Biology I
SEPTEMBER 8, 2014
CHS
Objective: 1c:
Apply the components of scientific processes
and methods in classroom and laboratory
investigations (e.g., hypotheses, experimental
design, observations, data analyses,
interpretations, theory development). (DOK 2)
Focus Question:
What does an experiment consist of?
DO NOW
Identify the following vocabulary words below:
1. A set of steps used to test a hypothesis
2. A factor that is changed during an experiment in order
to test its effect
3. The variable used to produce an effect
4. The measureable change that occurs because of the
independent variable
Performing Scientific
Experiments
Setting Up Experiments
Section 2.2
Review Scientific Method Steps
Scientific Method Song
Words to Know
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Experiment
Data
Quantitative Data
Qualitative Data
Control Group
Experimental Group
Bias
Unbiased
Placebo
Constants
Variable
Independent Variable
Dependent Variable
What is an experiment?
An experiment is set of steps that are
performed to collect data which van be used to
either prove or to disprove a hypothesis.
Questions to be considered when
designing and experiment:
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What data should be collected and how?
How many groups will be used?
How many subjects per group should be used?
What will be the control group?
Will there be a placebo used?
What are the important constants?
What is the independent variable?
What is the dependent variable?
So what is Data?
• Data is any information gathered during an
experiment.
• The two types of data include:
a. Quantitative data- measured data such
as length, mass, pH, temperature, or
time of day.
b. Qualitative data- data recorded in most
experiments; also known as descriptive
data; Examples: color, odor, taste, feel, or
any other describe quality
What kind of data should a scientist
record?
• Many kinds of information can be recorded
during an experiment.
• The only data that should be collected in an
experiment is the information that can be
used to prove or disprove the hypothesis.
• The scientist must decide which information is
important to record and which isn’t.
How many groups should be used in
an experiment?
• There are two types of groups:
a. Control Group- serves as a standard for
comparison
b. Experimental Group- Experimental
groups receive the same treatment
except for the one element being tested
(Independent Variable).
Example:
• A research scientist believes she found a new
drug that will cure cancer. The scientist will
have a strong belief ( a bias) that this drug
works, and her belief (bias) may influence her
own experimental results.
Bias in an Experiment
When doing an experiment, a scientist should
be unbiased, or impartial.
 A bias is a belief or a preference for a specific
outcome.
 Being unbiased means the person does not le
his or her personal opinions affect the results.
Placebos for the Control Group
• A placebo is and inert substance given to the
control group that should have no effect on the
control group.
• The purpose of a placebo is to eliminate biases.
• Placebo effect- a phenomenon where people who
think they have been given a medication, even if it
is a placebo, can sometimes improve a health
condition just because they believe that the
medicine they receive will help them.
Guided Practice
• Turn to page 68 in your Mississippi SATP2
Review Guide and work questions 1-6.
Independent Practice:
Now work questions 1-6 on page 69. Write the
answers on the scantrons provided. Don’t
forget to write your names on your scantrons.
Turn in on my desk when you are done.