WHAT THIS HANDOUT PERTAINS TO
This handout offers general guidelines for writing reports on the scientific research you have undertaken. We will describe the conventional rules regarding format and content of a lab report as well as try to explain why these rules exist so that you will have a better understanding of how to undertake this type of writing.
BACKGROUND AND PRE-WRITING
WHAT IS THE PURPOSE OF WRITING RESEARCH REPORTS?
In your science class you participated in an experiment, and now you must write it up to submit to your teacher. You think that you had sufficient understanding of the background, designed and finished the study well, were able to gain useful data, and could to apply the data to draw conclusions about a particular scientific process or principle. However, how do you go about writing all that? What expectations does your teacher have?
To avoid guesswork in trying to ascertain this, try to think beyond the context of a classroom. Indeed, you and your teacher are both members of a scientific community, and participants in this community often share the same values. As long as you appreciate and understand these values, it is likely that your writing will satisfy the expectations of your audience, which includes your teacher.
What is your motivation for writing this research report? The most immediate answer is “because it was assigned by the teacher,” but this is thinking inside the classroom context. Broadly speaking, individuals perusing a scientific hypothesis have an obligation to the rest of the scientific community to report the findings of their research, especially if these make a contribution to or contradict previous ideas.
People going through such reports have two primary goals:
They wish to collect the information that is presented.
They seek to establish that the findings are legitimate.
As a writer, your job is to enable these two goals.
HOW DO I DO THAT?
Great question. Here is the essential format that scientists adhere to for research reports:
Methods and Materials
This format, sometimes called “IMRAD,” may be slightly modified depending on the discipline or audience. Some require you to include an abstract or separate section for the hypothesis, or refer to the Discussion section as “Conclusions,” or change the order of the sections (some professional and academic journals stipulate that the Methods section must appear last). Ultimately, however, the IMRAD format was created to be a textual reflection of the scientific method.
As you will likely recall, the scientific method requires developing a hypothesis, putting it to the test, and then determining if your results support the hypothesis.
Essentially, the format for a research report in the sciences reflects the scientific method but adds to the process a little. Below you can see a table that demonstrates how each written section corresponds to the scientific method and what information it offers to the reader.
Scientific method step
As well as…
presents your hypothesis
Articulates how you arrived at this hypothesis and how it is
related to prior research; provides the reason for the purpose
of the study
relates how you tested your hypothesis
Explains why you undertook you study in that particular
provides the uninterpreted (raw) data collected
(potentially) presents the data in table form,
as an easy-to-read diagram, or as percentages/ratios
evaluates if the data you obtained supports the hypothesis
explores the implications of your findings
and evaluates the potential limitations
of your experimental design
Conceptualizing your research report as derived from the scientific method albeit fleshed out in the ways noted above. Our advice enables you to meet the expectations of your audience. We will continue by explicitly drawing connections between each component of a lab report to the scientific method, and then provide the rationale regarding how and why you must elaborate the respective section.
Although this handout addresses each component in the order, it should be presented in the final report, for practical reasons you may decide to write your sections in a different order. For instance, often writers find that writing the Methods and Results section before the others helps them to clarify their conception of the experiment or study as a whole. You might think about utilizing each assignment to try out different methods for drafting the report in order to determine which works best for you.
WHAT SHOULD I DO BEFORE DRAFTING THE LAB REPORT?
The optimal way to prepare to compose the lab report is to ensure that you have full comprehension of everything you need to know about the experiment. Clearly, if you do not really understand what happened in the lab, you will find it hard to explain it to another person. To ensure that you have sufficient knowledge to compose the report, complete the following steps:
What knowledge are we hoping to gain from this experiment?
Read your lab manual extensively, and far ahead of when you begin the experiment. Consider the following questions:
What is the procedure going to be for this lab?
Why are we following this procedure?
What knowledge are we hoping to gain from this experiment?
How might this knowledge contribute positively to our work?
Providing answers to these questions will promote a more complete understanding of the experiment, and this knowledge of the larger picture will enable you to write a successful lab report.
Consult with your lab supervisor as you undertake the experiment. If you don’t know how to respond to one of the above questions, your lab supervisor will probably provide you with an explanation or guide you towards the proper response.
In collaboration with your lab partners, plan the steps of the experiment carefully. The less you are hurried, the more likely you are to do the experiment correctly and accurately document your findings. Also, invest some time to consider the best way to organize the data before you have to start recording it. If you can, create a table to account for the data; this will often work better than merely jotting down the results in a rushed fashion on a scrap of paper.
Record the data carefully to ensure that it is correct. You will be unable to trust your conclusions if you have erroneous data, and your readers will see you made an error if the other people in your group have “97 degrees, ” and you have “87.”
Do everything in consultation with your lab partners. Frequently lab groups make one of two mistakes: two people undertake all the work while two spend the time socializing, or everybody works together until the group finishes gathering the raw data, then makes a hasty exit. Collaborate with your group members, even when the experiment is finished. What trends did you observe? Was there evidence to support the hypothesis? Did all of you arrive at the same results? What kind of figure or image should you employ to represent your findings? The whole group can work collaboratively to provide answers to these questions.
Take your audience into consideration. You may think that audience is not important: it is just your lab TA. True, but again think beyond the classroom context. If you write only with the instructor in mind, material that is crucial to a full understanding of your experiment may be omitted as you assume the instructor was already familiar with it. Consequently, you might receive a lower grade as your TA will not be sure that you have adequately grasped all of the principles at work. Try to aim your writing towards a fellow student in a different lab section – he or she will have some degree of scientific knowledge but won’t have a full understanding of your experiment specifically. Or, write towards yourself five years later after the reading and lectures from this course are not so fresh in your mind. What aspects would you retain, and what would you require to be more fully explained as a refresher?
After you have finished these steps as you go through the experiment, you will be in a good position to draft a strong lab report.
HOW DO I WRITE A STRONG INTRODUCTION?
For present purposes, we will consider the Introduction to comprise four basic elements: the intent, the relevant scientific literature, the hypothesis, and the reasons why you held that your hypothesis was viable. We will begin by addressing each element of the Introduction to explain what it covers and why it is significant. Then we will be able to develop a logical organization method for the section.
Including the purpose (otherwise known as the objective) of the experiment frequently confuses the writers. The largest misunderstanding is that the purpose is identical to the hypothesis. This is not completely accurate. We will address hypotheses shortly, but essentially, they contain some indication of what you expect your experiment to demonstrate. The purpose goes beyond that and engages more with what you expect to achieve through the experiment. In a professional context, the hypothesis may pertain to how cells react to certain types of genetic manipulation, yet the purpose of the experiment is to gain knowledge about potential cancer treatments. Reports at the undergraduate level rarely have such a wide-ranging goal, yet you should still attempt to maintain a distinction between your hypothesis and your purpose. For example, in a solubility experiment, your hypothesis might address the relationship between temperature and the rate of solubility, yet the purpose is likely to gain knowledge regarding some specific scientific principle underlying the process of solubility.
To begin with, many individuals maintain that you should write down your working hypothesis before you begin the experiment or study. Frequently, beginning science students fail to do so and thus struggle to recall exactly which variables were involved or how the researches deemed them to be related. You will thank yourself later if you write down your hypothesis as you develop it.
Regarding the form a hypothesis should have, it is a good idea to try to avoid being fancy or overly complicated – here the clarity is what is important, not an inventive style. It is perfectly acceptable to begin your hypothesis with the phrase “It was hypothesized that . . .” Be as specific as possible regarding the relationship between different objects of your study. That is, explain that when term A alters, term B alters in this particular way. Audiences of scientific writing are seldom content with the notion that a relationship between two terms exists – rather, they wish to know what is entailed by that relationship.
Not a hypothesis: “It was hypothesized that there is a significant relationship between the temperature of a solvent and its solubility rate.”
Hypothesis: “It was hypothesized that when the temperature of a solvent increases, its solubility rate will likewise increase.”
A suitable hypotheses should have both an independent as well as a dependent variable. The independent variable is what you alter to test the reaction; the dependent variable is what changes as a result of your alterations. In the example above, the independent variable is the temperature; the dependent variable is the solubility rate. Both should be used in your hypothesis.
JUSTIFY YOUR HYPOTHESIS
You are required to contribute more than simply relating to your readers what your hypothesis is; you are also required to persuade them that this was a reasonable hypothesis, given the circumstances. That is, utilize the Introduction to make clear that you didn’t just randomly select a hypothesis (and if you did, problems with your report likely go far beyond using the appropriate format!). If you suggest that a particular relationship exists between the independent and the dependent variable, what made you believe your estimation might be supported by evidence?
This is often referred to by scientists as “motivating” the hypothesis, explaining why something encouraged them to make that prediction. Frequently, motivation includes what is generally accepted as true by scientists (see “Background/previous research” below). However, you can also motivate your hypothesis by incorporating logic or your own observations. If you are attempting to discern which solutes will dissolve more quickly, you might recall that some solids are meant to dissolve in hot water (e.g., sugar) and others – because they are unaffected by high temperatures (i.e., what saucepans are made out of). Alternatively, you can consider if you have noticed sugar dissolving more quickly in a glass of iced tea or a cup of coffee. Even such common, outside of the lab observations can help you establish your hypothesis as a reasonable one.
This component of the Introduction makes clear to your reader how you are building on the work of other scientists. If you imagine the scientific community are participating in a series of conversations addressing various topics, you will see that the relevant background information will indicate to your reader which conversation you want to engage with.
Broadly speaking, the reasons students employ the background differs to some degree from authors writing journal articles. Given that the audiences of academic journals are often professionals in the field, authors articulate the background so as to allow readers to determine the study’s relevance to their own work. Students, on the other hand, are writing with a much more narrow audience of peers in the course or their lab instructors. Consequently, it is necessary for students to make clear their understanding of the context for the experiment or study they have completed. For instance, if your instructor has been discussing polarity during class, and you are undertaking a solubility experiment, you might attempt to connect the polarity of a solid to its relative solubility in certain solvents. In any case, both undergraduates as well as professional researchers must make a clear connection between the background material and their own work.
ORGANIZATION OF THIS SECTION
Most of the time writers begin by articulating the purpose or objectives of their own work, which makes clear for the benefit of the reader the “nature and scope of the problem investigated” (Day 1994). After you have articulated your purpose, it should be easier to move from the general purpose to relevant material pertaining to the subject (to your hypothesis). In a condensed form an Introduction section might resemble this: “The goal of the experiment was to test previously held ideas pertaining to solubility in the experiment [purpose] . . . According to Whitecoat and Labrat (1999), the molecules increase speed when subjected to higher temperatures… Class material has informed us that molecules which move at faster rates bump into each other more frequently and consequently break down with greater ease … Thus it was hypothesized that when a solvent increases in temperature, the solubility rate also increases [hypothesis]”
Note, these are guidelines rather than firm exhortations. The example above simply provides an sample of a common way to organize the material.
METHODS AND MATERIALS
WRITING A STRONG MATERIALS AND METHODS SECTION
Your Methods section should fulfill the readers’ expectations; thus you must understand its purpose. We will review the purpose as we articulated it above: in this component, you will wish to describe in detail how you tested your hypothesis as well as make clear the rationale for your procedure. In the sciences, it is not enough to simply design and undertake an experiment. Others must be able to verify your findings, so the experiment must be reproducible so far as other researchers could follow the same methodology and arrive at the same (or similar) results.
Here is a concrete example which demonstrates how important reproducibility is. In 1989 physicists Stanley Pons and Martin Fleischman stated that they had discovered “cold fusion” which is a way of creating excess heat and power without the need for nuclear radiation that goes along with “hot fusion.” These reports generated a great deal of interest, as such a discovery could have significant implications for the industrial production of energy. Yet when other scientists attempted to duplicate the experiment, they arrived at different results, and consequently many dismissed the conclusion as unjustified (or ever worse, as a hoax). Even in the present day, the viability of cold fusion is still a subject of debate within the scientific community, although an increasing number of researchers admit that it is a possibility. Thus, when you compose your Methods section, bare in mind that you must describe your experiment thoroughly enough that others would be able to reduplicate it exactly.
Keeping these aims in mind, we will consider how to compose a strong Methods section regarding content, structure, and style.
Occasionally, the most difficult aspect of writing this component is not what you should discuss, but what you should not discuss. Writers frequently wish to include the results of their experiment as they have measured and recorded these throughout the experiment. Yet this data should be reserved for the Results section. In the Methods section you can note that you recorded the results, or how you documented the results (for example, in a table), but you should refrain from writing what the results were. In this part, you are simply articulating how you proceeded to test your hypothesis. As you work through a draft of this section, ask yourself the following questions:
How much detail should be included? Be exact in giving details, but make sure they are relevant. Ask yourself: “If this piece were a different size or made from a different material, would this have an impact?” If the answer is no, you likely don’t need to go too much into the detail. If that is a yes, report as many facts as necessary to ensure that other scientists can duplicate it. The most important detail is measurement, and you should always specify, for example, time elapsed, temperature, mass, volume, etc.
Rationale: Make sure that as you are conveying your actions during the experiment, you articulate your reasons for the protocol you developed. For example, if you capped a test tube immediately after adding a solute to a solvent, why did you do that? In a professional context, writers provide their reasons as a means to explain their thought process to potential detractors. On the one hand, naturally, that is your impetus for discussing protocol, as well. On the other hand, since pragmatically speaking you are also writing for your teacher (who is seeking to evaluate how well you understand the principles of the experiment), articulating the rationale demonstrates that you comprehend the reasons for conducting the experiment in that way and that you are not just following instructions. Critical thinking is vital, which is why robots do not make very good scientists.
Control: The majority of experiments will include some control, which is a way of comparing results of the experiment. (Sometimes you will require more than one control, depending on the number of hypotheses you wish to test.) The control is identical to the other items you are testing, except that you do not manipulate the independent variable, which is the condition you are altering to check the effect on the dependent variable. For instance, if you are testing solubility rates at increased temperatures, your control would be a solution that you did not heat at all; this way, you will see how quickly the solute dissolves “naturally.”
Describe the control in the Methods section. Two things are particularly crucial in writing about the control: identify the control as a control, and explain what you are controlling for.
STRUCTURE AND STYLE
The organization is particularly vital in the Methods section of a lab report as readers must fully comprehend your experimental procedure. Frequently writers are surprised by the challenges to convey what they did during the experiment, as after all, they are only reporting an event. There is a relatively standard structure you can employ as a guide, and following the stylistic conventions can aid in clarifying your points.
Subsections: Sometimes researchers employ subsections to report their procedure when the following circumstances apply: 1) if they have used a significant amount of materials; 2) if the procedure is unusually complicated; 3) if they have developed a procedure that their readers will unlikely be familiar with. Since these conditions rarely apply to the experiments you will perform in a classroom setting; most undergraduate lab reports will not require the use of subsections. Indeed, many guides on writing lab reports recommend that you attempt to limit the Methods component to a single paragraph.
Narrative structure: Envision this section as relating a story about a group of individuals and the experiment they performed. Articulate what you did in the order in which you did it. We are used to reading about events in a chronological way, and so your readers will likely comprehend what you did if you relate that information in the same way. Moreover, because the Methods component does generally appear as a narrative (story), you will wish to avoid the “recipe” approach: “First, do that; then, do that.” Your is informing the reader on what did happen, not instructing them how to perform the experiment. Hint: the majority of the time, the recipe approach is the product of copying down the steps of the procedure from the instructions given in class.
The use of Past tense: you are describing something that already happened, so the past tense is appropriate to refer to what you did during the experiment. Writers are often inclined to use the imperative voice (“Add 5 g of the solid to the solution”) given that that is how their lab manuals are phrased; less frequently, they use present tense (“5 g of the non-liquid are added to the solution”). The past tense is more appropriate in this section because the experiment already happened.
Passive vs. active: Previously, scientific journals discouraged their writers from using the first person (“I” or “we”), as it was thought that the researchers themselves were not personally significant to the procedure in the experiment. Recall that other researchers should be able to reproduce experiments exactly, based on the lab report; utilizing the first person implies (to some readers) that the experiment cannot be replicated without the original researchers present. To help curtail the use of personal references in lab reports, scientific conventions also stated that researchers should use passive voice. The majority of readers think that this style of writing conveys information more clearly and concisely. This rhetorical decision consequently brings two scientific values into conflict: objectivity versus clarity. Given that the scientific community has not yet arrived at a consensus about which style it prefers, you may want to consult with your lab instructor.
HOW DO I WRITE A STRONG RESULTS SECTION?
Here’s something of a paradox. The Results section is often both the briefest (yay!) as well as the most significant (uh-oh!) component of your report. Your Materials and Methods section demonstrates how you arrived at the results, and your Discussion component explores the relevance of the results, so clearly the Results section forms the backbone of the lab report. This component gives your readers the most vital information about your experiment: the data that allow you to articulate how your hypothesis was or wasn’t supported. However, it does not provide anything else, which accounts for why this section is most often shorter than the others.
Before you compose this section, examine all the data you collected to determine what relates significantly to your hypothesis. This is the material you will wish to highlight in the Results. Refrain from the desire to include every bit of data you collected, as not all have relevance. Also, this is not the place to draw conclusions regarding the results—save them for the Discussion section. In this section, you’re relating facts, so nothing your readers could argue with should appear in the Results component.
The majority of Results sections contain three distinct parts: text, tables, and figures. We will consider each part individually.
This should be a concise paragraph, generally speaking merely a few lines, which describes the results you derived from your experiment. In a relatively simple experiment, the text can comprise the whole Results component. Don’t think that you must compensate for a short (but effective) text with excessive amounts of detail; your readers appreciate conciseness more than your capacity to recite facts. In a more complex experiment, tables or figures could be included to help illustrate to your readers the most significant information you gathered. In this instance, you are required to address each table or figure directly, as appropriate: “Table 1: the rates of solubility for each substance”.
It is possible to note the trends that emerge when you go through the data. Although because identifying trends relies on your own judgement and thus may not feel like impartial reporting, it cannot be denied that these trends are important, and thus they do belong in the Results section. For example: “Heating the solution increased the rate of solubility of polar solids by 45% but had no impact on the rate of solubility in solutions containing solids that are non-polar.”
As is the case with the Materials and Methods section, you should refer to the data using the past tense as the events you recorded have already been completed. In the above example, the use of “increased” and “had,” rather than “increases” and “has.”
Avoid putting information on the table that also is contained in the text. Also, a table should not be used to present data that is irrelevant, just so you can demonstrate that you did collect these data throughout the experiment. Table are great for some purposes and in some instances, but not all, so if and how you will utilize tables is dependent on what you require them to accomplish.
Tables are a helpful means to show variation in data, but not to present a significant amount of unchanging measurements. For example, if you are engaged with a scientific phenomenon that only happens within a certain range of temperature, you do not need to employ a table to demonstrate that the phenomenon didn’t happen at any of the other temperatures. How useful is this table?
As you can likely discern, no solubility was noted until the trial temperature reached 50°C, the fact that the text part of the Results section could indicate. The table can show what occurred at 50°C and higher, which will better illustrate the differences in solubility rates when solubility did happen.
Try to abstain from using a table to articulate any aspect of the experiment that you can address in one sentence of text. Here is an example of an unnecessary table from How to Write and Publish a Scientific Paper, by Robert A. Day:
As Day observes, all the information in this table can be summarized in one sentence: “S. griseus, S. coelicolor, S. everycolor, and S. rainbowenski gain in size under aerobic conditions, whereas S. nocolor and S. greenicus depended on anaerobic conditions.” A table will not be any clearer to readers than that one sentence.
When you do have occasion to tabulate material, try to ensure the clarity and readability of the format you use. Here are some tips:
Number your table. So, when you refer to the table in the text, employ that number to indicate to your readers which table they can look at to clarify the material.
Give your table a title. The title should be sufficiently descriptive to communicate its contents, but no so long that it becomes unwieldy. The titles in the sample tables above are an appropriate length.
Organize your table so that readers read vertically, not horizontally. Generally speaking, this means that you should design your table so that similar elements read down, rather than across. Consider what you wish your readers to compare, and place this information in the column (up and down), rather than in the row (across). Often what is being compared is numerical data collected from the experiment, so take particular care to ensure that you have columns of numbers, not rows. Here is an example of how significantly this decision has an impact on the readability of your table. Consider the table, which presents the data in rows arranged horizontally.
It is a bit difficult to comprehend the trends that the author presumably wants to demonstrate in this table. Compare this table, where the data is arranged vertically:
The second table demonstrates how placing similar elements in a vertical column makes for easier reading. In this instance, the similar elements are the measurements of length and height, over five trials–not, as shown in the first table, the length and height measurements for each trial.
Ensure you include units of measurement in the tables. Readers might be able to discern that you measured something in millimeters, but don’t force them to do this.
Line up numbers on the right, such as this:
or on the decimal point. It may be helpful to imagine that you are going to add the numbers together and place them sequentially.
Do not employ vertical lines as a component of the format for your table. This convention is adhered to because journals prefer not to have to reproduce these lines as consequently the tables are more expensive to print. Although it is reasonably unlikely that you’ll be submitting your Biology 11 lab report to Science for publication, your readers nonetheless still retain this expectation. Thus, if you employ the table-drawing option in your word-processing software, select the option that doesn’t rely on a “grid” format (where there are vertical lines).
What is the best way to include Figures in my Lab report?
Even thought-through tables can be useful ways of demonstrating trends in your results, figures (i.e., illustrations) can be even more helpful to emphasize these trends. Lab report writers frequently employ graphic representations of the data they gathered to give their readers a literal picture of how the experiment proceeded.
WHEN SHOULD YOU EMPLOY A FIGURE?
Recall the circumstances when you do not need to use a table: when you do not have a significant amount of data, or when the data you have do not show many variations. Under the same circumstances, you would likely forgo the figure as well, as the figure would not likely contribute an additional perspective. Scientists prefer not to waste their time, so they rarely respond well to redundancy.
If you are attempting to decide between using a table and creating a figure to represent your material, keep in mind the following a rule of thumb. The merits of a table are in its ability to provide large amounts of exact data, whereas the strength of a figure is its illustration of important facts that occurred during the experiment. If you feel that your readers won’t grasp the full impact of your results solely by looking at the numbers, then a figure could well be a good addition.
Naturally, a class at the undergrad level may require you to create a figure for your lab experiment, if only for the reason to demonstrate that you are capable of doing so effectively. In this instance, do not stress about whether to employ figures or not—instead, focus on how best to accomplish your task.
Figures can include maps, photographs, pen-and-ink drawings, bar graphs, flow charts, and section graphs (“pie charts”). However, the most common figure, particularly for undergraduates, is the line graph, so this is what we will focus on here.
At the undergraduate level, it is often feasible to draw and label your graphs by hand, so long as the result is clear, legible, and drawn to scale. However, computer technology has made creating line graphs significantly easier. The majority of word-processing software has several functions for transferring data into graph form; many scientists have found Microsoft Excel, for instance, a helpful tool to graph their results. If you plan to pursue a career in the sciences, it would be a good idea to learn to use a similar program.
Computers cannot, however, determine how your graph really works; you have to understand how to design your graph so that it will meet the expectations of your readers. The following are some of these expectations:
Keep it as simplistic as you are able. You may be inclined to indicate the complexity of the information you gathered by attempting to design a graph that accounts for that complexity. However, remember why you are using a graph: to highlight your results in a fashion that is easy to see and understand. Do not force the reader to stare at the graph for an extended period of time to find the important line among the mass of other lines. Have three to five lines in a graph to achieve the best effect; if you have more data to demonstrate, utilize a set of graphs to present it, rather than attempting to force it all into a single figure.
Plot the independent variable on the horizontal (x) axis and the dependent variable on the vertical (y) axis. Keep in mind that the independent variable is component that you altered during the experiment and the dependent variable is the condition that you measured to see if it changed along with the independent variable. Placing the variables along their appropriate axes is really done because of convention, but given that your readers are used to viewing graphs in this way, it is better to not challenge the convention in your report.
Label each axis carefully, and be particularly diligent in including units of measure. You must ensure that your readers completely understand what your graph indicates.
Number and title your graphs. Similar to tables, the title of the graph should be informative yet concise, and you should refer to your graph by number in the text.
The majority of editors of academic journals in the science field prefer that writers distinguish the lines in their graphs by attaching a symbol to them which is often a geometric shape (triangle, square, etc.), and employing that symbol throughout the curve of the line. For the most part, readers have difficulty distinguishing between dotted lines and dot-dash lines from straight lines, so you may wish to avoid this system. Because colors are costly to produce, generally editors do not wish to see different-colored lines within a graph; however, colors may be a great choice to utilize for your purposes, so long as you do not intend to submit your paper to Nature. Use your discretion and try to use whichever technique most effectively dramatizes the results.
Try to gather data at regular intervals, so the plot points on your chart are not too distanced from one another. You cannot be sure of the line you should create between the plot points if these show up at the far corners of the graph; over the course of fifteen-minutes, the change may have occurred in the first or last thirty seconds of that period (and if so your straight-line connection between the points is misleading).
If you are concerned that you did not collect data at sufficiently regular times throughout your experiment, go ahead and connect the points with a straight line, but it may be advisable to address this in the Discussion section.
Make your graph big enough so that everything is legible and clearly demarcated, but not so big that it either overwhelms the rest of the Results section or provides a much greater scope than you require to illustrate your point. For example, if the seedlings of your plant grew only 15 mm during the experiment, you don’t need to create a graph that accounts for 100 mm of growth. The lines in your graph should essentially fill the space created by the axes; if you see that your data is confined to the lower left portion of the graph, you should likely re-adjust your scale.
If you design a series of graphs, ensure that they are of the same dimensions and formatting, and this includes things such as captions, symbols, scale, and so forth. It is best to be highly consistent with your visuals to allow your readers to readily grasp the comparisons you are trying to get them to see.
HOW DO I WRITE A STRONG DISCUSSION SECTION?
The discussion section is probably the most informal component of the report, as it is difficult to apply the same structure to every type of experiment. To state this simply, in this section you inform your readers how they should view the Results you arrived at. If you have completed the Results component well, your readers should already recognize the trends in the data and have a relatively clear understanding of whether your hypothesis was supported. Since the Results component can seem so self-explanatory, often students face difficulty in determining which material should be added in this final section.
Essentially, the Discussion is comprised of several parts, in no particular order, but generally moving from specific (i.e., related solely to your experiment) to more general (how your findings engage in the larger scientific community). As a rule, in this section you will be required to:
Articulate if the data support your hypothesis
Concede any anomalous data or deviations from what you were anticipating
State conclusions, predicated on your findings, about the process you’re studying
Draw connections between your findings and earlier work in the same area (if this is possible)
Explore what the theoretical and/or practical implications of your findings might be
Consider some dos and don’ts for each of these objectives.
EXPLAIN WHETHER THE DATA SUPPORT YOUR HYPOTHESIS
This statement is most often a great way to begin the Discussion, as you will not be able to speak about the larger scientific value of your study in an informed manner until you have grasped the specifics of this experiment. You can start this component of the Discussion by explicitly identifying the relationships or correlations your data indicate between the variables you altered and those that you kept controlled. Following this you can elaborate in a more transparent fashion why you believe your theory was or was not supported. For example, if you subjected solubility to differing temperatures, you might commence this component by noting that solubility rates increased in relation to those of temperature. If you began with the theory that altering the temperature would not have an affect on solubility, you would then say something a long the lines of “The hypothesis that temperature change would have an impact on solubility was not supported by the data.”
Note: Students often perceive labs as pragmatic tests of irrefutable scientific truths. Consequently, you may be inclined to claim that the hypothesis was “proved” or “disproved” or that it was “correct” or “incorrect.” However, these terms indicate a level of certainty that you as a scientist are not supposed to possess. Recall that you are testing a theory through a procedure that only lasts a small amount of time and utilizes only a small amount of trials, which significantly limits your capacity to be certain about the “truth” you observe. These terms, however, reflect a degree of certainty that you as a scientist should not claim possession of. Such word choices such as “suggest” or “imply” are more accurate ways to discuss your hypothesis.
Also, note that articulating whether the data supported your hypothesis or not includes issuing a claim that you must defend. Consequently, you must be able to demonstrate to your readers that this claim is supported by the evidence. Ensure that you are very explicit concerning the relationship between the evidence and your conclusions drawn from it. This is challenging for many writers because we infrequently justify conclusions in our normal lives. For example, you must whisper to a friend at a party that another guest is drunk, and when your friends observes the person you referred to she might quickly agree. By contrast, in a scientific paper you are required to defend your statement more concretely by noting data such as slurred speech, awkward gait, and a lampshade being worn as a hat. Additionally, you must also demonstrate how (according to previous studies) these outward behaviors are consistent with being intoxicated, particularly if they appear in conjunction with one another. To phrase this a different way, you must convey to your readers exactly how you moved from point A (was your hypothesis supported?) to point B (yes or no).
ACKNOWLEDGE ANY ANOMALOUS DATA, OR DEVIATIONS FROM WHAT YOU EXPECTED
You need to consider these exceptions and divergences so that you are able to sufficiently qualify your conclusions. For obvious reasons, your readers will question your reliability if you (deliberately or accidentally) overlook a significant piece of data that doesn’t cohere with your perspective on what transpired. In a more philosophical sense, once you have ignored evidence that contradicts your claims, you are no longer engaging in the scientific method. The inclination to “tidy up” an experiment is frequently compelling, but if you succumb to it, you are no longer doing good science.
Occasionally after you have performed a study or experiment, you become cognizant that some components of the methods you employed to test your hypothesis were flawed. In that case, it is acceptable to observe that if you had the opportunity to conduct your test again, you would potentially alter the design in this or that particular way to avoid such and such a problem. What is paramount in making this approach work, however, is to be extremely precise in identifying the weakness in your experiments, and to articulate why and how you believe that it might have had an impact on your data, as well as how you might change your procedure to eliminate or limit the effects of that weakness. Frequently researchers with limited experience feel a desire to explain “wrong” data (but recall that there is no such thing), and consequently, they broadly speculate regarding what might have thrown the experiment off. These speculations include factor such as the temperature of the room, or that their lab partners potentially read the meters incorrectly, or equipment which could have been defective. These attempts at explanations are called “cop-outs,” or “lame” by scientists; don’t indicate that the experiment had a weakness unless you are relatively certain that a) it really occurred and b) you can articulate fairly well how that weakness impacted your results.
DERIVE CONCLUSIONS, BASED ON YOUR FINDINGS, ABOUT THE PROCESS YOU ARE STUDYING
For example, if your hypothesis addressed changes in solubility at different temperatures, then attempt to determine what you can rationally say about the process of solubility. If you are an undergrad, the paper will probably be in some way related to the content you have been covering in class, so returning to theses resources may assist you in thinking more clearly about the process as a whole.
This component of the Discussion section is another location where you need to ensure that you are not overreaching. Again, nothing you have discovered in one study would permit you to claim that you now “know” something, or that something is not “accurate” or that the procedure “proved” a given scientific principle or rule. Be cautious before you embark on such stipulations, as they are often falsifiable. Instead, employ language that is more tentative, including vocabulary such as “imply” “point to” “correlation” “likely” “undermine,” and so forth.
Draw Correlations between your results and prior work in the field (if feasible)
So far we have talked about how to demonstrate that you belong in a given community (such as biologists or anthropologists) by utilizing the writing conventions they are familiar with and accept. Another means of doing so is to attempt to locate a conversation occurring between members of that community, and utilizing your work to advance that conversation. In a broader philosophical sense, scientists are unable to fully comprehend the full implications of their research unless they have a grasp of the context it which it was provoked and nourished.
That is, you must be able to identify what’s new about your project (potentially, anyway) and how it contributes to the wider body of scientific knowledge. Particularly for undergraduates, on a more pragmatic level, connecting previous research to your own will make clear to your TA that you are cognizant of the larger picture. The Discussion section affords you the opportunity to set yourself apart from other students in the class who are not thinking beyond the rudimental aspects of the study. Make the most of this opportunity by placing your own work in a broader context.
If you are a new comer to working in the natural sciences (for example, a first-year biology or chemistry student), it is highly likely that the work you will be completing has previously been performed and re-performed to an acceptable degree. Consequently, you could likely note a similar experiment or study and compare/contrast your results and conclusions with it. More advanced work may address an issue that is rather less “resolved,” and so previous research may consist of an ongoing debate, and you can employ your own research to contribute to that debate. For example, if researchers are engaged in a debate regarding the merits of herbal remedies to treat a cold, and the results from your study indicate that Echinacea reduces the symptoms of the cold though not its actual presence, then in the Discussion section you may wish to devote some time to summarize the specifics of the debate as it pertains to Echinacea as an herbal remedy. (Consider that you have likely already written about this dispute as background research in your Introduction).
EXPLORE THE THEORETICAL AND/OR PRACTICAL Potential Consequences OF YOUR RESULTS
Addressing this is frequently the optimal way to conclude your Discussion (and, essentially, the report). Generally speaking, in argumentative writing, you should aim to utilize your concluding remarks to make clear the main point of your writing. This main point can be mostly theoretical (“now that you have the comprehension of this information, you are better suited to understand the broader issue”), or mostly practical (“You can utilize this information to pursue such and such an action”). Either way, the concluding remarks aid your reader to understand the significance of your project and the why you chose to write about it.
Because a lab report is argumentative – in that you are examining a claim and determining the legitimacy of this claim by producing and gather evidence – it is frequently a wise decision to conclude your report with the same technique you utilized for establishing your main point. If you opt to pursue the theoretical route, you could discuss the implications your work has for the field or phenomenon you are examining. To again provide examples pertaining to solubility, you could conclude by considering what your work on solubility as a function of temperature tells us in general context. (Some think this type of discussion“pure” as opposed to “applied” science, although such labels can be problematic.) If you prefer to go the pragmatic route, you could conclude by considering the potential medical, institutional, or commercial implications of what you discovered—that is, respond to the question, “What can this study help people to do?” In either instance you will be making the experience of your readers more satisfying in providing them with reasons regarding why they invested their time in learning what you taught them.