Scientific Investigation
Lab Report Guide
(A tool used to find reliable answers through collecting data)
10 Parts:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Title or Title Page
Introduction
General Question and Scientific Question
List of Variables
Hypothesis
Materials
Method with Labeled Diagram
Data Results (Table, Observations and Graph)
Conclusion
Evaluation of Conducted Method
1. Title or Title Page
(Title, Scientific Investigation, student
name, class and date)
Title should briefly mention the independent and the
dependent variables. If you include a title page, include an
interesting picture between the title and your name.
The Effect of Artificial Light on
the Growth of Bean Plants
Scientific Investigation
Max Planck, Grade 9
5 September 2016
2.
Introduction
Grade 6: Explain why you are interested in this question.
Grades 7-10:
Part 1: Explain why you are interested in this question and/or
why is answering this question important  How does this
investigation connect to a larger issue?
Part 2: Outline the investigation that you will conduct.
Independent Variable and Dependent Variable should be in
the outline.
Introduction
Artificial lighting is often used in professional greenhouses to
extend the length of day or to increase of the intensity of light
that plants receive. Although light is the energy source for plants,
not all plants grow at the same rate. By investigating the
differences in growth rate, growers can group plants together
with similar light needs and thereby conserve energy.
With this investigation I will investigate how the amount of
artificial light affects the growth rate of Phaseolus vulgaris bean
plants by changing the number of hours of artificial lighting each
plant receives. The goal is to find an optimal number of hours of
light per day.
3.
General Question and Scientific Question
(It may be easier to complete section 4 first and then return to this section.)
General Question: This is main or fundamental question
you are trying to answer.
Scientific Question: This changes the general question to a
more specific question with a clear independent variable and
dependent variable. If possible, write your scientific question
in this form:
What is the effect of ______________ on ________________?
independent variable
dependent variable
*Best if your IV and DV are represented by numbers (i.e.
red is better represented by its wavelength  700 nm)
General Question
What is the optimal amount of light for the Phaseolus vulgaris bean
plant?
Scientific Question
What is the effect of the amount of artificial light on the height of
the Phaseolus vulgaris bean plant after 14 days?
4.
List of Variables
Independent variable: The variable that you
initially change. (left side of data table)
Dependent variable: The variable that you measure
over several trials (your results that you average).
Controlled variables: These are the variables that
you control (keep from changing) so that they don’t
significantly affect your data results. List a minimum of
4-5 (often you will need more) and state how you will
control them.
Variables
Independent variable: Amount of artificial light (hours/day)
Dependent variable: Height of bean plant after 14 days (cm)
Controlled variables:
 Mass and kind of soil (300 g / Toom flower bed soil)
 Time of day when water is given to the plant (8:00 a.m.)
 Amount of water given to each plant (50 ml/day distributed
evenly over surface)
 Compactness of soil (soil pushed down until 1 cm below rim
of pot)
 Seed placement (in center of pot – 2 cm below soil surface)
 Distance of artificial light to opening in the box (3 cm)
 Source of artificial lighting (Halogen 40W)
 Only light from artificial light is allowed to reach plant (each
plant will be placed in an identical cardboard printer paper
box with 8 cm diameter hole cut - top center)
 Time given to the plants to grow (6 weeks)
5.
Hypothesis
Grade 6: Research is optional.
Grades 7-10: Research is required unless specified by the
teacher. Be sure to reference (in-text and bibliography)
any sources you use.
Part 1: Predict the data trend you expect to find on your final
graph.
If possible, write your predicted trend in this form:
I expect that as the ____________ increases, the ___________
will…?
independent variable
dependent variable
*Only include actual numbers if backed by clear evidence
from research like at 0 degrees Celsius, I expect the water
will become a solid.
Part 2: Explain the scientific reasoning behind your prediction.
Whenever possible, try to explain at the particle or cellular
level and think about that the most energy efficient paths are
the most common paths in nature.
Hypothesis
I expect as the amount of artificial lighting increases, the height
of the bean plant after 14 days will increase, since energy is
needed for plant growth and light is a plant’s main source of
energy. Hugh Smith from Cornell University in 2018 found that
bean plants grow on average 4 cm/week in intense sunlight
during 12 hours days. Since artificial lighting is less intense than
sunlight, I expect the bean plants in my experiment to grow at a
slower rate.
Bibliography (place at end of lab report)
Smith, Hugh. Growth of plants in Artificial Lighting vs. Natural Sunlight. Cornell
University. 25 Dec. 2018. www.grofplants.cornell.edu. Accessed 2 Jan. 2019.
6.
Materials:
List in detail (including amounts) what you need for
the investigation.
Materials




7.
12 x bean plant seeds (Phaseolus vulgaris)
12 x plastic pots (10 cm in diameter and 15 cm deep)
250ml graduated cylinder
…
Method with Labeled Diagram: A step-by-step
efficiently-worded description of how you are going to
do your experiment. Make sure to:
a. Describe each variable (IV, DV and CVs).
Your variable list from section 4 and those
included in your method should match.
b. State how many trials you plan to have
(think about the minimum).
c. Include at least one labeled diagram of
your set-up to make it easier for the reader
to follow your method (this can also be a
photo). More diagrams/photos will make
your communication clearer.
d. Include how you will make sure the lab is
safely conducted.
Method
1.
2.
3.
4.
11.
12.
Place 300 grams of Toom flower bed soil in each of the pots
labeled 1-12 and push down the soil until it is 1 cm below
the rim of the pot.
Plant 1 bean seed in the center of each pot 2 cm below
surface of soil.
At 8:00 a.m. give each pot 50 ml of water trying to
distribute it evenly over the surface of the soil.
...
To ensure safety make sure the pots are a minimum of 5
cm from the edge of the windowsill.
Repeat steps 1-10 for a minimum of 3 trials.
Diagram of
Experimental
Set-up 
8.
Data Results (Data Table, Observations, Graph)
(See tutorials for using Google Spreadsheets / Excel in Resources on Veracross)
Data table: Be sure to look for outliers before calculating
your averages. Are outliers included in the averages? Why or
why not? (Grades 9 and 10: Include “Range of Dependent
Variable”)
Observations: Write down notes on anything unusual that
happened during the experiment. These observations will help
later when analyzing your results in your conclusion.
Graph:
a. Choose your graph:
 Scatterplot graph – when numbers (numerical values)
for both x and y axes.
 Bar graph when the independent variable is not a
numerical value (i.e. object  kinds of plants)
 Pie charts are sometimes useful when dependent
variable is a percentage
b. Include: title, subtitles and units.
x-axis: Independent Variable
y-axis: Dependent Variable
c. Plot your data points using average found from your trials.
(Grades 9 and 10: include error bars for the yvalues)
d. Circle and label outliers
e. Do you see a trend in the data points? If so, draw a
smooth curve or line of best fit. The curve/line doesn’t
have to touch all the data points, but it should be as close
to as many points as possible. (Grades 9 and 10: If
linear, include the equation of the line)
Grades 9 and 10: Add "Range of Dependent Variable" to data table.
Range of Dependent Variable (DV)
For example, the values for the
dependent variable are 8.1, 7.8 and 8.2
(5.0 is an outlier, so it is not used since
it is unreliable) and their average is 8.0.
The data point will have a y-value of
8.0, but the error bars will show the full
range of values from 7.8 to 8.2
(lowest to highest value).
Sometimes the previous table does not fit an experiment.
Below is another useful standard table.
Table: Height of Bean Plant vs. Amount of Artificial light
Number Amount Height of Height of Height of
Assigned of
plant
plant
plant
to
artificial after the after the after the
Plant
light
first
second
third
(hours
week
week
week
per day) (cm)
(cm)
(cm)
Height
of plant
after the
fourth
week
(cm)
1
2
3
4
5
6
7
8
9
10
11
12
5.5
6.5
6
8.5
7.5
9.5
3
12
11.5
13.5
14.5
15
1
1
1
3
3
3
5
5
5
7
7
7
Observations
0
0
0
0
0.5
0
0.5
1
1
0.5
0
1.5
1
2
2.5
2
3
2
1
5
4.5
6
5
6.5
1.5
3
3.5
5
5.5
6
3
9
8.5
10
10.5
12
Average
Height of
plants after
4 weeks
(cm)
6.0
8.5
11.75
14.3
1. At the beginning of week three, plant 7 turned yellow and
lost most of its leaves. By the end of week three, all leaves
were gone on plant 7.
2. During week 2 plant 1 accidentally fell over and most dirt
fell out.
3. Only trial 3 plant (receiving 8 hours of light) fit on window
sill, other 2 trials were placed on the floor.
Circle
Outliers
Line of
best fit:
Find the
straight
line or
smooth
curve that
is closest
to the
most
points as
possible
staying
within the
error bars.
9. Conclusion
In this section you will:
1. Answer the scientific question by summarizing your data
results,
2. reflect on how reliable your answer to the scientific
question is by discussing the reliability of your data results
 providing evidence,
3. discuss whether and how your hypothesis was supported 
providing evidence and
4. provide any further scientific explanation needed to explain
your results.
If data was plotted using a scatter plot graph (number values for
IV and DV) and there was a clear line of best fit, include the
following in your summary of the data results:
a. All grades: summarize the trend of your overall data
results (i.e. As the __IV__ increased, the __DV__...)
b. Grades 7 and above:
 Quantitative (in numbers) description of the
relationship between the variables (i.e. For every
extra hour of sunshine per day the rate of growth
increased on average by 0.32 cm/day)
 Qualitative (in words) description of the relationship
between the variables. Linear relationship or not?
What is the pattern of the line of best fit? (i.e. The
plants on average grew more slowly in the beginning
for all, but by the 3 week there was a linear
relationship between the hours of sunshine per day
and their rate of growth growing average 0.32
cm/day)
Grade 10: Describe the graph in further detail by
using the terms: exponential, directly or inversely
proportional, quadratic and, if linear, include an
equation that represents the line of best fit.
Important:
Do not use words like “prove” (that means it is 100%
correct. Is it possible for your data to be perfect?) –
instead use the words “the data supports” that…
Be efficient in your writing by only writing about the most
significant points.
Conclusion (bolded parts are for grade 10)
As the amount of artificial light increased, the height of the bean plant after
14 days increased. The line of best fit is linear with the height of the
plant being directly proportional to the amount of artificial light. For
every extra hour of light per day, the rate of growth increased on average by
0.32 cm/day. The following linear equation describes the line of best
fit and x = amount of artificial light (hours/day), while h = height
of plant after 14 days (cm).
h = 0.32x + 6.9
Only the plant receiving 8 hours of light grew at a much slower rate and did
not fit the linear pattern. This data point is therefore circled as an outlier on
the graph. This outlier may have occurred, since the plants for trials 1 and 2
were not able to fit on the window sill with the rest of the plants.
Consequently, these plants received less additional light from the sun in
comparison causing them to grow less. All other data points are extremely
close to the line of best fit showing that the data is very consistent.
These results partially support my hypothesis. For every extra hour of light,
the plants did increase in height; however, my bean plants grew on average
faster with 12 hours of artificial light per day (5.3 cm/week) than the bean
plants at Cornell University with direct sunlight (4 cm/week). I suspect the
difference in results came from the short 2 week time span of my
investigation. This time span was too short to provide enough evidence to
establish a long term trend.
Plants use photosynthesis to get energy from light. The more light available
for plants to convert into usable energy, the more energy they have to grow.
As a result, the more light a plants receives, the taller the plant will grow,
which is supported by my results.
10. Evaluation of Conducted Method:
Reflect on:
 Problems: What were the most significant reasons
that your data was less than perfect? (Is it possible to
have perfect data?) (minimum 3)
 Suggestions for Improvement: If you had a
chance to conduct your experiment again, describe
realistic changes to your method that could strengthen
the reliability of your data? (minimum 3 and should
answer the above problems)
 Extensions: What other experiment(s) could you
conduct to have a more thorough answer to your
general question? Did other questions arise during the
conducting of this experiment? (minimum 1)
Problem:
Grade 6: Identify the problem
Grades 7-8: Identify and describe the problem
Grades 9-10: Identify, explain and evaluate (see
bolded part below) the problem
Evaluation of Conducted Method
Problem: Halogen lights also generate significant heat and, according to an
investigation done by the University of Edinburgh, heat causes an increase in
plant growth. Therefore, my investigation measured the effect of heat and light
on plant growth -- most likely causing the plant height to be higher than if
only light had been tested.
Suggestion: Use LED lights that produce very little heat when used and make
sure that the plants are in a room where the temperature is consistent throughout
like in a basement. This would allow the numbers of hours of light to be the main
variable of change.
Problem: ….
Extension:
Grades 6-8: To extend this experiment, I would like to investigate how
heat affects the growth of plants by keeping the lighting constant and only
changing the temperature experienced by the plant.
Grades 9-10: I would like to investigate whether desert plants or dark
forest plants are more affected by changes in the amount of sunlight
received, since both categories of plants have evolved under different light
conditions. I would expect dark forest plants to be more sensitive to light
changes, since in a dark forest light is more sparse than in a desert and
therefore any evolutionary advantage to harvest light would be a great
benefit. In desert plants where light is abundant, an evolutionary
advantage is less necessary.
Bibliography (add to end of lab report)
University of Edinburgh. Turning up heat on plants could help grow crops of
the future. ScienceDaily. ScienceDaily, 2 February 2015.
https://www.sciencedaily.com/releases/2015/02/150202105600.htm.
Accessed 23 February 2019.