Name:
Date:
Pd:
Scientific Method -Experimental Design Guided Notes
Essential Question - How are scientific investigations designed and conducted?
A CONTROLLED EXPERIMENT is a test of the effect of a ________________ variable by changing it while keeping all other variables the
__________________
Controlled Experiment Vocabulary
The condition the
experimenter manipulates
Independent Variable (aka –
manipulated variable)
(changes
__________________)
_________________ Variable
(aka – responding variable)
The result measured by the
experimenter (it may or may
not change)
The conditions that are the
Constants (aka
________________ variable)
___________ in all trials
The trial used as a basis of
comparison
(usually found at either
Control Trial
__________ of the data
gathered)
Read the following description of an experiment and identify the
elements
Sam wished to investigate how fertilizer run-off affects the growth of
algae in freshwater lakes and streams. He set his experiment up this
way.
He placed 900 Ml of water into (5) 1,000 Ml glass beakers.
To each beaker he added 5 Ml of water from an aquarium which
contained a large concentration of algae.
The beakers were placed under a grow light which was timed to
provide 12 hours of light each day.
Liquid fertilizer was added to the beakers in the following amounts;
Beaker 1- no fertilizer
Beaker 2 - 2 ml of fertilizer
Beaker 3 - 4 ml of fertilizer
Beaker 4 - 6 ml of fertilizer
Beaker 5 - 8 ml of fertilizer
Each week a random sample from each of the beakers was examined
under a microscope to get a count of the number of algae cells
present
Independent Variable?
Dependent Variable?
Experimental Group?
____________________Group
The group/trials treated
differently from the control
group
Control Group?
Constants?
Name:
Date:
Read the following description of an experiment and identify the
elements
A study was created to test the effects of jazz on people’s sleep
patterns.
The hypothesis of the experiment was that if people listened to jazz
music as they fall asleep, they will sleep for longer periods of time
because the music would be soothing.
For the experiment, 2 groups of people were created.
Pd:
Read the following description of an experiment and identify the
elements
Suzie Q wants to know the effect of different colors of light on the
growth of plants.
She believes that plants can survive best in white light.
She buys 5 ferns of the same species, which are all approximately
the same age and height.
She places one each;
- in white light, in blue light, in green light, in red light, in the closet.
 One group was placed in a quiet room where they went to sleep
and they were timed on how long they slept.
All of the ferns are planted in Miracle-Grow and given 20 mL of
water once a day for 2 weeks.
 The other group was placed in a room where jazz music played
softly as they began to sleep and played throughout the night.
After the two weeks, Suzie observes the plants and makes
measurements.
As each group awoke, their sleep times were monitored.
Independent Variable?
Independent Variable?
Dependent Variable?
Experimental Group?
Dependent Variable?
Control Group?
Constants?
Experimental Group?
Write a hypothesis for this experiment.
Control Group?
List variables that should remain constant in this experiment?
What types of measurements can Suzie make on the plants to
determine how they did in different types of light
Name:
Date:
Read the following and identify the elements of the
experiment
Henry wanted to know if the amount of salt in water would affect
how quickly the salt would dissolve. He did some research about
the chemical components of salt and water. After doing his
research, Henry suggested a solution to the problem. He
believed the more salt that was added to the water the faster the
salt would dissolve. He set up the following experiment to see if
he was correct.
Using large glass beaker, Henry placed the following amount of
salt in 400ml of water.
Beaker A - 6 grams
Beaker B - 12 grams
Beaker C - 18 grams
Beaker D - 24 grams
Beaker E - 30 grams
Beaker F - 1 gram
Henry used the same stirring pace and stirred the water until no
more salt crystals could be seen in the beakers. Using his
stopwatch, he timed how long it took for the salt in each beaker
to dissolve. He repeated the entire procedure two more times.
Pd:
Read the following and identify the elements of the
experiment
SpongeBob loves to garden and wants to grow lots of pink
flowers for his pal Sandy.
He bought a special Flower Power fertilizer to see if will help
plants produce more flowers.
He plants two plants of the same size in separate containers with
the same amount of potting soil.
He places one plant in a sunny window and waters it every day
with fertilized water.
He places the other plant on a shelf in a closet and waters it with
plain water every other day.
1. What did SpongeBob do wrong in this experiment? Explain.
1. What was the problem Henry was trying to solve?
2. What was Henry's hypothesis?
3. What is the Independent Variable?
4. What is the Dependent Variable?
5. Which beaker represents Henry's control group? Why?
6. List 4 constants in this experiment.
2. What should SpongeBob do to test the effectiveness of Flower
Power fertilizer? Write an experiment.