Laboratory Report Guidelines
All parts of the report should be neat, legible, and well organized. Sections of a report should be in the order below and should be clearly labeled. Figures or tables should be referenced from the main text and not merely scattered about through a jumble of later pages; it is best if the figures are numbered for easy reference. Be sure that elements of a model or structure are uniquely described: saying something about "layer 1" may be vague if you've run 8 inversions with varying numbers of layers. Labeling structures or models can help. Any figures, equations, or information from outside of the lab (e.g., values of seismic velocity from a reference, figures from the internet) must be properly cited.
A good report should generally include the following sections:
- State briefly the main purpose of the experiment.
Indicate the scale of the problem being addressed and the kinds of materials
that are plausibly targets. If there was a hypothesis being investigated, lay
it out here. Descriptions like "gather seismic data" are inadequate and will be marked down; echoing the purpose put at the beginning of the lab instructions is also not appropriate (I have left those deliberately vague and more focused on the techniques we are exploring than the specific application). What do you hope to learn about the earth from your experiment?
- As in Field Notebook, only
neater (i.e., not a scanned version of field notes). The diagram should show geometrically how equipment was laid out,
with a scale and, where appropriate, north arrows. Sometimes multiple diagrams
are needed (e.g., a simple cartoon of a resistivity profile might accompany
a location diagram showing where several profiles were acquired). This is usually where you identify specific points, e.g., numbered flags, numbered geophones, etc.
- Location Map
- As in Field Notebook, only neater.
Must have latitude and longitude; many times I provide a reference topographic map on the website that you can download and use. In general, using a topo map is best. Google maps, while handy, are often poorer because they usually lack a scale and frequently lack latitude and longitude; if you use them, be sure to remedy this deficiency. Google Earth images are often even worse because they are not true scale maps but attempts to mimic the view from a specific spot.
- Identification of Apparatus
- As in Field Notebook.
- As in Field Notebook, only neater
(often convenient to put it into a spreadsheet). Please pay attention to the proper number of significant digits, especially in field measurements as well as final values at the end of any computations (keeping extra digits in intermediate calculations is more forgivable).
- Describe how you have analyzed or reduced the data. If using software, indicate what version of software (and its name) and briefly describe how it is used. It is not acceptable to simply state that you used the software unless there is only one possible way to use it (the only common examples these days are small Unix utilities). So if you use Matlab, state the version and what you did in it (in some cases, copying the commands used might be appropriate). If using Excel, provide the equation(s) used in making calculations, noting which columns are used for input or output. If using software provided with the text, indicate the sequence of steps used in analysis and what criteria you used for deciding that you had reached an acceptable model for your data. Again, the idea is to provide enough information that somebody else could reproduce what you did. If appropriate, accompany this description with a table of your results and any appropriate intermediate values. It may be more obvious if you replace the name of the software with "Swiss Army knife." If I told you I repaired your computer with a Swiss Army knife, would you be able to fix it yourself? No? Then why do you expect somebody to know how you fit data if you just used some named software? Tell what steps you followed and what basis you had for moving on to the next step.
- Give any mathematical formulas that you intend to use, and provide one
sample calculation for each formula by substituting numerical values with the
proper units for a particular case. Do not otherwise show numerical details,
but provide a concise summary of the results of the calculations to a proper
number of significant figures.
- Whenever appropriate, present the data and/or results in graphical form.
Axes need to be labeled with the proper units.
- This section should contain a concise summary and evaluation of the experiment. Each of the following items need take only one or two sentences. (a) Identify the principal results of your measurements and calculations. One or two numerical values may be incorporated within a sentence, but any more extensive tabular or graphical results should simply be referred to where they appear in previous portions of the report. (b) Comment on the precision of your results, indicate approximate limits or error, and mention briefly the principal factors contributing to the error. (c) Compare your results to expectations. State the source, including page, from which an expected value is taken (e.g., Table x.x of seismic velocities from Burger, p. xx). Lack of agreement between your result and an accepted value does not necessarily represent an error on your part; your sample may have been different or your measurements may have been made under different conditions.
Sections of a report should have above sections in order. Figures or tables
should be referenced from the main text and not merely scattered about through
a jumble of later pages; it is best if the figures are numbered for easy reference. Be sure that elements of a model or structure are
uniquely described: saying something about "layer 1" may be vague
if you've run 8 inversions with varying numbers of layers. Labelling structures
or models can help.
Appropriate use of significant figures is something you should have seen and dealt with in other classes. You can get marked down for using an inappropriate number of digits. Just because your calculator can churn out 12 digits doesn't mean that should be in your report! Significant digits originate with the level of accuracy of a starting measurement. If you are pacing distances, it is unlikely you will know distances to the millimeter; listing distances to the decimeter or possibly centimeter would be as far as you should go. Similarly, you cannot know gravity to the microgal if your readings are only to the tenth of a milligal. There is somewhat greater latitude in reporting the characteristics of a model used to fit data, but again unreasonable numbers of digits should be avoided.
Please send mail if
you encounter any problems or have suggestions.
GEOL4714/5714 home | C.
H. Jones | CIRES
| Dept. of Geological
Sciences | Univ. of Colorado
Last modified at
Tuesday, August 23, 2016 12:29 PM