This format can be followed using the color convention showed
Definition
Example
Aspect to evaluate
THE VICTORIA SCHOOL
SCIENCE DEPARTMENT
¿HOW TO DO A LAB REPORT?
7th - 8th Grade
INQUIRING AND DESIGNING (CRITERION B):
1. Research Question: Describe a problem or question to be tested by a scientific
investigation.
How does the photosynthesis process affect oxygen (O2) and carbon dioxide (CO2)
concentrations?
Aspect i. Describe a problem or question to be tested by a scientific investigation
2. Hypothesis: Outline a testable hypothesis and explain it using scientific reasoning.
A hypothesis is a prediction or an “educated guess” to answer a part of the
Research Question.
In the photosynthesis process carbon dioxide (CO2) concentration decreases while
oxygen (O2) concentration increases.
Aspect ii. Outline a testable hypothesis and explain it using scientific reasoning.
3. Variables and data collection
A. Identify which factors could possibly affect the experiment
Independent Variable
Dependent Variable
Control Variable
Is the part of the
experiment being tested,
that is controlled and
changed (manipulated) by
the person doing the
experiment.
Is the part of the
experiment that is affected
by
the
independent
variable, and is observed
and/or measured. The
dependent variable is
what you don’t know
before
doing
the
experiment, and usually
makes most of the “data”
Are
parts
of
the
experiment
that
are
maintained
constant,
factors that if changed
may affect the other
variables.
Time
that you record
Oxygen (O2) and Carbon
dioxide (CO2)
concentrations
-Temperature
-Humidity
-Plant quantity
-Sunlight
B. Data Collection: Explain how the dependent variable(s) will be observed or
measured. Include an idea of how many observations or measurements will be
required, and what instruments will be used.
Oxygen (O2) and Carbon dioxide (CO2) concentrations were measured using the
Vernier sensors and as an interface the Labquest which records the quantity of those
gases in a closed environment. One graph was made of time vs. Oxygen (O2) and
Carbon dioxide (CO2) concentrations, and data was recorded each 10 second for 60
seconds. The rate of the experiment was 0.1 sample/second.
Aspect iii. Describe how to manipulate the variables, and describe how data will be
collected.
4. Design the Experiment:
A. Make a list of materials used.
-Labquest
-O2 Vernier sensor
-CO2 Vernier sensor
-Leaves of different plants
-Sample bottles
B. Prepare a step by step procedure that explains how the independent variable(s)
will be manipulated, control variables will be controlled, and dependent
variable(s) will be observed and/or measured.
1. Pick up enough fresh plant leaves from the park.
2. Make the experiment assembly which includes turning on the labquest,
connecting sensors, introducing leaves to the sample bottle and connecting
them to the sensors.
3. Establish the graph parameters on the labquest (Time= 60 sec and Rate= 0.1
sample/sec)
4. Record data
Aspect iv. Design scientific investigations.
DATA PROCESSING AND METHOD EVALUATION (CRITERION C)
1. Data Collection and Processing: Record all observations and/or measurements (raw
data) in organized well-labeled tables (Include correct column headings, units and
uncertainties).
Time (sec)
Concentration O2 (ppm)
± 1% of the reading
Concentration CO2 (ppm)
±10% of the reading
10
202,000
344
20
204,000
343
30
208,000
329
40
211,000
322
50
212,000
317
60
216,000
311
UNCERTAINTIES
CO2 Sensor
O2 Sensor
±10% of the reading
± 1% of the reading
Show examples of any calculations and organize processed data (calculated or
reorganized) in another table. Make graphs if it is necessary and explain them
briefly.
The graphs show the relationship between the independent variable (Time) and the
dependent one (Oxygen (O2) and Carbon dioxide (CO2) concentrations in ppm). The
concentration tendency on the graphs show that Oxygen (O2) increases and carbon
dioxide (CO2) decreases as the time passes.
Aspect i. Present collected and transformed data.
2. Data Analysis and Results:
Use scientific reasoning to explain what your data means.
- Oxygen concentration (O2) increases with the increase of time. It has a
maximum value of 216,000 ppm at 60 seconds and minimum of 202,000 ppm at
10 seconds.
- Carbon dioxide concentration (CO2) decreases with the increase of time. It has a
maximum value of 344 ppm at 10 seconds and minimum of 311 ppm at 60
seconds.
- Control variables such as temperature, humidity, quantity of leaves and sunlight
were not measured.
Compare the obtained results with theory.
-
-
The initial concentration of oxygen (O2) is considerably greater than the carbon
dioxide (CO2) one, this data agrees with theory because the standard values for
these gases are approximately between 300-400 pm for carbon dioxide (CO2)
and for oxygen (O2).
Results agree with theory because in the photosynthesis process the plant
consumes carbon dioxide (CO2), water and sunlight to make its own food so
carbon dioxide (CO2) concentration should decrease, and produces glucose and
oxygen (O2) so oxygen should increase.
Aspect ii. Interpret data and describe results using scientific reasoning.
3. Results and Conclusions: Compare your data to your hypothesis. Explain how well
your results support the hypothesis. In which ways does the data show that your
hypothesis is true? False?
The hypothesis is valid because as the results demonstrate in the photosynthesis
process carbon dioxide (CO2) concentration decreases while oxygen (O2)
concentration increases.
Aspect iii. Discuss the validity of a hypothesis based on the outcome of the
scientific investigation
4. Evaluation: Explain how well the experimental method worked to test the
hypothesis. How well did the investigation go? What problems happened during the
experiment? Find out limitations. Are results reliable?
-
The method used allows determination of the relationship between the
photosynthesis process with how Oxygen (O2) and Carbon dioxide (CO2)
concentrations change.
-
The sensors register quantitative data, and its reliable data.
-
Since the uncertainty of the CO2 sensor is very high (10%) compared to
the O2 sensor (1%), this data is less reliable.
-
Possible mistakes of the experiment could include the lack of control and
measurement of control variables that might affect or change the
dependent variable.
-
Sometimes the interface becomes blocked, so the experiment takes too
long.
Aspect iv. Discuss the validity of the method
5. Improvements: Explain what you would change if you were to do the experiment
again. Would you change the method? Would you make more observations or
measurements? Why?
-
Control variables should be measured in order to assure they remain
constant.
-
Using fresh leaves, with a green color gives better results.
Aspect v. Describe improvements or extensions to the method
Depending on the scientific investigation, Criterion A (Knowing and understanding, Aspect
i. describe scientific knowledge, Aspect ii. apply scientific knowledge and understanding to
solve problems set in familiar and unfamiliar situations, Aspect iii. analyse information to
make scientifically supported judgments) and Criterion D (Reflecting on the impacts of
science, Aspect i. describe the ways in which science is applied and used to address a
specific problem or issue, Aspect ii. discuss and analyse the various implications of using
science and its application in solving a specific problem or issue, Aspect iii. apply scientific
language effectively, and Aspect iv. document the work of others and sources of
information used) may also be graded.