5-6 Forestry paper with graphs, due 4.15

How to Write a Lab Report

Forest Biology (FRST 200 and 210)

Read this document carefully, it outlines the content and formatting that should be used for

lab reports in FRST 200 or 210 and will be the basis for our marking system. You should note that

marking for your first lab report will be reasonably relaxed, but in the second and subsequent reports

the number of marks deducted for mistakes will increase substantially. This system encourages you

to rapidly adopt a simple, clear and systematic style of scientific writing. The easier your report is to

read the more likely you are to get good marks.

1. Report Purpose

You should aim to produce a clear, concise report that reviews current knowledge on the

subject, develops the research objectives, summarizes the methods used, and presents the results

generated. You should then discuss how the results meet the objectives and what they mean relative

to the current knowledge or literature that was used to develop your objectives, which may include

applications to which this knowledge is relevant.

2. Report Structure & Content

Use the following sections to structure your report. Pay close attention to the section details

and suggested content. All sections should be concise and informative.

Introduction

The introduction provides readers with the background information required to understand

the whole report. Introductions are funnel-like, starting broadly with an introductory sentence that

introduces the report’s context, and ending narrowly with a clear definition of specific objectives or

questions being investigated in your report (example 1). We generally leave objectives open-ended,

so you can tailor the objectives to your interests e.g., wood production, conservation, biology.

Relevant background information fills the funnel, setting up any objectives of the study, and any

hypotheses you wish to test that will be covered in your discussion section.

Example 1: Your report is comparing the wood quality of two timber species, Picea abies and Pinus

sylvestris. A good introductory sentence could be, “Wood quality, a trait in which many species vary

substantially, is an important determinant of timber value.” Your introduction then should provide

some background information that would be relevant to the reader, and narrows the focus from

wood quality in general down to more specific aspects. Potential topics might include: economic

value of high-quality wood; features that contribute to wood quality (especially whichever ones you

measured); or variability in these features. This can be further narrowed to the species being

studied: compare and contrast life histories, growth rates, relative importance to the timber industry,

etc. Now that the reader has some knowledge of wood quality and your species, you can establish

your objectives i.e., the question your study is trying to answer: “While Picea abies and Pinus

sylvestris are both important to European timber production, the quality of their mature wood has not

been adequately assessed." Your last sentence should briefly summarize what you’ve done to

address your objective: “In this study, differences in tracheid length and extractives content were

compared between Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.).”

Assume that your reader is educated, but unfamiliar with your subject. Therefore, the

introduction should also define and contextualize any terminology that is fundamental to your study.

To do this you will need to concisely summarize relevant information from class notes and include

background research. In most cases, this will include citing relevant scientific literature. Do not

include any methods, results or conclusions in your introduction.

Your introduction section should conclude with your hypotheses. These are the scientific

statements that you wish to test in your lab report. You should provide an explanation of why you

developed your hypotheses, followed by a list of your hypotheses. These hypotheses are the basis of

your discussion. Your hypotheses must be testable, and provide a predicted direction of the

relationship (example 2). This will allow you to later assess whether your hypotheses were supported

or refuted by your data.

Example 2: For the previously mentioned research topic, a good hypothesis section might be as

follows: “As Scots pine generally has a higher growth rate than Norway spruce, it was expected that

Scots pine wood will exhibit more traits consistent with fast-growing species. As such, the authors

predicted that Scots pine wood would have longer tracheids than Norway spruce, more earlywood,

and lower wood density”.

Materials and Methods

The materials and methods is an account of how your experiment was conducted, and why it

was conducted this way. This should concisely provide enough information so that your experiment

could be repeated exactly. Materials and methods must be written in clear sentences, not in point

form. Materials should be incorporated into the methods, not included separately (example 3). Be

sure to outline all the different types of data collected, the measurements that were made, and the

units of measurement used. Also include information regarding your data analysis. How was your raw

data used to answer your hypotheses? Describe any drawings that were made and their purpose (do

not include the actual drawings here). If you used any scientific equipment, try to provide as much

information about it as possible (e.g., equipment name and model number; example 3). If you used

software to analyze your data, include what you used and which version. Any relevant equations that

were used to transform your data must be included within your methods.

Do not include unnecessary details about how the lab was performed. Remember that this is

meant to be an account of how your experiment was conducted, not your forestry lab. For example,

another scientist does not need to know that you collected data in groups of three or that the TA

compiled your class data. Do not copy the lab instruction sheet which describes what you should do

during the lab, not what you did during the experiment. You should summarise the methods in your

own words.

Example 3: Good methods might read “1 cm2 cubes of mature Picea abies and Pinus sylvestris wood

was collected from centre-cut commercial-grade dimensional lumber. To obtain tracheid samples,

these cubes were pulverized individually using an Ailence MF-1000 wood pulveriser.” Bad methods

would be “We were given small pieces of wood from the species. The TAs put them in the wood

pulveriser for us.”

Results

Use the results section to summarize your data and report observed trends. Do not discuss

how, why, or what may be the basis for these trends (this material belongs in the Discussion section).

Results should be quantitative rather than qualitative whenever possible. If you are comparing

different groups, your results should compare these groups (example 4). If your results are

presenting a correlation between measurements, include the direction and relative strength of the

relationship (e.g. slope or R2; example 5). When giving quantitative results, always include units.

Example 4: An example of a result that is both quantitative and comparative is, “Mean tracheid

length in Scots pine was estimated to be 2.57mm (standard deviation: 0.57mm). Tracheids of

Norway spruce were, on average, 35% longer, with a mean of 3.47mm (standard deviation: 0.8mm).”

A bad example of a result, that is neither sufficiently quantitative nor comparative would be,

“Tracheids in Scots pine were 2.57. Tracheids in Norway spruce were a lot longer.”

Example 5: A good result describing a correlation is “As distance of the wood sample from the pith of

the tree increased, extractives percentage decreased linearly in Norway spruce wood (slope = 0.14

µLexactives cm-1 ; R2=0.73).” A bad example that relies of qualitative descriptions would be “Distance of

the wood sample from the pith of the tree and extractives percentage were found to be related. The

relationship was very strong.”

Your results sections will also include tables or graphs that display notable trends in your

data. See ‘Writing and Formatting Rules’ below for instructions on how to present and refer to tables,

figures and appendix items. Drawings or photographs can be essential to your results for some

reports, and they may be included in the results section or the appendix at your discretion.

Discussion

Your discussion is where you address your hypotheses (from the Introduction), and

systematically explain possible reasons behind all trends reported in the results section (even if they

are not explicitly included in your hypotheses), as well as limitations of the methods used. Writing the

discussion always involves using additional sources of information (i.e., references from the scientific

literature or from texts, not course notes), statistical interpretation (if any), deductive reasoning, and

logical inference to explain the results that you reported. For each trend a simple procedure is to

make a statement of the trend you observed, then follow this statement with explanations of why you

believe this trend might have occurred (example 6).

Example 6: A good discussion sentence stating an observed trend could be, “Although there is large

variability in the data, Norway spruce tracheids were found to be generally longer than those of Scots

pine.” After making the statement, you could discuss possible explanations for why Norway spruce

produced longer tracheids in this experiment, ideally supported by outside scientific literature e.g.

“An analysis of the wood from seven spruce and pine species found that spruces tend to produce

longer tracheids than pines (Anoulli et al. 1986). This suggests that our trend may be due to broad

differences in growth strategy that have evolved between the two genera, and is unlikely to be

unique to our specific samples.”

In general, a single study cannot prove or disprove a hypothesis. Often we are using a small

sample and assuming it is representative of a broader group. Our measurements are imperfect, and

it is possible that no causal relationship exists between our variables, but rather they are both

related to a third underlying, unobserved variable, or just due to random chance. As such, we can

only use our data to support or refute a hypothesis, rather than prove or disprove it.

Your discussion should also reflect on any limitations or sources of error in your data. Make

notes as you perform your experiment or measurements about what aspects seem more or less

precise or accurate. Unless you can describe very specific errors in your dataset, the rest of your

discussion should treat your results as though they are accurate and generalizable. Saying that “this

trend exists because our data is probably wrong” is rarely a valid explanation.

A discussion should also include some broader implications or applications of your results

i.e., why should we care about these results? We will usually ask you questions in the lab handout

that attempt to draw these connections, and these should be answered within the discussion. While

it is often useful to look into the scientific literature to answer these questions, remember to draw

from your own results as well (example 7).

Example 7: If one of the questions for this hypothetical lab was “Which species’ wood would be more

appropriate for building a house?” a good response would be, “Tracheid length has been found to be

strongly correlated with microfibril angle, a critical parameter of wood strength (Kennedy 1995). As

we found Norway spruce to generally have longer tracheids than Scots pine, it is possible that

Norway spruce has a lower microfibril angle as well and therefore produces better wood for home

construction. This is supported by the results of Lichtenegger et al. (1999), who directly measured

microfibril angle in these species.” A bad response would be “Previous studies have found that

Norway spruce has stronger wood than Scots pine (Lichtenegger et al. 1999). Therefore I would use

Norway spruce to build a house”. While this technically answers the question, it does not relate to

any of the results obtained and therefore would be out of place in this discussion.

Your discussion should end with a brief conclusion. This is a concise summary of the report’s

main findings, why they occurred, and what their further implications are.

References

List in alphabetical order (according to first author's last name) all the sources that you have

cited in your report (see the ‘Writing Rules and Formatting’ section for information on using

references). These references should be, in most cases, peer-reviewed scientific literature or

accepted text books. Do not cite course notes unless you are given explicit permission. If you cite a

source that does not appear in the references, or provide a reference for a source that is never cited,

you will not receive credit for this reference.

Appendix

The appendix contains data and figures that do not belong or fit in the rest of the report. Raw

data sheets, sampling maps, or large drawings are common appendix items. They should appear in

the appendix in the same order that they are referred to in the text. Only include items in the

appendix if they are mentioned in the report and cite them in the same style as tables or figures. To

do this, each appendix item needs to be clearly numbered. Not all reports require an appendix.

3. Writing and Formatting Rules

General Writing Etiquette

Proper paragraph formatting, clear sentence structure, good spelling and grammar are basic

expectations for all assignments. If you are not confident in your writing ability, it is a good practice to

have a friend who is proficient with English proofread your report. Reports must be typed, with size

11 or 12 font, 1.5 or 2 line spacing, and 2.5 cm margins. Do not include a cover page for your report.

Using Latin and Common Names

The first time a species name is used, include the whole Latin name and authority e.g.,

Pseudotsuga menziesii (Mirb.) Franco as well as the common name e.g., Douglas-fir. As long as there

is no potential for confusion, the genus may be abbreviated following the first use e.g., P. menziesii

or the common name may be used throughout the write-up. Latin names (in fact all non-English

words) must always be italicized or underlined. Common names do not use capitals unless they

include proper nouns such as a place or person's name (e.g., black spruce, Sitka spruce and

Douglas-fir are all correct, whereas Black Spruce, sitka spruce and douglas-fir are all incorrect).

Citations and References

Citing and referencing appropriate literature is an essential component of all scientific

reports. We expect you to use peer-reviewed scientific papers in journals for your reports. You can

find these by using search engines such as Web of Science (available through the UBC Library) or

Google Scholar, and access them through the UBC Library. A citation is required whenever you use

information from somebody else’s text or their ideas. A ‘citation’ is the mention of literature in the

main body of your text, whereas a ‘reference’ is the full bibliographic information for a given citation

that is listed in the reference section. You should use the “(author date)” citation style (examples 6,

7). This should go at the end of the sentence using the source information, unless you are referring

to the authors within the sentence (example 7). For reference format, you can use any established

style (e.g., MLA, APA, Chicago) as long as you are consistent within your references. Don’t just copy

and paste references as you find them. They are frequently automatically generated and contain

incorrect or insufficient information.

When citing information, paraphrase the source material (example 8). Do not quote or

directly copy-paste text from references! Improper citation will, at best, lose you many marks on your

assignment. At worst, you could end up facing expulsion from UBC for plagiarism. Directly copying 7

or more consecutive words from any source material is considered plagiarism by UBC standards.

There are some rare cases where quoting information is acceptable. Generally this is when it is an

author’s specific opinion or their exact sequence of words that are relevant, or if they are providing a

technical definition (example 9).

Example 8: Here is a piece of source information, from Kennedy (1995): “There are a host of

properties that determine the quality of wood for different purposes, but the single most important

characteristic is wood specific gravity or relative density.” An appropriate citation using this

information could be:

 Wood quality is affected by many properties, but relative density is the most important

characteristic (Kennedy 1995).

The following are improper uses of this information:

 “There are a host of properties that determine the quality of wood for different purposes, but

the single most important characteristic is wood specific gravity or relative density” (Kennedy

1995).

 There are a host of properties that determine the quality of wood, but the most important is

wood relative density (Kennedy 1995).

 There are a host of properties that determine the quality of wood.

Note that the last 2 examples are explicit forms of plagiarism and may lose you full credit for the

assignment or worse. Even if you are citing a source, you must paraphrase their content.

Example 9: This is an appropriate use of quotation for a reference: “Charles Darwin was among the

first to link domesticated crops and livestock to natural evolution, claiming that he ‘invariably found

that our knowledge, imperfect though it be, of variation under domestication, afforded the best and

safest clue’ to understanding natural selection (Darwin 1859).”

Measurement Units

Report your data using appropriate SI i.e., metric units and always give the units of

measurement for any data when it is first mentioned in your report as well as in every table or figure.

Think carefully about what your measurements mean in reality to determine the appropriate number

of decimal places or significant figures that should be used. Programs like excel will often provide

numbers to 10 decimal places, far more precise than the data that you input. Using these numbers

as they are given is misleading your reader into thinking your results are more precise than they truly

are.

Figures and Tables

Figures such as graphs, drawings and photographs are tools for illustrating written content

that is not otherwise easy to visualize. Tables present values that summarise raw data across

several categories or variables. In your FRST 200 & 210 reports, tables and figures are essential

requirements because formal statistical analysis is usually not required, but we still expect you to

identify and discuss trends.

When creating a figure or table ask yourself what you’re trying to demonstrate to the reader and stick

to the following rules:

 Do not use snazzy graphics–we will not be impressed. We are looking for figures that are

simple, clear and informative.

 All graphs and tables except the first graph of the stem analysis lab (FRST 210) should be

word processed.

 Size matters–don’t use small figures. As a guideline, graphs should be full-page-width. Table

size depends on the amount of data, if the table doesn’t fit on a single page it belongs in the

appendix.

 Figures and tables are separate entities–do not label tables as figures.

 Don’t give graphs a title, even though Excel does by default. This information is provided by

the caption.

 Captions for figures (graphs and drawings) are placed below the figure, but captions for

tables are placed above the table.

 Label each axis of a graph with the variable it represents and the units of measurement.

 Consolidate two or more trends (i.e., datasets) in the same graph if they have identical units

of measurement and values in the same order or magnitude.

 Include a legend if you have more than one trend per graph and make sure that the colours

or symbols are organized such that the reader can draw fast visual conclusions about each

trend.

 Drawings include a scale bar and must be clearly labelled with any parts described in your

report.

 Tables are meant to summarize data. If you are working with means calculated from multiple

measurements or groups, only provide the means. You can include the data used to generate

the means as a separate table in the appendix.

Figures and tables must be cited and explained in the results section. It is best to cite a

figure or table in parentheses at the end of the respective sentence (see example 10). It is never

acceptable to simply list attached figures or to say “see attached figures”. All figures and tables

should be positioned in the report close to the relevant paragraph and in the same order that they

are mentioned in the text, so the reader is not confused trying to find the correct figure.

Example 10: A good citation of a figure would be “Mean tracheid length in Scots pine was estimated

to be 2.57mm. Tracheids of Norway spruce were, on average, 35% longer, with a mean of 3.47mm

(figure 1).” A bad example would be “Figure 1 shows that mean tracheid length in Scots pine was

estimated to be 2.57mm. Figure 1 also shows that tracheids of Norway spruce were, on average,

35% longer, with a mean of 3.47mm.”

Every figure and table must have a caption that includes a number and a brief written

description (in complete sentences) of what the figure contains, but doesn’t describe any trends

(example 11). Captions should be informative enough that you could use them to understand the

figure or table in the absence of the rest of your report. If you use mean values, provide the sample

size used to generate your means (example 11). If you use error bars, say what type of error was

used.

Example 11: A good example of a figure caption might be “Figure 1: Tracheid lengths of mature wood

from Picea abies (n = 5) and Pinus sylvestris (n = 7). Error bars are given in standard deviation.”

Bar Graphs, Line Graphs and Scatter plots: Your chosen graph should be determined by the type of

data on your x-axis. Bar graphs are only used when the x-axis is categorical (e.g., “pines” vs.

“spruces”), but line graphs are required whenever the data are continuous and show change from

one measurement point to the next (e.g., latitude, longitude or a time series such as day of year).

Scatterplots are used to display numerous data points for continuous x-and y-axes. Data points on

line graphs can be connected, but never use a smoothing function in your lab reports. Points in

scatterplots should never be connected with lines, but if you want to show a general trend in your

data, you can insert a line of best fit through the data points (called a trend line in Excel).

4. Useful Hints and Tips

The secret to writing great lab reports: Your first lab reports can be daunting and challenging to

write, but once you’re familiar with the format they will become much easier and obtain higher

marks. We recommend writing the materials and methods section first because it’s simple,

straightforward and familiar to you. Next, analyse your data, create your graphs and write the results

section. Then write the discussion. Finally, although it’s counterintuitive, finish by writing the

introduction. This should make the content of the introduction easier to judge and prevent it from

being too short or long.

Write concisely: Keep sentences fairly short, and don’t use long words if a short one will do. A good

scientific writer will use the minimum number of words possible to clearly state their point, so don’t

use sentences that don’t tell the reader anything meaningful. For example, “This lab was interesting

and helpful for understanding germination better” tells the reader nothing what you learned, so leave

it out. Avoid unnecessary words, e.g., the word “the” can often be deleted with no change in

meaning. After writing a first draft, edit it so that the major messages are maintained but the text is

shortened.

The meaning of ‘significant’: In science, ‘significant’ refers to the outcome of a statistical test. We’re

not doing statistical tests in most of these labs, so it is best to avoid using this term to refer to a

strong relationship in your data, unless you have actually tested whether is constitutes a statistically-

significant difference.

Avoid making overly large scientific inferences: Extrapolation of your data trends to larger scientific

concepts will be required; however, it is not acceptable to do so without adequate supporting

information. For example, applying the concepts learned from observing physiological differences

between Scots pine and Norway spruce to all firs and spruces would be inappropriate. You need to

use valid scientific references to support any conclusions you draw or speculations you make based

on your results. When you are suggesting possible explanations for results, if those are speculative,

write it in a way that reflects the uncertainty, e.g., using words such as “may result from”, or “could

be explained by”. If you want to know more about how to write good scientific papers, there is lots of

information available online. Here is one particularly user-friendly resource.