Unit 1. Experimental Design
Name _______________________
Period________________
Activity 5. Designing Tables to Record Your Results
Recording your results clearly and accurately is a very important in an experiment. Analyzing and understanding
your data is easier when you have recorded your results accurately and in an organized way.
This organization requires pre-planning. Understanding the design of your experiment and what data you need
to record means that you can design a table that is easy for you and others to understand. Not only are there
rows and columns for your measurements or observations (raw data), there are also rows or columns for
summary (calculated or “transformed” values.
Let’s look at a table that was created to collect and summarize data from an experiment whose set up is similar
to our catalase experiment. This is an investigation looking at the growth of plants at three pH levels.
Dependent variable
and its units. Trials are
repeated experiments
Space for 2
plants at
each pH
pH 3
The range of
values for the
independent
variable are in
this column
pH 5
pH 7
Plant #
1
2
Mean
3
4
Mean
5
6
Mean
Trial 1 – mass (g)
Days of growth
0
5
10
0.5
1.4
0.6
1.4
0.55 1.4
0.6
2.4
0.8
2.6
0.7
2.5
0.7
2.3
0.6
2.1
0.65 2.2
Trial 2 (mass in g)
Days of growth
0
5
10
Trial 3 (mass in g)
Days of growth
0
5
10
Recorded dependent
variable
Space for calculated
(transformed) data- the
mean
1. Return to the previous case study (catalase activity) and design a table to hold the data. (Use another
sheet of paper). You first must determine the design of your experiment (see below) and it is best to
sketch out a rough copy of the table first. Use the table above as a starting point to design your own
table.
a. Independent and dependent variables
b. The levels of the independent variable (in this example the levels are pH 3, 5, and 7)
c. Whether or not you are using a control (think about the “job” of the control in your experiment
d. The number of observations within each level of the independent variable
e. Whether or not you will be calculating values that should be a part of the table
f. Whether multiple observations over time (or a starting value) need to be recorded
g. How many times you are repeating the whole experiment (trials)
Create the table using DOCS or SHEETS and upload in Google Classroom.
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Unit 1. Experimental Design
Name _______________________
Period________________
MORE PRACTICE:
Case study 2. Carbon dioxide levels in a respiration chamber.
A data logger was used to monitor the concentrations
of carbon dioxide (CO2) in respiration chambers
containing five green leaves from one plant species.
The entire study was performed in conditions of full
light and involved three identical set-ups. The CO2
concentrations were measured every minute, over a
period of ten minutes, using a CO2 sensor. A mean
CO2 concentration (for the three set-ups) was
calculated. The study was carried out two more times,
two days apart.
What are your dependent ___________________ and independent variables? ___________________
What is the range of values for the independent variable and how many different values are you measuring?
Is there a control? _________
If not, what would you use as a control?
How many observations (measures) will you make (record) for each of the respiration chambers?
How many respiration chambers are present? Do these chambers represent replication within an experiment or
a different experiment? Explain why.
How many times are you repeating the experiment?
Discuss with your lab group what you believe will happen to the CO2 levels (think about the equation for
photosynthesis). Predict your result by sketching a graph of what you predict will happen. Be sure to label axes,
create a meaningful title, and select an appropriate graph. Use graph paper (one graph for your group).
PROVIDE JUSTIFICATION FOR YOUR ANSWER (write a sentence or two). Put first and last name of all group
members on the graph.
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