Teaching Assistant Handbook
Compiled by Prof. Gary E. Ford, September 1999
Revised by Prof. Richard R. Spencer, July, 2000
Students in many lab courses are required to prepare and maintain laboratory notebooks. TAs are expected to guide students in the preparation of these notebooks and to grade them. This section provides some guidelines for accomplishing these tasks.
A complete record of a student's work in the laboratory is to be maintained in an engineering notebook. Before explaining what is to be recorded in the notebook it is necessary to differentiate between a notebook and an engineering report. The notebook is a working document used to record all of the details of the work done in the laboratory. In an industrial setting, the notebook is primarily a record for your own use, although if you are working in a project group, other group members may refer to it occasionally. It has no rigid format, although some guidelines should be followed and are presented below. It should be neat and readable, although it is often written in outline form as a collection of short phrases instead of complete sentences. The important objective is to provide yourself with enough information to be able to recall exactly what work you have done on your project.
The engineering report is a formal document written to summarize the work completed on a project. It is often written at the conclusion of the project, but in the case of long projects, interim reports or progress reports are also required. This document is primarily intended for your supervisor, the project leader, or for other project managers. For example, for an electronic circuit, a description of the design, implementation, test, evaluation and performance would be included, but the day-to-day details would be left out.
In many courses, students are required to maintain an engineering notebook, but are not be asked to prepare any engineering reports. They must have their notebooks open on their lab benches at all times, ready for use in recording all of their measurements and observations. A problem with many laboratory courses is that the grading standards applied to the laboratory notebooks are so severe that students feel that they are required instead to write formal engineering reports. They begin to record their observations and measurements in the lab on scratch paper and then go home and edit the information before recording it very carefully in their notebooks. This is unfortunate because they then do not learn how to properly maintain a working notebook and they also view this as such a painful process that they may avoid it altogether when they begin working in industry. As a TA you should do your best to avoid this problem and help the students prepare and maintain a working notebook.
A lab notebook is a diary of activity on laboratory projects. It should be a continuous chronological account of exactly what was done, when it was done, and why. It should be complete enough that an engineer, using only the recorded material, could repeat any measurement, check any result, duplicate any set-up or even reconstruct the entire development.
A well kept notebook provides a great help to an engineer in many ways, including the following:
- As a compact, handy, orderly reference book. When you want a piece of early data, you can avoid digging through piles of stray sheets of paper on your desk or in your files by simply opening your notebook to the right page.
- As evidence of diligence. Sometimes lack of progress is not due to lack of effort. But unless you can point to the record of your efforts in your notebook, wrong conclusions may be drawn.
- In avoiding repetition. Lost, misplaced, or forgotten data often must be taken all over again. You won't have to go through this wasted effort if you keep good records.
- As a record of priority. One of your sources of recognition is the designs you produce. Unless your notebook clearly shows the date of conception, the full description of the design, and the record of your subsequent efforts at reduction to practice, your position is weak and you may lose credit for what is really yours. This record is especially important when patents are involved. Whenever you have an idea that may be patentable, you should have the appropriate pages in your lab notebook witnessed (read, signed as having been read and understood, and dated) by at least one of your co-workers.
- As a guide to your thinking. The ready accessibility of all data concerning your job facilitates review, helps you see where you are; what's been tried and what hasn't, points the way by revealing the best solutions to date. Even the time spent making entries is not wasted, as it forces careful consideration of your work and this often reveals errors or points overlooked.
As mentioned above, there is no rigid format for writing a lab notebook,
but it is easier to follow later if a standard format is adopted.
Again, the most important thing is to include all of the information
that allows the writer or another engineer to understand all the work
that has been done on the project and to be able to repeat any of the
work to verify the results, if that is needed at a later date. The
notebook must be neat and well-enough organized that needed information
can be found when it is wanted. With these guidelines in mind, here is
a general outline for documenting a lab project (it is assumed in the
following that the project involves circuit design, but it applies
equally to other projects):
- Objectives. Briefly describe the objectives of the project: the circuit to be designed, implemented, and tested, and its intended use.
- Specifications. Describe the technical and performance specifications that must be met by the circuit or system that is to be designed. It is perfectly acceptable to refer to published documents here rather than repeating them if they are lengthy. It is, however, wise to record whatever data you need while you are working.
- Design methodology. Describe the procedures you followed in designing the circuit. Explain design decisions and write down all equations used and calculations made. Sketch rough schematics of the circuits, with nodes labeled for SPICE analysis. Include SPICE input commands and graphical outputs. It is perfectly acceptable to paste or tape into your notebook copies of printouts, photographs, plots and other items.
- Implementation. Draw detailed schematics of all circuits built. These should be very complete, using functional schematics of integrated circuits instead of the pin-out schematics given in the data books. Label each terminal with its function were appropriate and give the pin number to help with troubleshooting. Measure the values of resistors and capacitors when they are critical to performance.
- Troubleshooting. Describe the procedures followed in troubleshooting the circuits. Don't simply write "we tried it and it worked," but instead describe the test configuration, test signals applied, and measurements taken. Discuss how you concluded that it was working correctly. If it did not work properly, explain the problem and how you solved it. Discuss any redesign that was required. Keep a list of the equipment used. Since this list will not change often, list your equipment in the front of your notebook, and then list any changes as they occur. Give the manufacturer, model number, and serial number.
- Test and evaluation. Explain the test set-ups and the measurements taken. Provide clear, organized graphs, performance tables and observations. Graphs should be drawn as the measurements are taken. In this way, you can visually detect anomalous values and quickly check these measurements to verify their accuracy. Explain what the data means by explaining how it agrees with the corresponding mathematical model. Your report should be more than just a collection of tables, graphs, and equations. Your interpretations and explanations of this material is the most important part of the report. If you realize that your data is not in agreement with theory, then explain why you think it is in error and what data you expected to record.
- Conclusion. Summarize the work accomplished. Discuss any critical design factors. Compare the actual performance with the theoretical performance. Discuss alternative approaches.
As a TA you should strongly suggest that students use an 8 1/2-inch by 11-inch spiral ring gridded paper lab book to record their observations. The large size allows them to insert copies of application notes, and SPICE inputs and graphical output. The gridded paper makes it easier to draw schematics, graphs, and tables.
It is not necessary to record all information while working in the lab. Items 1,2,7 and parts of 3 and 4 above can be entered at home when students are preparing for the lab. This is similar to the common practice in industry, where engineers work out their paper designs at their desk, and then move to their lab benches to do the experimental work.
Other guidelines regarding a notebook include the following:
- All entries should be clearly legible, preferably in ink. The entries MUST be in ink if you want to use the notebook to help support a patent.
- The first entry should be dated at the beginning of each work period, whether in lab or outside of lab. Many notebooks and companines require you to sign and date EACH page.
- Make entries in chronological order. Do NOT leave blank pages (At the very least, this leaves the impression that you want to be able to go back and add something so that it will appear to have been your idea or will appear to have been done sooner than it was. Either way, the impression is bad, and the actual practice is unethical at best and illegal at worst). If you are working on more than one project at a time, just interleave them in the notebook. You can put at the bottom of each page the page number of the next page relevant to that project (i.e., at the bottom of page 12, your book may say "go to page 34" if pages 13-33 do not apply to the project on page 12). You may also be allowed to keep different notebooks, one for each project.
- Cross out, but do not erase superseded entries. Leave them legible. NEVER tear out or obliterate pages.
- Include adequate topic headings to facilitate later search and indexing. Use explanatory text freely.
- Show schematics with element values of all tested circuits. Show block diagrams of test setups. Include instrument numbers. Indicate clearly where readings comprising recorded data were observed.
- Adequately label and reference all curves and coordinate axes. Graph sheets should be securely pasted in place.
- Intermediate calculations, if of no interest in themselves, may be made on scratch paper, but all premises and factors involved in the calculations and all results should be recorded.
- Many engineers get in the habit of recording almost everything in their lab notebooks, which is not a bad idea. Notes on telephone conversations with vendors and customers, lists of things that need to be done, ideas that are only tangentially related to the present project, all of these can be put in the lab notebook. When it used in that way, it becomes a nice chronological record of your work.
- Finally, a good table of contents is useful. Some lab notebooks have one at the front, if yours does not, you CAN label the top of the first couple of pages as a Table of Contents (label in ink) and then fill it in as you use the book.