write down possible ways to solve the mystery…..how do i make a peanut butter and jelly sandwich?
TRANSCRIPT
Write down possible ways to solve the mystery…..how do I make a peanut butter and jelly sandwich?
TheScientifi
cMethod
Model, guide, or technique used to solve problems and to get information
Problem
Hypothesis
Experiment
Results
Conclusion
Repeat
Purple
Hippos
Eat
Really
Cold
Raviolis
6 STEPS Always in the form of a question
What you want to solve
1. State a Problem
ProblemUnder what color light will
plants grow best?
2. Form a Hypothesis
EDUCATED GUESSSuggested answer
to the problem
Based on prior knowledge
Hypothesis I think the plant under
green light will grow best because plants are green.
State one possible hypothesis for this experiment.
DO NOW: List the steps of the scientific method
3. Perform aExperiment
TEST IF HYPOTHESIS IS RIGHT OR
WRONGGather materialsDesign
procedures
Experiment
Grow the plants for 5 weeks. Each is placed under a certain color light. They will get the same amount of light, & will be watered every 2 days. Their height will be measured (in centimeters) once a week.
4. Record your
RESULTS
Writing down all data/observations that are made during the experiment
How? Graphs, charts…
2
4
6
8
10
12
Heig
ht
(cm
)
PLANTS
1 2 3 4 5 6
Observations Growth of
plants
5. State aConclusion
• Answers the question stated in the problem
• States if the hypothesis is right or wrong?
• Explains data
A conclusion is a multi-sentence statement that:
Conclusion My hypothesis was wrong. Plants grow
best under blue light, not green light. The plant under blue light grew 11cm while the plant under green light grew
only 2 cm.
6.Repeatthe experiment
The entire experiment must be done again to be valid.
Valid – proven to be logically true; to be proven legitimate
To find any errors
Final Summary
1. Name the steps of the scientific method.
2. Define the term hypothesis3. A possible explanation for an
observed set of facts is called a a.)variable b.) control c.) hypothesis d.) theory
A Controlled Experiment contains two groups:
Experimental Group
and the
Control Group
All experiments are designed to be controlled
the group that is used for
comparisonand does not
contain the independent
variable
2. Control group
the group of subjects that
are being tested on. This group
does receive the INDEPENDENT
VARIABLE
2. EXPERIMENTAL GROUP
Variable
Any factor(s) in an
experiment
There are 31.Independent 2.Dependent 3.Constant
The factor that is purposely altered by
the scientist, that may (or may not) lead to
change in the dependent variable.
Generally it is the factor that you are
testing.
1. Independent Variable
Independent variable = ?
SUNLIGHT
What is the variable is this experiment?
The color of the light
The factor that is being measured to
see if the independent
variable caused a change.
2. Dependent Variable
Dependent Variable?
Growth of plant
The variable or factor
that stays the same in both the Experimental
And the Control groups
-soil-pot -plant
3. Constant
Everything between the 2 groups must be exactly the
same except for the independent variable!!!
Identify 2 conditions, other than the size of the container and the amount of soil, that
should be held constant in this experiemtn.
1. ____________
2. ____________
What must be
done to make
results of anexperiment
more reliable
or valid?
•Repeat experiment•Use a larger subject/sample size
•Use only one variable
What is aTHEORY?
A hypothesis supported by many experiments
Thought to be true but can be changed
What is a LAW?
A statement that is believed to be true
What is the independent variable?Substance ZWhat is the dependent variable? height
Ex # 2: To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller.
Which setup is the control?Plant without Substance Z
Example #3How bright is right? An automobile manufacturer wants to know how bright brake lights should be in order to minimize the time required for the driver of a following car to realize that the car in front is stopping and to hit the brakes.
What is the independent variable?brightness of brake lightWhat is the dependent variable?time to hit brake
What is the independent variable?WaterWhat is the dependent variable?growth
Ex #4: A student placed 5 geranium plants of equal size in 5 environmental chambers. Growing conditions were the same for each plant except for the amount of water each received. At the end of 20 days, plant growth was measured.
5. An investigation was designed to determine the effect of ultraviolet light on mold spore growth. Two groups of mold spores were grown under identical conditions, except one group was exposed only to ultraviolet light, while the other group was grown in total darkness. In this investigation, the group of mold spores grown without receiving any ultraviolet light is known as the
a. experimental variableb. hypothesisc. controld. limiting factor
6. Which sentence represents a hypothesis?
a. Environmental conditions affect germination.
b. Boil 100 milliliters of water, let it cool, and then add 10 seeds to the water.
c. Is water depth in a lake related to available light in the water?
d. A lamp, two beakers, and elodea plants are selected for the investigation.
EX #1: Does beta-carotene protect against cancer? Beta-carotene supplements have been thought to protect against cancer. But one study suggests this is false. The study was conducted with 39,000 women aged 45 and up. These women were randomly assigned to receive a beta-carotene supplement or a placebo. Their health was studied over their lifetime. Cancer rates for women taking the beta-carotene supplement did not really differ from the cancer rates of those women taking the placebo.
What is the independent variable?supplements: beta-caroteneWhat is the dependent variable?How many patients got cancer
How do scientist create How do scientist create experiments?experiments?