Lab Report Format

It is essential that students be able to express their ideas and defend their arguments with clarity, detail and subtlety.
Similarly, it is important that they can read and critique the ideas and arguments of others in like manner.
The creation of lab reports assists in this endeavor.

Lab reports for my PH106 Science of Sound, ET151 Circuits 1, ET152 Circuits 2, ET161 Linear Electronics, and ET262 Operational Ampifiers courses use the same format. Unless otherwise specified, all lab exercises require a write-up. All reports should be neat and legible. Standard technical writing style is expected along with proper grammar and spelling. This means that active voice, first person, personal pronouns, and the like should be avoided. For example, don't write "I set the power supply to 6 volts". Instead use "The power supply was set to 6 volts". Reports are an individual endeavor. Although it is perfectly fine to discuss your data and experimental results with your lab partner, the creation of the report itself is an individual exercise. Plagiarism will not be tolerated. A report should conform to the following outline, in the order given:


1) Objective /
Hypothesis.  These are statements regarding the items, relationships, characteristics, etc. that you are investigating in this particular exercise. This is the first part that you write. Indeed, it can be written before you even step foot into the lab. An hypothesis tends to be narrow and focused, but not so focused that it only applies to this particular exercise. Examples might be "The speed of sound in air increases as the air temperature rises" or "The voltage across a given resistance is directly proportional to the current through it". This section tends to be fairly short.

2) Conclusion. Address the hypothesis: was it verified? These are concise statements of fact regarding the circuit action(s) under investigation. Make sure that you have moved from the specific lab situation to the general case. If all works well, these should match nicely with your Objective/Hypothesis section. Under no circumstances should you reach a conclusion that is not supported by your data, even if that conclusion is stated in the text or in lecture. What matters here is what you did and your analysis of it. If there is a discrepancy between your results and theory, state the discrepancy and don't ignore your results. The Conclusion is the final section that you write. It addresses the Objective and is supported by the Discussion. Think of it as an Executive Summary.

3) Discussion (AKA Analysis). Reduce and analyze your data. Explain circuit action or concepts under investigation. Relate theoretical results to the lab results. Don't just state what happened, but comment on why and its implications. Derive your conclusions from this section. The Discussion is not a rewording of the procedure, however, any deviations from the procedure as given by the lab manual must be noted in this section. Otherwise the procedure used is assumed to be the same as in the lab manual. The Discussion is the penultimate part that you write and tends to be the longest section. When performing your analysis, always keep in mind that you should be trying to afirm the null hypothesis. The null hypothesis is, in essence, the inverse of the stated hypothesis. You can think of it as the default situation. Using the first example hypothesis above, the null would be "The speed of sound in air is not dependent on air temperature". In your data tables, you'd be looking to see if the null is true, i.e., that there is no relationship between speed and temperature. In this case, if your data were correct, they would indicate an increase in speed as temperature rose, so the null is not true, and therefor your hypothesis is a valid candidate for describing reality. Having this mindset helps you to avoid cherry picking the data, that is, only seeing the things that confirm what you want and ignoring the rest. Cherry picking is a form of observer bias, is intellectually dishonest, and any good investigation needs to avoid it.

4) Final Data Sheet. Include all derived and calculated data. Make sure that you include percent deviations for each theory/measurement pair. Use Percent Deviation = (Measured-Theory)/Theory * 100, and include the sign. Include the model and serial numbers of all test equipment. Along with the graphs, this is the second part of the report that you write. Until this section is completed, it is not possible to complete an analysis and write the Discussion section.

5) Graphs, Answers to questions at the end of the exercise, Other. All graphs must be properly titled, created using appropriate scales, and identified with labels. It is suggested that graphs be created with a plotting program or a spreadsheet. Alternately, graphs may be created manually but must be drawn using either a straight edge or a french curve (depending on the type of graph) on appropriate graph paper. You can get details on graphing here.

You can see an example lab report here. If you're wondering why the order of presentation is not the same as the order in which the sections are performed and written, it's because reports commonly present findings in the following manner: "Here's what I set out to do. Here's what I discovered. Here's the details of how I got there."

Make sure that you leave sufficient space in the margins and between sections for my comments. 1.5 line spacing is fine. Multi-page reports should printed single-sided and must be stapled in the upper left corner. Paper clips, fold-overs, bits of hook-up wire, etc. are not acceptable. Reports are due no later than the start of the next lab period following the date performed. Late reports are reduced by one letter grade for the first half week late and two letter grades for the second half week. Reports are not acceptable beyond one week late. Below is the grading standard.

Grade of A: The report meets or exceeds the assignment particulars. The report is neat and professional in appearance, including proper spelling and syntax. The analysis is at the appropriate level and of sufficient detail. Data tables and graphical data are presented in a clear and concise manner. Problem solutions are sufficiently detailed and correct. Diagrams have a professional appearance.

Grade of B: The report is close to the ideal although it suffers from some minor drawbacks which may include some spelling or grammatical errors, analyses which may lack sufficient detail, minor omissions in tabular or graphical data, and the like. In general, the report is solid but could use refinement or tightening.

Grade of C: The report is serviceable and conveys the major ideas although it may be vague in spots. Spelling and grammatical errors may be more numerous than those found in a grade A or B report. Some gaps in data or omissions in explanations may be seen.

Grade of D: Besides typical spelling and grammatical errors, the report suffers from logical errors such as conclusions which are not supported by laboratory data. Analyses tend to be vague and possibly misleading. Graphs and diagrams are drawn in an unclear manner.

Grade of F: The report exhibits many of the following deficiencies: Excessive spelling and grammatical errors, missing sections such as graphs, tables, and analyses, blatantly incorrect analyses, wayward or incomprehensible data, problem solutions tend to be incorrect or missing, and graphical data or diagrams are presented in a shoddy manner.

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