IB ESS -How to write a Good Lab report

GURU CHARAN KUMAR IB ESS IA 2013
1 | P a g e
ENVIRONMENTAL SYSTEMS & SOCIETIES IA
2012
WRITING A GOOD
ES&S LAB REPORT
ESS INTERNAL ASSESSMENT
Subject Teacher: Gurucharan

GURUCHARAN KUMAR IB ESS IA 2013
PLANNING LABS
For a planning lab you are required to have the following sections:
AIM
The aim must reflect the research question and should be engaging
INTRODUCTION
 An introduction sets the scene for the whole of the report. It only needs to
be 2-3 paragraphs long and should be about the topic being investigated.
 For example, if you are investigating the influence of Nitrogen on plant
growth, you would write a brief account of what is known about the effects
of this nutrient on the growth of plants. In-text referencing is usually
required as this section is not only your work.
RESEARCH QUESTION:
 The research question needs to be specific and focused.
 You need to indicate the variable chosen for the investigation. Think about
this very carefully. A poor question would be “How does phosphorous
affect plant growth”.
 A good research question would be “How does changing the concentration
of available phosphorous in irrigation water affect the growth of the marine
grass Sporobolus virginicus?”.
 If you want to see how professional scientists write research questions just
look at the titles of articles in journals (on the web) such as Science, Nature,
PLOS and Ecology & Society.
HYPOTHESIS
An hypothesis (not strictly required but this will help focus your work)
Not all investigations will have a hypothesis – but – most will, and they are a very
good way to focus your thoughts and ideas.

 It should be quantitative if at all possible.
 If there is a clear mathematical relationship between the Independent Variable
(IV) and the Dependent Variable (DV) this needs to be stated in your
hypothesis.
 A scientific justification of your hypothesis
 You must show that you have done some research on the subject through the
justification of your hypothesis.
 You will need to provide reasons for why you think your hypothesis will be
the outcome – this is not a personal view, it is a view based on sound
scientific judgments based on your research.
 You should cite sources listed in your bibliography. The justification
(scientific explanation) may require discussion of equations, general
principles, laws and published examples.
VARIABLES:
Variables are factors that may affect the outcome of your experiment. They are
measurable factors, not pieces of equipment. Do not use the word “Amount”. It is
not specific enough – terms like mass or volume are better.
1. Independent variable: Independent Variables are changes that occur in an
experiment that are directly caused by the experimenter (you.).
2. Dependent variable: Dependent Variables are changes that occur due to
independent variables. It is what you are measuring or trying to find out.
3. Controlled variables: A Controlled Variable is anything else that could
influence the dependent variables..
4. Uncontrolled variables: Usually climate factors that you try to keep the
same for each sample.
For example, we can set up an experiment in which we measure time needed for an apple to fall
from different heights. First we go to the first floor, release the apple and measure the falling
time. Then we go one floor up, repeat the measurement, and so on. In this experiment, the height
from which we were releasing the apple, we can consider as independent variable, and the
falling time as dependent variable, because the time depends on our freely selected height
A clearly laid out section on variables
This is where you have the greatest potential to lose marks in the Planning
Criterion. Two of the 3 aspects are focused on variables.

Independent Variable (IV) – name it, include units of measure, and describe it.
Include a statement of the range of the data values that will be tested. If necessary
explain the IV and what is actually measured – e.g. you may be measuring
productivity in g/m2
/day and converting that into tonnes/year in your graphs.
Dependent Variable (DV) – name it, include units of measure, and describe it. If
there is a mathematical relationship easily understood in an equation give this
here. Explain how you derive the DV if it is not directly measured – e.g.
Sustainable Yield would be derived from data on the total population and birth
rates (recruitment).
Controlled or Fixed Variables – List (name) the variables that you will actually
control. Provide a brief description of each variable and the parameters of the
control (how you will control the variable)– e.g. ‘Light will be controlled using a
fixed intensity of light (100W) and a daily rhythm of 12 hours of light and 12
hours of dark’. In your description include information on why you need to
control the variable. Be specific and focused.
Do not list those things you cannot control or fix (e.g. atmospheric conditions
outside when you are in the field) but you should be able to account for any
influence of these uncontrolled variables on your data in the discussion and
evaluation sections of a lab report.
PROCEDURE
Materials
Provide a list of all the equipment used in the investigation. This should include
the quantities required, the sizes of the different beakers etc, the chemicals
required (named) and quantities and types of materials (e.g. distilled water, tap
water). Be specific but don’t be pedantic.
Diagram or photograph of your experimental set-up
You can include a diagram or a photograph of the experimental set up if you find it
necessary. Please remember that if you use a picture it is referred to as Figure #
(with a descriptive title) and you must discuss it in the text somewhere. Otherwise
it is just a picture in your lab report.
Procedure
This is a numbered list of clear, exact steps to follow – described in a brief and
focused manner. Nobody likes reading this part, so be clear and brief. The steps
in the experiment should either be self-evident or briefly explained. You should
aim to describe a method that would enable someone to carry out the experiment.

♠ Explain how to change or manipulate the IV (and measure giving
units)
♠ Explain how to measure the IV (units and errors)
♠ Explain how to control the CV/FV. The IB states that “The method
should include explicit reference to how the control of variables is
achieved”. For example, if you are weighing samples you need to
state that you collected the data using the same balance every time.
Or you controlled temperatures by using a water bath set at 24°C.
A Raw Data Table to show how you would collect your data
A clear, easy to follow method is necessary to achieve a “2” on Aspects 2 and 3.
Think about method you have seen and what information you like to have!
Someone (who has not done the experiment before) should be able to follow your
procedure and obtain similar results.
The following features contribute to writing a good method.
A. The method can be written as instructions like a recipe
B. Do not begin with “Gather all of the materials” … it is kind of a given that
you will do this!!
C. Use numbered steps (rather than paragraphs).
D. Use a diagram if possible to show how to set up any equipment. Then you
can say “Set up the equipment as shown in the diagram”. This would save
you writing a lot of words.
E. Specify what will be measured (and the units to be used)
F. Include details of how you will measure values
REFERENCES/BIBLIOGRAPHY
A full set of references in the correct format (MLA is preferred). These
must be consistent and done in alphabetical order. In text referencing must
follow a clear and unequivocal standard.

RAW DATA refers to the values obtained from the measuring instruments
exactly as they were shown. Once you do any addition, subtraction,
multiplication or division then it becomes PROCESSED DATA
Example for Step 3f.
Controlled
variable
Method to control the
variable
Temperature
at which
reaction
occurs
The test tubes in which
the reaction occurs will
be placed in a water bath
set to 40 C for the
duration of the reaction.
Duration
(time) of the
reaction
The reaction will be
allowed to proceed for
300 seconds. This will be
timed using a stopwatch
( 0.1seconds).
A good format is “To determine how [the
independent variable] affects [the dependent
variable] in [the context of your
experiment].”
e.g. To determine how acid rain affects the
germination in common beans
e.g. To find the effect of age and gender on
the perception of global warming of
Ugandans.
Number of Values
If you are looking for a correlation, at least 5
different values are needed (the more the
better).
If you are comparing two different situations,
3 values will be sufficient.
Range of Values
You may need to do some research to
help you decide.
E.g. if testing acidic rain solutions then
you would want to test values around
5.6pH. If you are investigating chemical
spills in you might want lower pH
values

CHECKLIST FOR PLANNING LABS
Aspect 1: Defining The Problem And Selecting Variables
□ I have identified a focused problem or a specific research question. I have
done this by stating a clear aim, a clear hypothesis, and clearly defining the
variables.
□ I have identified and stated the independent variable and the dependent
variable, and I have listed the controlled variables
Aspect 2: Controlling Variables
□ I describe a method for the effective control of the variables. In particular, I
describe how the independent variable is manipulated and how the
controlled variables are maintained at constant values
□ I list all the apparatus and materials used, including the volumes of tubes
and cylinders, the concentrations of solutions, the model and manufacturer
of any complex apparatus, etc.
□ I state the level of precision of the values for the independent variable
□ Any standard methods that I use are fully referenced in a footnote or in the
references
Aspect 3: Developing A Method For The Collection Of Data
□ I describe a method that allows for the collection of sufficient relevant data
□ The data gathered enables the aim, the research question or the hypotheses
to be adequately addressed
□ The data gathered enables an evaluation of the reliability of the data
□ The sample size should be adequate to allow a reasonable statistical analysis
of the data (for calculating the standard deviation, at least five items per
treatment)
□ An adequately broad data range is considered
□ An adequate number of data values within this range are considered

Data Collection & Processing Labs
This is the criterion that causes the fewest problems for students and if you follow
the guidelines of the rubric closely you can score well. This is the section of a
scientific publication that would be called the RESULTS. There are very specific
expectations in this type of lab – most of which are logical and easy to understand.
The DCP (Results) section is arguably the most important part of any research
report as this is where you bring together and report your findings. When done
properly, this section will present your results clearly and in a way that shows that
you have organised your data and carefully considered the proper analysis.
If you are doing a DCP lab without a planning section you will need to include the
following sections that would normally occur in a Planning lab in more detail.
TITLE – same as Planning lab
INTRODUCTION
o Introduction – same as Planning lab (be brief)
o Research question – usually included but should be brief and must be
different from that provided by your teacher.
o Hypothesis – clearly stated with a scientific justification. Be brief,
not as detailed as for a Planning Lab
o Variables – this section should be clearly laid out – show you
understand the variables. Not as much detail as a Planning Lab – be
concise.
PROCEDURE – if the procedure is provided, make a brief reference to it
and explain any modifications. No detail required. No data table required
here.
For DCP labs you are not directly assessed on any of the preceding information but
it is important to have a brief and focused introductory section because it allows
the examiner to understand the context of the data AND that you know what it is
that you are doing!

DCP labs comprise the following:
DATA TABLES
There are 2 types of tables –
Raw Data Tables which comprise the data collected in the field or lab, and
Processed or Final Data Tables which are a synthesis of the data in the Raw Table.
Final data tables summarise raw data, show any data transformations performed
and the results of any statistical tests. You must include both.
1. All tables must have a number and a title. E.g. Table 5: ANOVA analysis
of the association between the winter catch rate for mudfish Gala tribolius
and four habitat parameters. In science there is a convention that the title
goes above the table.
2. In investigation where there is pooled/group data, you need to identify your
own data clearly.
3. All tables must be numbered in sequence so that you can refer to them easily
in the text.
4. All columns in tables must have a heading and units.
5. IV is in the first column and recorded data in subsequent columns across the
rows
6. Errors (and uncertainties) where applicable should be included in a column
heading or a separate column
7. Tables must show the quantitative data collected. All quantitative results
must be recorded to the appropriate level of accuracy and must be recorded
consistently (sig.fig and dec.places).
8. MUST have the qualitative observations included either in a specific column
or as notes appended to the relevant table.
9. MUST include Fixed Variable data, usually in the Raw Data table but can
be in a table of fixed values.
10.Within a column all the data must be shown with the same number of
decimal places or significant figures.
11.Decimal places in the processed data must match the raw data. You cannot
have processed data to 3 decimal places when you collected the raw data
rounded to one unit!
12.Where you included statistical data you should indicate those statistical
values that are significant and those that are not (and at what level e.g.
P<0.5).
13.Tables must be neat, logical and organised.

CALCULATIONS
1. The demands of the ESS syllabus on the student with regard to statistical
analysis of data are minimal.
2. Students are expected to be able to go beyond simple arithmetic calculations
such as means and aggregated totals. You should however, know how to
use or interpret simple descriptive statistics such as the mean, median,
mode, range, frequency, percentages, ratios, approximations and reciprocals.
3.
You are required to use standard notation, e.g. 3.6 x 104
.
4. You should collect data (or plan to) for at least 3 trials per treatment for any
investigation. In ecological data it is better to have at least 5 trials.
5. You should be able to apply basic statistics such as:
a. Standard Deviation
b. Student’s T-test
6. You need to show (and explain briefly) all calculations that are done on the
raw data. You are only required to show one example of each calculation to
show that you understand the calculation. This is important for the 2
statistical tests given above.
7. If you use an equation such as Simpson’s Diversity Index you must show
one example calculation for this formula.
8. Take care to use the correct number of significant figures and/or decimal
places in all calculations.
GRAPHS
Graphs show trends or patterns in the data. Be sure to choose the correct type of
graph and allocate enough page space for it in your lab report.
1. Every graph should have a number and a descriptive caption or title.
Numbering must be sequential. In science that convention is that the
caption goes below the graph.
2. Graphs should be printed large (at least half the page).
3. Remove the title provided by Excel and move the key to under the x-axis.
This gives you more room on your graph.
4. Scale the graph axes appropriately. The axes should go beyond the points
on the graph
5. Label all axes and include units
6. Keys should be provided either in the title, on the graph or as a note attached
to the graph.

Independent variable/ units
7. Decimal place values on the axes of the graph must be consistent with the
data in the tables.
8. Use error bars where appropriate. If error bars are too small to be seen, this
should be explained in the graph title/caption with quantitative examples of
the error bar size.
9. Present basic graphs first (i.e. show the fundamental data first) and then (if
appropriate) present combined data projections, transformations and other
complex graphs.
10.If using Excel use only graphic presentation options that print well in black
and white. Do not use dark coloured backgrounds with coloured lines.
Black and white graphs with distinct data points are best.
11.Show gridlines at an appropriate scale.
CONCLUSION & EVALUATION:
You should keep your statements of important findings brief and you should
only include results here – there is no discussion of the actual results. For
example, “Mean summer water depths were only 3.6cm in areas with
mudfish, compared to 39.5 cm at those sites with no mudfish”.
Refer directly to your tables and graphs in the text and you can highlight
important differences between your results and any published results (you
should not discuss these, merely highlight them). For example, “The results
for the analysis of total dissolved solids (TDS), dissolved oxygen (dO) and
secchi disc depths (cm) are given in Table 3.1. These were similar at all
tests sites, in contrast to the findings of Miller (2001) who found that TDS
was higher at sites with mudfish than at those sites without mudfish”.
Include units for all data references, e.g. “Total catch rates for all sites are
similar (geometric mean 0.70 fish per trap per night: Table 5.3)”.
Dependent
variable/ units

These bridging statements and references to your tables and graphs make it
easier for you to discuss your results later and for the reader to understand
that you know what is going on in your investigation.
Quantitative data – numerical values obtained from the measuring instruments (e.g. temperature,
mass etc) or by other means e.g. counting
Qualitative data – non-numerical observations. Other observations made during your experiment
that may have a bearing on the conclusion or help to explain patterns and trends (or the lack of!).
Examples include changes in colour, texture, size etc
Any other observed sources of error should also be recorded.
CHECKLIST FOR DATA COLLECTION AND PROCESSING
Aspect 1: Recording Raw Data
□ I have recorded my data independently
□ I have data which is quantitative (numerical)
□ I have chosen a suitable format in which to record the raw data
□ The variable that is measured or recorded is clearly stated (e.g. in the
column heading in a table)
□ The units are given for every variable (e.g. in any column headings)
□ An indication is given of the uncertainty of measurements (e.g. in any
column headings)
□ A complete and descriptive title is given to any table that is used
□ The same level of precision (number of decimal places) is used for all the
items of a variable
Aspect 2: Processing Raw Data
□ I have decided on a suitable manner in which to process the raw data, so that
I may fully test the hypotheses or fulfil the aim (this may involve
mathematical processing, statistical analysis, or transforming the data into a
suitable graphical representation)
□ All of the raw data has been processed to a suitable extent
□ The raw data has been processed correctly
□ Any raw data plotted onto a graph includes a line of best-fit where
appropriate

Aspect 3: Presenting Processed Data
□ I have decided upon a suitable format in which to present the processed
data.
□ There are clear, unambiguous headings for calculations, tables or graphs
□ Any graphs have appropriate scales, labelled axes with units and accurately
plotted data points with a suitable best-fit line or curve
□ The data has been presented so that all the stages to the final result can be
followed
□ Metric/SI units are included for the final results
□ The final results are shown expressed to the correct number of significant
figures and/or decimal places
□ The uncertainties and errors associated with the raw data have been taken
into account and this is shown in some manner (e.g. error bars may be used,
as appropriate)

DISCUSSION, EVALUATION & CONCLUSION LABS
1. This section is a real challenge – it is where you are required to show that
you can apply your knowledge, interpret your findings and propose further
work. In other words, you have to show that you know what you have been
doing.
2. In this section of a report you are required to interpret your results in the
context of the specific questions you set out to answer in the investigation.
3. You should place your findings in the framework of any broader relevant
issues (often with reference to findings or data from published sources).
4. You must be prepared to discuss any unexpected or conflicting results.
5. Once you have interpreted the data and given an account of your findings
(discussion) you then develop a concluding statement that directly addresses
your research question and hypothesis and how/why the results support or
do not support your hypothesis.
6. The evaluation section of the report is often difficult. You are required to
critically evaluate any problems with your study design, unexpected and
conflicting results, how and why these results may have come about and to
propose realistic improvements or extensions to the investigational
procedure.
7. The sequencing of the following sections follows the rubric – Discussion,
Evaluation, Conclusion. If you think that it is more logical to do the report
in a different sequence by all means do so. It is sometimes easier to do –
Discussion, Conclusion, Evaluation.
DISCUSSION:
This is the interpretation of your results. Support your statements with
reference to Tables, Graphs and data in the DCP results section. Some of
the details that you should include are:
o A discussion of the errors/anomalies in the data
o Any random errors and how they affected your data
o Any systematic errors and how they affected your data

o A discussion of the precision and accuracy of the data. This should
include an overall statement about the quality of the results and how
confident you are in your results
The discussion explains the relevance of the results of the investigation.
Do not introduce new results in this section. You should have highlighted
the relevant data in the DCP section.
You can, however, provide supporting or contrasting results from published
studies but these must be cited using in-text referencing.
Your discussion needs to be clear and well reasoned. In other words, it
should have a logical and progressional structure. For example, Graph
1/Table 1, progress to Graph 2/Table 2 etc – building up the information to
support your conclusion.
You discussion needs to show a broad understanding of the context. You
need to have done some research beyond your direct investigation. This
may be as simple as stating how the results support what has been discussed
in class/in your textbook.
You need to be sure to explain the implications of your results in a broad
context. For example, if you are studying the effects of pH on plant growth,
how do your findings fit in with what is known about acid rain.
EVALUATION
This section of the report causes considerable problems for students. Look to do it
in a structured, focused way and it will be a lot easier. The purpose of this section
is to identify any problems, weaknesses, limitations or errors in your experiment
and then to make recommendations as to how to improve the process the next time
you do the experiment. It is a section where you are saying “watch out for this”,
“fix that” and “this could be better”.
The evaluation should include a brief discussion of the weaknesses, impacts and
improvements in the following areas:
The experimental design. The focus here is the variables – were they
appropriate, could they be better controlled, were the units of measure and
the errors appropriate to the experiment.
The equipment you used. What problems, errors, corrections,
standardisations etc.
The method/procedure you designed. This is where most of the comment
usually comes in and should include a careful evaluation of:
o Good procedures, bad procedures and improvements
o How to improve the control of variables
o How to reduce random errors

Your use of time. Be brief and to the point – don’t spend 3 paragraphs
confessing to not doing the work and how you are going to be better next
time! This is about how you could improve your use of available time by
improving the methodological approach not your personal organisation.
It is suggested that you consider using a table, horizontally across the full page and
discuss these four points under the following headings.
WEAKNESS/LIMITATION IMPACT ON
RESULTS
IMPROVEMENT
Outline the actual problem
that you have identified and
how it came about. Be
quantitative (use
numbers/data) to illustrate the
problem
What did it mean in
terms of the results that
you have collected. If
you need to point out
the error/problem in a
graph or table.
How are you going to
fix the problem. Be
realistic and specific.
This does not include
saying “buy better
equipment’, “be more
organised”. . If
appropriate, state if the
improvement is going to
improve accuracy,
precision, reduces
random error etc.
.
Describe improvements for each identified weakness
This section deals with Aspect 3. Suggestions for improvements should be
based on the weaknesses and limitations identified in Aspect 2.
For each improvement ensure that:
a) Modifications are specific (numerical if possible). “Next time we should
work more carefully” is not acceptable.
b) Modifications are realistic – they can be achieved within the constraints of
the timetable, school setting and budget.
c) Improvements are not overly simplistic or superficial – you need to
demonstrate that you are a student at a Diploma level!
CONCLUSION
Your discussion should be built up in such a way to support your conclusion that
should, ideally, come at the end of your discussion. The concluding statement

does not have to be long or particularly detailed but should address your research
question and your hypothesis. Your discussion serves as the scientific explanation
of your conclusion and so you do not need to repeat much here – it is a synopsis of
your findings and how your findings fit in with your research questions and
hypothesis.
In order to have a complete based on the rubric (Aspect 3) your conclusion should
include:
Restating the research question and the predicted hypothesis
A statement of what the results mean, particularly the relationship between
the IV and the DV
A statement of whether the results support the hypothesis or not.
A brief statement of why this relationship exits (support or not). You can
bring in outside research to assist your interpretation.
Use your results to justify your conclusion (explain
how your results support your conclusion). See
example to the right 
To achieve at the highest level for this aspect you should make sure that:
a) Conclusions are truthful and based on the data. Don’t try and twist your
results to fit a hypothesis or expected outcome.
b) The conclusion is clearly related to the Aim.
Bad example
The results show that the concentration of sugar affects the rate of respiration. As the sugar
concentration increased so did the rate of respiration.
GOOD example
We can conclude that there is a positive, linear relationship between the concentration of sugar and
the rate of respiration. The correlation coefficient of 0.9 indicates that it is a strong relationship.
The trend line in Figure 1 shows that there
is a positive, linear relationship between the
concentration of sugar and the rate of
respiration. The correlation coefficient of
0.9 indicates that it is a strong relationship.

c) The conclusion provides a thorough description of any trends or patterns
CHECK LIST FOR CE
Aspect 1: Discussion and Review
□ I have discussed my results in a logical sequence, from basic findings to
more complex interpretation of results.
□ I have included references to graphs, tables, diagrams and literature values
in my discussion
□ I have included a discussion of the broader context of the results based on
external research
□ I have included a discussion the implications of my results based on
published research and/or current understanding
□ I have structured the discussion to support my conclusions in a clear and
focused manner
Aspect 2: Evaluating Procedures
□ I have commented on the design and method of the investigation
□ I have commented on the quality of the data
□ I have listed the weaknesses of the study
□ I have assessed the importance of each of these weaknesses
□ I have commented on the precision and accuracy of the measurements
□ In evaluating the procedure, I have specifically looked at the variables, the
processes, the use of equipment and the management of time
□ My suggestions for improvements are based on the weaknesses and
limitations identified.
□ As appropriate, I address modifications to the experimental technique and
the data range
□ The modifications that I propose are realistic and clearly specified
Aspect 3: Conclusion

□ I state a conclusion which is based on a reasonable interpretation of the data
□ If any hypotheses are being tested, I have stated whether the data supports
these hypotheses
□ I give a justification for my conclusion
□ As appropriate, I compare different graphs, or describe the trends shown in
my graphs
□ If I am measuring an already known and accepted value, I have compared
my value with that in a textbook, in order to assess the validity of the result.
□ I fully reference any literature that is quoted.
GENERAL ISSUES
All lab reports used for Internal Assessment (IA) must be printed out on A4
paper with at least a 20mm margin on the left of the page. It is better to
have 20 mm margins both left and right as this allows space for comments.
Stick to a basic font (Arial, Calibri, Times New Roman) that is large enough
to read (10 or 12pt).
Try not to write in the first person. This means that you should try not to
write using “I”, “We”, “Us” etc. Use the 3rd
person and in passive form.
For example, don’t write “I think it is going to jump…..”, use something
like “It is believed that….”, “It was observed that….”, “It was found
that…..”.
You can also cite outside sources as a way of avoiding the first person.
“Based on the findings of Collar & Webb (2008), it is predicted that…….”
Figures (pictures, diagrams and photographs), Tables & Graphs must all
have a specific number and have a clearly understandable and focused
descriptive title. For example, don’t write “Graph showing data from Table
on next page”. Use something like “Graph 3: Line graph showing the
relationship between the length of bean sprouts and the application of
varying concentrations of phosphorous over 10 days”. More details are
given in the section dealing with Data Collection & Processing.
The first 2 pages of the lab report should be:
o The rubric/s being assessed.
o The instruction sheet for the lab.
Prepared

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IB ESS -How to write a Good Lab report

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