These labs are very different from the traditional.

A laboratory can fulfill a wide variety of purposes.  Traditional labs often teach students to follow protocols or are intended to demonstrate that the theory taught in lecture "actually works".  Our labs in 121-122 have a different goal.

• The goal of the SCL is to help the student learn
  • How to design an experiment to answer a question;
  • How the design can affect the quality of an experimental result;
  • That each measurement tells a range of possible answers and how to determine that range;
  • How to refine their experiment in order to improve it.

     

• The lab is set up to mimic the actual process of scientific experimentation so
  • They may have to do the experiment before they have "learned the answer";
  • They have to present their work to peers; and
  • They have to learn to give and take constructive criticism.

     

Since the lab is set up to create a model of a "scientific community" for the students, we refer to them as Scientific Community Labs (SCL).

The SCL is not structured as following a protocol.

The SCL lab is structured to help the students get the experience of learning something through a scientific experiment.  Here's the structure:

1. Students work in groups of 4 and construct a single lab report among them.
2. The have two 2-hour periods to complete a single lab.
3. In the first period, they design their experiment, construct the apparatus, and take their data.
4. In the second period, they analyze it and create a presentation for the entire class of their results.
5. In the last hour of the second period there should be a presentation by each group and a discussion.
6. The last 10 minutes should be reserved to have the students finalize their report. 

Writing the report

Each group should assign one member to write each of the four parts of the report -- and they should rotate those roles through the term. The roles are:

• Describing the design
• Presenting the data
• Analyzing the data
• Evaluation the experiment after the whole-class discussion.

   

What's the TA's job in an SCL?

The TA is critical in "setting the frame" and helping the students understand what it is they are trying to accomplish.  You have a number of tasks.

1. Focus them on the activity, not on the answer.

   Since the students are very concerned about their grades they tend to focus on "how to get the answer the grader wants."  We want them to focus not on the answer but on the process of doing science. 

2. Grade them on the quality of their process, not on the answer they get.

   You should make it clear to the students that their grade on their report will be based NOT on whether they get the "right answer" but on whether they have done a well-thought out and careful experiment.  In your grading you should encourage "good tries" that did not work but that they could not have been expected to know would not work. 
3. Keep their attention on how the experiment is getting the answer to the question.

   Your goal is to have each student engaged with creating and doing their experiment with their group.  Students (and faculty!) can easily get trapped in the technicality of an experiment they have designed without sufficient thought.  If you see them on a dramatically wrong track, the following questions can help.

   • What are you doing?
   • Why are you doing it?
   • If you succeed, how will you get the answer to the question you are investigating?
4. Keep an eye on the time so that there is enough time (45-60 minutes) for presentations and discussion.

   The students can easily work on their experiment for the full four hour block.  Make an effort to keep them on track and moving along so that there is time to prepare and deliver the presentation and have a discussion.

5. Help them participate in a spirited, interactive, and productive discussion.

   Many of the students in the class don't know how to have a scientific discussion -- how to focus on the argument and not make criticisms personal.  Many are reluctant to say anything for fear of saying something wrong.  It is important for you to create an environment in which they are comfortable discussing how one might improve each group's experiment.  This is easier said than done.  If you provide too much guidance, they will rely too much on you.  If you provide not enough, they might hang back and not contribute enough.  Finding the right balance is tricky and can depend on what students you have.  Your goal is to have them excited and engaged in the discussion and for you to disappear into the woodwork as an observer, not as the leader.

Your grading pattern is very important.

1. Your grading should give the students feedback on what you want them to do.
2. Don't "ramp up" your grading right away.  If they improve let them see it in improved grades.
3. Grades should be given for good thinking and presentation, not answers.      
4. Let them know what the components of your grading are for.     

    Here's a good pattern:

          -- Design and thoughtfulness.  (5 pts -- for group report)

Did they do a careful and thoughtful job in creating their experiment, and was this thought reflected in the journal?

          -- Clarity and completeness. (5 pts -- for group report)

Did they explain your experiment so that someone could reproduce it?

          -- Persuasiveness.  (5 pts -- for group report)

What conclusions did they draw from their data, and were thet able to back up these conclusions with this data, in a convincing way?

          -- Participation. (5 pts  -- for individual)

This is not from the report (and NOT for participation in the design and carrying out of the lab) but from the end-of-lab discussion ONLY.  These points are for actively participating in the presentation and delivery (max 2) and for asking  useful questions or making comments that were valuable to the other teams’ writeups of their evaluations (max 3).

121-122 TA Guidlines (Redish)