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:

Objective

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?

Diagram

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.

Data

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).

Method/Analysis

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.

Calculations

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.

Graphs

Whenever appropriate, present the data and/or results in graphical form. Axes need to be labeled with the proper units.

Discussion

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.

GEOL4714/5714 home | C. H. Jones | CIRES | Dept. of Geological Sciences | Univ. of Colorado at Boulder

Last modified at Tuesday, August 23, 2016 12:29 PM