This volume provides a guide for lab instructors to accompany the NMSU ASTR 110 lab manual. It describes the overall philosophy of the labs and provides some guidelines and hints for how to make the labs most effective for the students. It also describes the necessary information to make sure that the labs are set up and prepared for properly.
The basic philosophy of these revised labs is to maximize the amount that the students experiment during the labs, and to minimize the amount the lab instructor lectures the students. Students get enough lectures during classtime; the labs provide an ideal opportunity for the students to play around with various equipment and concepts in an effort to learn by expermentation. The instructor should make every effort to keep the amount of introduction at the beginning of the lab session to a minimum; it is important to make sure everyone understands what the lab is about, but the goal is to have students figure out concepts by experimenting with them, not by being told about them.
There are sometimes techniques in the labs which some or all of the students may not be familiar with, e.g., scientific notation, unit conversion, etc. Rather than giving a lecture about these beforehand, it is probably better to let things come up and discuss them as they do; this avoids lecturing to students who already know certain things, doesn't turn off the students who aren't familiar with these ideas or find them boring to hear about, and makes it clear that we'll only discuss stuff which is relevant to what we are doing. The ASTR 110 labs are not the appropriate place to give remedial math lectures; we want students to explore astronomical concepts and realize for themselves what is required to do this.
In general, all attempts should be made to make the labs relatively fun for the students. The joy of scientific experimentation is just playing around with equipment and ideas. There is no real need for students to get the right answer; overall, in science, we never know what the right answer is in advance anyway. It does a disservice to the students to have them try to perform the labs in order to get some predetermined answer; this is not the way science works.
The inevitable problem with this sort of approach (i.e., don't worry about the answer) is that students are preoccupied with their grades, and everyone feels that the grade depends on getting the correct answer. For this reason, I advocate adopting a relatively lenient approach towards grading, and the instructor must award points for well thought-out explanations for results, even if the results do not come out as the instructor would have liked.
In fact, experience has shown that measurements by the students in the lab are often made quite sloppily, so it is fairly common for results not to come out very well. Instead of making students feel that have done something wrong, the instructor might take advantage of this opportunity to show that measurements are not always trivial and measurements with their corresponding results and interpretations are not always correct. An underlying theme through the labs is the concept of measurement error and repeatability, and at all stages, students should be encouraged to estimate errors by repeating measurements, comparing with other groups, etc.