How To Write A Lab Report

how to write a lab report

Scientific Reports

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:

 

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:

  • Introduction

  • Methods and Materials

  • Results

  • Discussion

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.

Section

Scientific method step

As well as…

Introduction

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

Methods

relates how you tested your hypothesis

Explains why you undertook you study in that particular

way.

Results

provides the uninterpreted (raw) data collected

(potentially) presents the data in table form,

as an easy-to-read diagram, or as percentages/ratios

Discussion

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 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.

INTRODUCTION

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.

INTENT

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.

HYPOTHESIS

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.

BACKGROUND/PREVIOUS RESEARCH

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.

CONTENT

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.

RESULTS

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.

TEXT

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.”

TABLES

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).

FIGURES

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.

DISCUSSION

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.


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