Writing A Good Lab Report

As a student double-majoring in chemistry and biology, I’ve written my fair share of lab reports. They’re not always fun, and they’re not usually easy. However, lab reports are more than just a way of getting points- they’re your opportunity to explain a concept to a person knowledgeable about the concepts you’re learning and get feedback on your understanding. They also demonstrate theoretical and practical knowledge of laboratory methods in your field- something which employers and admissions committees (grad school, med school, or otherwise) look for. Finally, they help you hone two skills that I guarantee you will need no matter where you end up working after college- information literacy (the ability to find, evaluate, and use sources while giving credit to the author(s) of the sources) and writing.

You aren’t a good scientist if you can’t describe your research to other people. You could be the most brilliant person alive, but if your ideas come out looking unpolished, nobody is going to publish them. The good news is that writing, like pretty much everything else in science, is an acquired skill! You can get better at it, and you should get better at it. This involves reading papers to see how other people do it, but it most importantly involves practicing.

One unexpected place you will obtain writing skills is in your humanities classes. Where did I learn how to evaluate sources for my papers? My freshman level writing class. Where did I learn how to effectively paraphrase? Studies in Women’s Literature. Did I learn the skills necessary to interpret difficult passages filled with technical words and phrases in Organic Chemistry? Yeah, partially, but I was building on a skillset obtained from New Testament: Acts, Epistles, and Revelation, a Catholicism class I took freshman year. Humanities classes are full of opportunities for you to grow as a writer, so don’t waste them.

One resource which I will plug nonstop to you throughout this entire post is your college/university Writing Center. A lot of STEM majors are hesitant to use their services for science-related papers because of the idea that only English majors work there, so it might require a lot of explaining of the science. Heads up: your lab report should be explaining the science with such clarity that anyone should be able to understand it, regardless of their major. Also, most professors mark people down on lab reports for poor grammar, which Writing Center tutors will gladly help you with. Go in with the idea that you will learn something, and you always will. Honest feedback is more important than feeling smart. One final disclaimer: you cannot expect to put minimal effort into a project and obtain stellar results.

Good lab reports have these common sections:

In the order they appear in your paper:

1.      Abstract

2.      Introduction

3.      Materials & Methods

4.      Results

5.      Conclusion/Discussion

6.      References

In the order that is easiest to write them:

1.      Materials & Methods

2.      Results

3.      Introduction & References (Write these two together)

4.      Conclusion/Discussion & References (You may end up using some references in your conclusion; CITE THEM!)

5.      Abstract (ALWAYS write the abstract last)

Keeping a Record in a Laboratory Notebook

First, make sure you are keeping a detailed, professional record of everything you do in lab in a laboratory notebook (consult your professor on how to do this). This record should include everything you did, every material or organism you used, every piece of equipment you used, every observation you made, and every bit of data you collected. In some disciplines (i.e. ecology, environmental science) you may collect samples out in the field- you must provide detailed information about the location, weather conditions, and time of day in which you sampled. GPS coordinates are sufficient for a location.

You should also write, at the beginning of every experiment, a purpose statement which explains why you are carrying out this experiment. If you record everything in your own words, it will help you out immensely when the time comes to write your report.

Take pictures of the experiment, but don’t use pictures as a substitute for describing what you see and do using words.

Writing the Materials & Methods Section

If you wrote down a detailed procedure in your laboratory notebook in your own words, you may copy it over into your materials and methods section. If you followed a published procedure, you need to cite the procedure you are using. We’ll talk about references in a minute. If you took pictures of materials, samples, or equipment that you used, you can include those in this section.

Avoid first person. Instead of saying “I boiled water,” say “The water was boiled.” This paper is about your experiment, not you.

Writing the Results Section

This is the section where you put observations, data collected, graphs, and pictures of results. This is fairly easy if you kept a good record of everything you did in lab, because you’ll have all of your observations written out, in your own words, on the page in front of you. This section is only for stating your results; do not interpret or analyze them here. Sometimes there are calculations needed to obtain or support your results. Some professors require a separate calculations section, some do not. Ask your professor.

Even if you have a picture of your results, describe them in words. Even if you have a table full of data, describe it in words. Even if you have a graph, describe it in words. If you went into science because you thought you wouldn’t have to write, you were wrong.

Writing the Introduction

This section should describe the theory behind your experiment in clear, concise language. “Theory” is a broad term thrown around by scientists, but it basically means answering the questions:

•        What concepts are we trying to illustrate here?

•        What does this particular method involve?

•        Why is each step of the method you are using important for a successful experiment?

•        Is there anything important the reader needs to know about the chemicals/specimens/samples being used?

•        What research is currently being done on the concepts illustrated here?

•        Are there any industrial, medical, or food applications of these concepts/samples/chemicals/organisms?

In the introduction, you also need a purpose statement which briefly describes what the goal of your experiment is.  Most scientific papers put this purpose statement at the end of the introduction. This basically serves the same function as a thesis statement in a regular paper, but it is not the same thing as a thesis statement.  You do not include any of your results or discussions in this statement, but you very briefly mention your methods.

Example: “Rainwater was collected in the woods behind Madonna University and titrated with 0.10 N NaOH to determine the acidity of rainfall in Livonia, MI.”

We do not use direct quotations in science, only paraphrased material. Even though everything in this section is paraphrased, you must have a citation for each and every paraphrase. Assume that nothing you write in your introduction is general knowledge. You need a citation to back up every single statement you make. YOU know that water boils at 100 degrees Celsius, and I know that, and YOUR PROFESSOR knows that, but did you personally discover that fact? If not, find a credible source to back yourself up. If you did make that landmark discovery, and are trying to use it in a later paper, you can totally do that! Guess what? You can cite your previous works as a source, as long as your professor is ok with it. (You still have to cite it, though). Professors will have differing requirements about what constitutes a credible source, but my rule of thumb is this: a textbook, a peer-reviewed journal article, or a website ending in .edu or .gov . CITE EVERY SINGLE SOURCE YOU USE AS YOU USE IT. Consult your professor about what format you should use. If you wait until the end to write your references page, it will not be pleasant. Trust me.

Finally, your introduction should make sense. It needs to be well-organized. To be well-organized, you need topic sentences and strong transitions from one idea to the next. You can’t just toss ideas on the page and expect your reader to follow it. Your introduction is the part of the paper which a Writing Center would be the most help with. Plenty of STEM majors suffer from an attitude of pride- they believe that writing for the sciences is just too complicated for a non-STEM major to understand, or that grammar shouldn’t matter. WRONG. If you’re writing a lab report correctly, you should be able to walk someone of any major with zero background on the subject through the theory behind your paper. If not, you are not being clear enough. Also, your professor is more likely to mark you down for a bunch of typos or plagiarism than they are for screwing up the actual experiment. Where grammar and citations are concerned, Writing Center tutors are experts. They also usually know a fair amount about evaluating sources, if you’re unsure of credibility. Don’t be too proud to get the help you need to get a good grade.

Writing the Conclusion/Discussion

This section is where you take all of the previous sections and mash them together into something meaningful. Remember your results? Start there.

•        Did your experiment work? If so, describe why the methods you used were effective. If not, suggest reasons why the methods used were ineffective. Citing outside sources is not unwelcome here, but cite them correctly!

•        Did you notice anything weird during the experiment? Try to explain it. Do some research. Has anyone else noticed this before? Can you think of any explanations? Cite any sources you use.

•        What would you suggest for future versions of this experiment? How could future students improve it?

It’s ok to admit you did something wrong! In fact, it’s encouraged. Obviously you want to be careful in the laboratory, but every failure is an opportunity to learn. The important thing is to explain what went wrong, how it impacted the experiment, and how to avoid it in the future. This proves to your professor that you learned from your mistakes.

Writing the References Section

We’ve been talking about citing things as you go, and here’s what I mean by that:

1. As soon as you find a credible source and decide to use it, create a citation for it in your reference list.
2. Determine what the in-text citation looks like for that source.
3. Paraphrase the information you want to use and attach the in-text citation to your paraphrase.
4. The paraphrase with the in-text citation goes in the text of the report, in whichever section you’re working on.
5. The citation itself goes in the reference list.

YOU CANNOT INCLUDE A SOURCE IN THE REFERENCE LIST THAT YOU DON’T CITE IT IN THE TEXT OF THE PAPER, AND YOU CAN’T CITE A SOURCE IN YOUR PAPER IF YOU DON’T INCLUDE IT IN YOUR REFERENCE LIST. To do so is plagiarism, and you could face some pretty harsh consequences. This is why it’s important to cite each source as you use it- you cover all your bases.

You need to use the citation style recommended by your professor. If they don’t care which style you use, pick APA or CSE. These are designed for use in the sciences. MLA is better suited for papers in humanities classes. Your reference page should be formatted in accordance with the style you or your professor chose. Again, consult the Writing Center about any issues you have with citations or reference pages. They do this all the time and they will be able to help.

Writing an Abstract

If you’ve ever looked through an online database for a journal article to cite for a paper, you are very familiar with the purpose of an abstract- to allow the reader to decide within 5 minutes whether or not it’s a waste of their time to read this paper. Abstracts are very short summaries of the paper. Abstracts are, above all else, concise. You should aim for 5-6 sentences:

1.      Sentence summarizing the introduction

2.      Another sentence summarizing the introduction

3.      Sentence summarizing the methods used

4.      Sentence summarizing the results obtained

5.      Sentence summarizing the conclusion reached through discussion

Lots of people have trouble writing abstracts, so feedback is your best friend here. Consult your professor on their requirements for an abstract. Bring them a sample abstract that you write ahead of the deadline and ask them for some very brief feedback. Consult the Writing Center. Again, they’re pretty up-to-snuff on writing abstracts, especially considering that abstracts are used in every discipline, not just science.

A Few Notes on Lab Reports

Verb tenses:

Introduction:

In this section, you talk about theory. You should be using current sources to explain what we currently know about the theory behind your experiment, so this section can use present-tense verbs. Exception: If you are discussing the history behind a discovery, past-tense is acceptable (i.e. “Gregor Mendel discovered the principles of inheritence by working with pea plants.”).

Materials & Methods:

Use past-tense verbs in this section. Everything you did was in the past, and this is not the place to recommend future action.

Results:

Use past-tense verbs here as well. You obtained these results in the past.

Discussion/Conclusion:

This section is where you need to be careful with your verb tenses. You will be pulling from your results, which you obtained in the past, but trying to explain them with theoretical concepts, which are current. You also use this section to recommend further action at some point in the future. The Writing Center can help you if you are confused about verb tenses.

Conciseness is everything.

Immediately throw away the idea that writing more means that you are getting a better grade. Professors can tell when you use more words than necessary just to sound smarter. Spoiler: It doesn’t work. Do not include facts in your introduction that have nothing to do with your experiment.

If you’re trying to go into science or medicine as a career, at some point you may want or need to publish a scientific paper in a journal. Reviewers will be much more ruthless than your professor will be, so start practicing conciseness now.

If you are having trouble with wordiness, again: visit the Writing Center. Science majors are not the only ones who deal with this issue.

Integrity

Oof. Here it is. Nobody wants to be accused of a lack of integrity. It has the potential to ruin not only your GPA, but your entire career. This broad category of academic no-no’s includes several different offenses, but the ones most often encountered in science are plagiarism and data fudging. Plagiarism is easy enough to avoid- don’t copy other people’s work and make sure to properly cite all of your sources, all of the time.

The temptation to change numbers here and there to make writing lab reports easier, on the other hand, will present itself from time-to-time. Feeling that temptation doesn’t make you a bad person or a bad student; however, it’s better for you in the long run to do the hard thing. Own up to your mistakes. Document them; explain them; learn from them. Most professors won’t mark you down for making a mistake in lab (unless it’s straight-up dangerous), but they will mark you down (potentially even give you a zero!) for trying to cover a mistake up by fudging data. Claiming to get results that you didn’t get is outright lying, and it is taken incredibly seriously in the scientific community. People have lost their jobs, been kicked out of college, and destroyed their professional credibility because they lied. You honestly learn more from trying to explain the results you get, however weird and screwed-up they may be, than you would learn from trying to fudge data.

If you do commit plagiarism and/or fudge data and get away with it, trust me, you’re going to feel it later. Lab reports demonstrate proof of applied knowledge that you need to take with you into your field. You could be really, really good at cheating, but once you get into industry, grad school, or med school (if you get that far without properly understanding the concepts you need), they will weed you out in 5 seconds flat. If you fudge data in an industrial or medical setting, you could be the direct cause of serious injury or death, and (as if that’s not horrible enough), you could get hit with a lawsuit so serious that your kids’ kids will be feeling the effects of it. You could go to prison. Plagiarizing someone else’s work on a patent application could result in not only a lawsuit directed at you (and possibly your employer), but also a rejected patent application, waste of company resources, and (probably) the loss of your job. If you fudge data or plagiarize in grad school (or undergrad, for that matter), you could be expelled and have it on your record forever.

We’re done here! Go forth, do good science, and write good lab reports.