Designing Experiments

Improving Your Lab Report

Improving your Title
A good title efficiently tells the reader what the report is about. It may include such information as the subject of the experiment (what it is about), the key research variables, the kind of research methodology used, and the overall findings of the experiment. To make your titles better, follow these guidelines:

  • If your title is too long (takes up more than a line), reduce it by taking out non-essential words and phrases.
  • If your title doesn't have enough information, make a list of the key words related to the experiment (scientific concept of the experiment, important variables, procedure, overall finding) and use the list to come up with ideas for further information.
  • If your title is a complete sentence (with a subject and a predicate), rewrite it so that it is not a full statement but a phrase describing the experiment.

Improving your Abstract
A good Abstract is a miniature version of the lab report in one concise paragraph and labeled Abstract.

If you are not sure what should be included in each summary sentence, use the following list as a guide:

  • Introduction: research problem of lab; hypothesis
  • Methods: a quick description of the procedure
  • Results: statement of the overall findings
  • Discussion: judgment about hypothesis; solution for the research problem
  • Conclusion: what you learned from doing the lab

If your Abstract is too long, look carefully at each summary sentence and take out any information that is not essential to that section of the report.

Improving your Introduction

  • effectively defines research problem and states research question

Defining a research problem effectively means giving a brief description of the overall problem and then analyzing it into knowns and unknowns. The knowns are what you know about the problem, typically what has been giving to you in the problem statement. The unknowns are what you don’t know, what you need to find out in order to solve the research problem. The unknowns are usually given or implied in the problem statement. A good Introduction defines the problem in such a way that the reader understands it, which means that the knowns and unknowns are stated clearly.

The second element of this part of the Introduction is the statement of the research question. It puts the unknowns in the form of a question or a statement of what needs to be found by doing the experiment.

Here is some advice on how to improve this part of the Introduction:

• If you are having trouble writing a good opening sentence for the lab report, you can say something like: “The problem for this lab was X…” “The problem we were asked to solve was X…”.
• As you are defining the problems, don’t just list the knowns and unknowns. Describe them in paragraph form.
• You can give your research question in the form of a question or as a statement, such as “To solve this problem, it is necessary to find Y…”.

  • successfully establishes the scientific concept of the lab

To establish the scientific concept for the lab you need to do two things:

1-state what the lab is about, that is, what scientific concept (theory, principle, procedure, etc.) you are supposed to be learning about by doing the lab. You should do this briefly, in a sentence or two. If you are having trouble writing the opening sentence of the report, you can try something like: "This laboratory experiment focuses on X…"; "This lab is designed to help students learn about, observe, or investigate, X…." Or begin with a definition of the scientific concept: "X is a theory that…."

2-give the necessary background for the scientific concept by telling what you know about it (the main references you can use are the lab manual, the textbook, lecture notes, and other sources recommended by the lab manual or lab instructor; in more advanced labs you may also be expected to cite the findings of previous scientific studies related to the lab). In relatively simple labs you can do this in a paragraph following the initial statement of the learning context. But in more complex labs, the background may require more paragraphs.

  • states hypothesis and provides logical reasoning for it

A good statement of the hypothesis summarizes in a sentence or two what outcomes you anticipate for the experimental procedure. Typically the outcomes will be presented in terms of the relationship between dependent and independent variables. If you are having trouble starting the paragraph on the hypothesis, try a sentence opener like this: "The hypothesis for this lab was…"; "My hypothesis was…"; "We predicted that…"; I hypothesized that…."

Providing logical reasoning for the hypothesis means explaining the reasoning that you used to make your hypothesis. Usually this reasoning is based on what you know about the scientific concept of the lab and how that knowledge led you to the hypothesis. In science, you reason from what you know to what you don't know. In a couple of sentences (more for complex labs) describe the logic that you used to reason from what you know about the scientific concept to your educated guess of the outcomes of the experimental procedure. If you need to make the logic of your hypothesis clearer, use words that indicate an explanation: because, since, due to the fact that, as a result, therefore, consequently, etc.

Often you can present the hypothesis and the supporting reasoning in one paragraph. In more complex labs, especially those with multiple procedures and therefore multiple hypotheses, you may need more paragraphs, perhaps one for each hypothesis.

Improving your Methods

A good Methods section describes what you did in the lab in a way that is easy to understand and detailed enough to be repeated. To make your Methods and better, follow these guidelines:

  • If your Methods is not easy to follow, you may ask someone to read it. Ask him or her to identify places in the procedure that are not clear and then revise those places for greater clarity. It may be more helpful to include words that help the reader follow the process of the experiment: step 1, step 2, step 3; first, then, finally; first, second, third; after, next, later, following; etc.
  • If your Methods is difficult to follow because it is long and complicated, then consider dividing it into separate parts, each with a subheading. You can divide it into the typical parts of an experimental procedure (such as Lab Set-Up, Lab Procedure, and Analysis of Data) or, if there were multiple experiments, a part for each experimental procedure.
  • If you need to add more detail to your Methods , go back to the lab manual and to the notes you or a lab partner took during the procedure and use them to help you remember what you did in the lab.

Improving your Results

  • opens with effective statement of overall findings

Results sections typically begin with a brief overview of the findings. This is where you sum up your findings. Such a statement is typically a sentence or two. This summary will act as the opening sentence for the Results. If you had trouble getting the first sentence started, here are some possibilities: "The results of the lab show that …"; "The data from the experiments demonstrate that…"; "The independent variable X increased as Y and Z were…."

  • presents visuals clearly and accurately

One of the main problems with visuals is lack of clarity. You may have chosen a form of visual that does not represent the data clearly. To see if there is a form of visual that represents the data more clearly, go to the LabWrite Graphing Resources for help.

Another problem with visuals can be ascribed to lack of accuracy. Visuals are accurate when they correctly represent the data from the experiment. If there is a problem with accuracy, you should check three points at which accuracy could be jeopardized: (1) you may have recorded the raw data from the procedure incorrectly; (2) you may have entered the raw data onto the spread sheet incorrectly; and (3) you may have made careless errors in the format of the visuals, particularly in labeling the x- and y-axes and in designating the units along those axes.

  • presents verbal findings clearly and with sufficient support

The presentation of findings in words should be ordered according the order of the visuals, each visual being described in words. Each description should include a sentence or so summarizing the visual and then any details from the visual pertinent to the data from that visual. To make the verbal part of your Results better, follow this general outline:

  • Summary of overall findings of lab
  • Paragraph related to visual 1
    • Sentence of overall finding from visual 1
    • Sentence(s) with key details from the visual 1
  • Paragraph related to visual 2
    • Sentence of overall finding from visual 2
    • Sentence(s) with key details from the visual 2
  • Paragraph related to visual 3
    • Sentence of overall finding from visual 3
    • Sentence(s) with key details from the visual 3

  • successfully integrates verbal and visual representations

The verbal representation of each visual should refer explicitly to the visual (Table 1, Figure 2, etc.). You should create the sense that the visual and the word representations of data are working together. The primary way of doing that is to cite the visuals in your verbal findings. If you had trouble integrating the verbal and the visuals, be sure you have, at a minimum, a reference to the visual in the first sentence of each paragraph when you describe the overall finding of the visual.

Improving your Discussion

  • opens with effective statement of support of hypothesis

The Discussion should start with a sentence or two in which you make a judgment as to whether your original hypothesis (from the Introduction) was supported, supported with qualifications, or not supported by the findings. To improve the opening of your Introduction, make sure your judgment is state clearly, so that the reader can understand it. There are, generally speaking, three possible conclusions you could draw:

  • the data support the hypothesis;
  • the data do not support the hypothesis; or
  • the data generally support the hypothesis but with qualifiers (tell what they are).

If you had trouble composing this sentence, try being straightforward about it, for example, "The hypothesis that X solution would increase in viscosity when solutions Y and Z were added was supported by the data."

  • backs up statement with reference to appropriate findings

After stating the judgment about the hypothesis, you should provide specific evidence from the data in the Results to back up the judgment. The first key to improving this part of the Discussion is finding specific evidence reported in the Results that you can use to back up your judgment about your hypothesis. The second key is to describe the evidence in such a way that the reader can clearly see that there is sufficient evidence that supports your judgment about the hypothesis. Be specific. Point out specific evidence from the Results and show how that evidence contributed to your judgment about the hypothesis.

  • provides sufficient and logical explanation for the statement

You should return to the scientific concept of the lab (described in the Introduction) and use that concept as a basis for explaining your judgment of the hypothesis. The student's understanding of the scientific concept may have changed by doing the lab.

Problems with the sufficiency of the explanation refer to the reader's judgment that you didn't include enough details in your explanation, that there wasn't enough of an explanation to satisfy the reader that you fully understood why the relationship between the results and hypothesis was what it was. You need to provide greater depth in your explanation. Do some brainstorming. Look again at the explanation you placed at the end of the Introduction. Jot down more details about the explanation and use those jottings to help you expand that part of the Discussion.

Problems with the logic of the explanation refer to the reader's judgment that your explanation of the support or lack of support of the hypothesis did not adhere to sound scientific reasoning. Look at the reasoning you used in the explanation. It should follow one of four basic arguments:

1. If the results fully support your hypothesis and your reasoning was basically sound, then elaborate on your reasoning by showing how the science behind the experiment provides an explanation for the results.

2. If the results fully support your hypothesis but your reasoning was not completely sound, then explain why the initial reasoning was not correct and provide the better reasoning.

3. If the results generally support the hypothesis but with qualifications, then describe those qualifications and use your reasoning as a basis for discussing why the qualifications are necessary.

4. If the results do not support your hypothesis, then explain why not; consider (1) problems with your understanding of the lab's scientific concept; (2) problems with your reasoning, and/or (3) problems with the laboratory procedure itself (if there are problems of reliability with the lab data or if you made any changes in the lab procedure, discuss these in detail, showing specifically how they could have affected the results and how the errors could have been eliminated).

You can also improve the logic of your explanation by using words that make your argument clear, such as because, since, due to the fact that, as a result, therefore, consequently, etc.

gives answer to research question and solution for unknowns

The objective of the experiment was to answer the research question, so it’s important to address that question clearly at this point in the Discussion. A good discussion of the research question will begin by restating the question or statement of what needed to be found in the experiment. It will then give an answer to the question, what the findings of the experiment suggest as the best answer to the question. Since the question is a way of capturing the unknowns, you should also show how the experiment enabled you to solve the unknowns and thus answer the question. Be sure that your discussion establishes a direct link between the solution of the unknowns and the research question.

If you are having trouble starting this paragraph, here are some suggestions: The research question for this experiment was The experiment described in this report was designed to answer the question,…”; The research reported here addressed the issue of.

  • effectively links answer of research question to solution of problem

The overall goal of the lab was to solve the research problem. The solution to the problem must be presented so that it is clear to the reader and so that it makes a direct connection between the answer to the research question (the solution to the unknowns) and the solution to the research problem.

Begin with a brief reminder of what the research problem was (it is described in the Introduction). Then describe what you propose as a solution to the problem. Finally, show how the answer to the research question led you to your proposed solution to the problem.

  • sufficiently addresses other issues pertinent to lab

A low rating in this area means that the instructor thinks that there are other interesting issues you could have discussed about your findings. Other issues that may be appropriate to address are (1) any problems that occurred or sources of error in your lab procedure that may account for any unexpected results; (2) how your findings solution to the problem compared with the solutions of other students in the lab and an explanation for any differences (check with the lab instructor first to make sure this is permissible); (3) suggestions for improving the lab.


Improving your Conclusion

  • convincingly describes what has been learned in the lab

A good Conclusion takes you back to the larger purpose of the lab: to learn something about the scientific concept, the primary reason for doing the lab. The Conclusion is your opportunity to show your lab instructor what you learned by doing lab and writing the lab report.

You can improve your Conclusion first by making a clearer statement of what you learned. Go back to the scientific concept--theory or principle or important scientific procedure--that the lab is about. If you are not sure if you have stated what you have learned directly enough, read your first paragraph to see if your reader would have any doubt about what you have learned. If there is any doubt, you may begin the paragraph by saying something like, "In this lab, I learned that ...."

Simply saying you learned something is not necessarily going to convince the reader that you actually did learn it. Demonstrate that you did indeed learn what you claimed to have learned by adding more details to provide an elaboration on the basic statement. Read over the Results and Discussion and jot down some notes for further details on what you have learned. Look carefully at the statement of what you have learned and underline any words or phrases that you could "unpack," explain in more detail. Use this brainstorming as a way of helping you to find details that make your Conclusion more convincing.

If you think you need to do more to convince your reader that you have learned what you say you have learned, provide more details in the Conclusion. For example, compare what you know now with what you knew before doing the lab. Describe specific parts of the procedure or data that contributed to your learning. Discuss how you may be able to apply what you have learned in the lab to other situations in the future.

There may be more that you have learned about from the lab experience than the scientific concept of the lab. If so, write a paragraph describing it. For example:

  • What did you learn about experimental design, how to design an experiment?
  • Was there anything in the experimental procedure that you found particularly interesting to learn how to do?
  • Did you apply a procedure for analyzing data that was useful to learn about?
  • Did you learn anything about using a spreadsheet or graphing or creating other visuals?
  • Did you learn anything about writing or about science from writing the report?

Improving your References

  • all appropriate sources in the report are listed

Every source that you formally used to write your lab report should appear in the References. These include the lab manual, textbooks, technical documents, any source you use and cite in the report.

  • citations and references adhere to proper format

Different fields tend to have different styles of documentation, that is, the way you cite a source and the way you represent the source in the References. For example, biologists use the documentation style of the Council of Biological Editors, and chemists use the style of the American Chemical Society. If you don't know what style you are expected to use in your reports (it's often given in the lab manual, check with your lab instructor. For further help you can check LabWrite Resources, "Citations and References."

Improving the Presentation of your Report

  • format of tables and figures is correct

Tables and figures should be done to professional standards, such as proper headings and captions and numbering. For help, go to LabWrite Resource: "Revising your Visuals: Tables, Graphs, and Drawings."

  • report is written in scientific style: clear and to the point

Style in this case refers to your choice of words and sentence structure. The style of science writing strives to be clear and to the point. You should avoid using grand thesaurus words and long, artfully convoluted sentences.

As to choice of words, science writing uses words that its audience (other scientists in the field) will readily understand. To outsiders, the scientific vocabulary of this language looks like a lot of jargon. But the point is that scientific words that are obscure to outsiders are usually not obscure to the insiders that comprise the scientific audience. Your writing should sound like scientific writing. This means that you should go ahead and use proper scientific terminology, but you should also choose plain, everyday words for non-scientific terminology.

Your sentences should be clear and readable for your educated audience. Avoid excessively long and meandering sentences. But don't use a lot of very short sentences, either. Vary your sentence length. If you have difficulties with making your sentences readable, read over them aloud, noting the sentences that seem to be too long or are hard to read. Rewrite those sentences so that they flow more easily.

Also, avoid using quotations. Scientists very rarely quote from source materials; they do so only when a particular wording is important to the point they are trying to make. Using direct quotations is appropriate to English papers, but not to lab reports.

  • grammar and spelling are correct

Spelling errors. First, run the spell-checker on your computer. That should take care of almost all of your spelling problems. Sometimes, however, there are words that the spell-checker does not catch because they are words that are actually spelled correctly but are used for the wrong meaning, like using "to" for "too" and "that" for "than." You should be able to spot these misuses of words by reading over the report looking for error, as described under "Making the lab report grammatically correct" immediately above.

Grammar errors. It's important that you understand that the source of grammar problems is not, for most of us, a matter of not knowing the rules of grammar. So don't worry about that. The source of most grammatical errors is simply not seeing them in your own writing. We usually read our own writing for the meaning that the words convey and not for the words themselves.

Correcting grammar problems, then, is usually a matter of learning to read our writing differently. Read your lab report at least twice specifically looking for errors in grammar. You should focus on the words and sentences themselves. You don't need any special knowledge for detecting and correcting most grammar problems. If you do read for error, you will probably be able to spot problems and correct them without having to look anything up in a handbook.

If you feel like you do need special help with grammar, go to the "On-line Writing Handbook" on the LabWrite Resources Page.

Overall Aims of the Report: The student...

  • has successfully learned what the lab is designed to teach

This is, of course, the purpose for doing the lab, to learn something about the science of the course you are taking. Reading your lab report gives your teacher a good idea of how well you have achieved this all-important aim. It's your job in the lab report to represent as fairly as you can what you have learned.

What you have learned is indicated in the report, especially the Introduction and the Conclusion. You should begin the Introduction by setting up the learning context, which is the scientific concept that forms the foundation of the lab. This is what you are supposed to be learning about in the lab. Be sure that the learning context you establish in the Introduction does indeed match the learning context from the lab manual or handout.

You can improve this part of the report also by (1) expressing more clearly what you are supposed to be learning about and (2) showing that you have a good sense of what the learning context is all about (see treatment of Introduction). In addition, check your designation of the purpose of the lab in the Introduction. Be sure that it explicitly and clearly makes the connection between the objectives of the procedure and the learning context.

The other key part of the report you should review is the Conclusion. This is where you make your strongest case for what you learned in doing the lab. You may be able to improve the Conclusion by rewriting the statement of what you have learned, rewording it so that it is clearer to the reader. You could also enhance the rest of the Conclusion by adding more details concerning what you have learned (see treatment of Conclusion above). Remember, your job is to convince your reader that you have achieved this aim, and this is the section of the report in which you do that directly.

  • demonstrates clear and thoughtful scientific inquiry

One of the objects of the lab and lab report is to give you the experience of participating in scientific inquiry, the form of thinking that defines science. In other words, you need to show through the lab report that you can think like a scientist. There are key places in the report where you indicate your ability to do that.

The first is found at the end of the Introduction where you present your hypothesis, which drives scientific inquiry. You can improve this part of the report by (1) restating the hypothesis so that it more clearly and more specifically presents your educated guess of the outcomes of the experimental procedure and (2) enhancing the logic that you use to show how you have reasoned from what you know about the scientific concept at the root of the learning context to your hypothesis. You may need to make the links in that logical chain clearer to the reader, or you may need to entirely rethink your reasoning (which could lead to a different hypothesis).

The other place in your report in which you exhibit your ability to think scientifically is in the Discussion. That's where you come back to the hypothesis to see if it is supported or not supported by the results of the procedure. First, are you making a reasonable judgment about whether or not the hypothesis is supported by the findings? Second, do you provide clear evidence from the Results that back up your judgment? And third, do you give a sound , based on your understanding of the scientific concept of the lab, for your judgment? Perhaps you need to revise your explanation so that it is more logical, provides a greater depth of discussion (more details), and treats all the facts that are relevant.

Also in the Discussion you have the opportunity to compare your results to the results of others, other students in the lab or (in more sophisticated labs) published scientific studies. This is an important aspect of scientific inquiry. Look to see that you make the necessary comparisons and that your explanations for the comparisons are full and logical.

  • accurately measures and analyzes data for lab findings

There are two ways of looking at this aim, depending on the kind of lab you are in. In some labs, there is a "right answer," a specific unknown or standard measurement you are expected to find. In these cases, the emphasis of the aim is on "expected outcomes." That is, your laboratory procedure is expected to yield certain results and, to a certain extent, the quality of your work depends on whether or not you attain those results.

In other kinds of labs, there may be no established outcome for the procedure, or it may be that doing the procedure in a scientifically sound way is more important than the particular answer you get.

In both kinds of labs, the places where you need to focus your efforts on improvement are Materials and Methods and Results. If you need to have the right answer, then you should revisit your lab notebook to search out errors in recording data and transcribing data to spread sheet and in any calculations you have done. You must rewrite your report accordingly.

But if your aim is to demonstrate that your procedures are sound and that they legitimately lead to your results, then look at these sections of the report. Is your procedure described clearly enough? Are your results presented in sufficient detail? The point is to demonstrate that there is a clear relationship between procedure and outcomes.




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