.
materials to be used.
the lecture, you can remind yourself to invite students' questions by
writing "Questions" in colored ink at appropriate transition
spots in your notes. To promote students' thinking and verify understanding,
write appropriate questions into your lecture. If your students are not
accustomed to questions during a lecture, they may not answer until they
become more familiar with this "new" method. Begin with who,
what, when, where questions and progress to why questions. By the end
of the semester, you will have a more lively class where actual learning-not
just memorization-takes place.
observational questions which guide students' thoughts to the right
answer. In the end, the students have reasonably concluded the answers
themselves, raising their confidence and enticing their minds to future
Brian Silliman, Environmental Sciences
students' work. As students do their lab work, make yourself available.
While building rapport and encouraging students, you can easily ask probing
questions and correct faulty procedures. Call students by their names,
using a seating chart at first if necessary. Move throughout the lab,
watching for signs of students having difficulty: frustrated noises, confused
expressions, flipping of text or lab manual pages. When individuals or
groups have problems, inquire first: "What did you do first?"
"When did you first have trouble?" "How else could you
solve this dilemma?" Resist deciphering the problem for students;
help them figure it out instead (see "Academic Difficulties").
the entire class to make general remarks only when you find many students
in the same predicament. When you do work with the class as a whole, get
all students' attention before giving additional instructions. To explain
experiment procedures, use the materials to show students directly rather
than giving verbal instructions which may be confusing. Rephrase a student's
question before answering so that everyone can hear it. Not only does
this technique involve the whole class, it gives you a few moments to
consider your response.
Finish the lab by reviewing what students should have learned and, if
appropriate, previewing the work for the next class. Discuss any problematic
parts of the lab so that the lesson plan can be adjusted for next year,
a teacher to be more creative than is possible during lecture. For instance,
to illustrate the principles of optimal foraging for resources, I co-designed
an exercise called Darwinopoly: students actively foraged for candy
throughout the corridors of Gilmer Hall. They found that even humans
exhibit a variety of foraging strategies which conform to the predictions
aids vary your presentation, help clarify the direction of your talk,
and assist students who best learn visually: consider using the blackboard,
overhead projector, slides, films, computer, video, and handouts. By following
a few simple tips, even a novice lecturer can appear masterful:
- Plan and
prepare your use of visual aids ahead of time, and consider using color
to highlight important areas or ideas. Before class, make sure your
presentation is large and legible by checking from the back of the room;
remove any furniture or equipment that could distract students.
- If you
use Power Point (or another presentation program) or write the outline
or key information on the board or overhead transparency before class,
you can refer or add to it as you speak. Computer programs allow you
to keep your outlines for easy updating and changing. If you use these,
however, be sure that their presence does not lead to such a speedy
presentation that students cannot absorb material or take adequate notes.
movies, and videotapes are forceful tools if you actively teach with
them rather than using them as fillers. To prepare, preview programs
and verify that slides are available and in the correct order. When
using videotape, decide when you will pause and what questions or comments
you will use. Tell students why you're showing the program and preview
important points with them. Ask students to perform pertinent tasks
during and after the presentation. For instance, can they find the main
points or the bias of the documentary? Or, how are various geological
at the front of the room and use a pointer, if necessary, to keep students'
attention and to observe how well they are following.
- At the
end of the presentation, review quickly, emphasizing important points.
the classroom and the lab I begin with the assumption that all students
have some special talent, and I concern myself with trying to discern
and foster it. Regardless of the course level, I expect students to
have opinions, to think and learn independently, and to take an active
role in defining their work.