Lab Writeup

General Physics Lab Write-Up

I assign the labs in general for the following reasons:

1. For you to learn how to do science labs.

2. For you to learn how to write up science labs.

3. For you to learn how to use computers in the aid of scientific research.

4. For you to learn first-hand about the concepts of mechanics, in this case kinematics: for you to see for yourself that the acceleration is indeed the slope of the velocity versus time.

The purpose of you taking the lab is all of the above, but the individual purpose of each experiment is to discover something, in most cases to measure something.

Let me give you a simple example: When you are doing academic research, and you write up the results for a scientific paper to be published in journal, you do not include the motivating reasons of why you are doing the research in the first place: "I am doing this research because I want to advance my career, make more money, and make my mark on the scientific community", you only talk about the purpose of the experiment you are doing: "We are trying to measure the effect of rainfall on people's happiness".

I want you to treat lab write-ups as scientific papers. Yes, I want you to learn the concepts, but what are you trying to determine by running the experiment? The purpose is "what you are trying to measure" rather than "what I am trying to teach you", and indeed they are different things. In the second lab, you are trying to measure the acceleration due to gravity. But I am not still trying to teach you that - I assume you already know it is 9.8 m/s^2. I am trying to teach you to think about how to carry out a reasonable experiment and how to do straight-line fit analysis to determine an experimental measurement.

While you work in groups on the experiments, all of the analysis and writing (for individual labs) should be done on your own. Of course, you should verify that you are getting the same answers as others in your group. Copying a lab or portion of a lab, even from your partner, is a violation of the honor code.

This is a link to details of what is below. These details have been discussed in lab.
This is the grading rubric for labs.

Please Note: You should always do enough data analysis - look at your data - before you leave lab to make sure you have what you need, and to make sure you did the experiment correctly. Once you have left lab, if you find you made a mistake collecting data, and what you have does not allow you to fulfill the purpose, then you must make arrangements with me to come back and re-take your data. Otherwise, incorrect experimental procedure will affect your lab grade.

The lab write-up will usually include:

name, partners' names, date
title of experiment
purpose
- What is the purpose of the experiment itself. The purpose of the lab is not "to better learn". Well, the purpose of everything you do here is to learn, but what goes here is WHAT IS THE PURPOSE OF THE LABORATORY EXPERIMENT? What are you trying to measure? Do not put procedure in the purpose.
apparatus schematics and method ONLY if they differ from the handout, otherwise just include a link to the procedure in the lab manual
data in tabulated form
- You do not need correct significant digits in your EXCEL sheet as long as you have them correctly in the analysis/conclusion sections. COPY all pertinent EXCEL tables to your lab writeup (only exception is if raw data table is excessively long).
plots (if any)
- Data and plots should be input/done/calculated in the Excel spreadsheet. For informal reports, print them out and glue or tape them into your notebook. For formal labs you should COPY and PASTE relevant plots to your write-up document.
Tables and plots should be properly labeled (axes, columns, titles, captions with appropriate units); be sure it is clear what the table or plot is showing. Tables and plots should have titles or captions that explain what they represent.
results/error analysis (use correct significant digits)
- Your analysis section should include a discussion of error. What are the possible sources of error? Are they random or systematic? Do you really think they are significant? If so, HOW DO YOU THINK THAT ERROR WOULD AFFECT YOUR DATA - that is, would it explain any discrepancies you saw?
- If you did a straight-line fit, in your analysis you must always discuss both the slope and y-intercept to 90% confidence. What is the physical meaning of each?
conclusions
- Your conclusion must address the purpose. Did you fulfill the purpose? You must restate your pertinent results in the conclusion. e.g., even if you had it in another section, state your predicted range vs. your actual range, and briefly state how they compared. Be sure to use ninety percent confidence intervals and be sure to have correct significant digits.
Please be sure to answer any additional questions posed in the online lab manual (as questions) in either the conclusions or an additional section at the end: whichever is most fitting.

This is a trivial example from the first "lab" in physics 105.

PROOFREAD YOUR DOCUMENT. This is meant to be a well-written, concise document. You should consider it no different than a paper you have written for a humanities class.

In a scientific paper, use verb tenses (past, present, and future) exactly as you would in ordinary writing. Use the past tense to report what happened in the past: what you did, what someone reported, what happened in an experiment, and so on. Use the present tense to express general truths, such as conclusions (drawn by you or by others) and atemporal facts (including information about what the paper does or covers). Reserve the future tense for perspectives: what you will do in the coming months or years. Typically, most of your sentences will be in the past tense, some will be in the present tense, and very few, if any, will be in the future tense.

For more details on writing a clear, concise scientific document, see http://www.nature.com/scitable/topicpage/effective-writing-13815989