Transcript The Scientific Method

The Scientific Method
Scientific Process
 Problem or Question
 Gather information
 Hypothesis (prediction)
 Experimentation
 Conclusions
Observations and Questions
 Science is ultimately
based on observation
 Observations often lead
to questions ---> which
lead to experiments to
answer the questions
 People jump back
when they see a large
dog.
 Why are people afraid
of large dogs.
 People are afraid of
large dogs because TV
and the Media often
portray large dogs as
vicious and mean.
Hypothesis
 a testable statement, can be shown to be true or
false by experimenting or observation
Good
Bad
1. Plants will grow taller when given
Miracle Grow
1. Plants will grow better when given
Miracle Grow.
2.Girls will score higher on math tests
than boys
2. Girls are smarter than boys.
3. Hermit crabs choose colorful shells
over drab shells.
3. Hermit crabs like colorful shells
Experiment
 Experimentation - a planned procedure
designed to test the hypothesis.
 Experimental Group -receives some kind of
treatment or condition
 Control Group - receives no treatment, used to
compare
Example of an experimental design
 Hypothesis: Plants will grow
taller when given Miracle
Grow.
 Plants A & B are both given
the same amount of light,
water, and are stored at the
same temperature. Plant A is
given Miracle Grow.
 All the variables are kept
constant except the one you are
testing.
Variables
 Independent Variable - the factor you change,
what you do to your exp. group. (Miracle Grow)
 Dependent Variable - what happens as a result of
that treatment, what you are measuring (height of
plant)
Practice
 In an experiment, a goldfish is placed in a 15 gallon
tank. Another goldfish is placed in a 50 gallon
tank. The experimenter feeds them exactly the same
amount of food and weighs them one year later to
see which one grew the most.

 What is the independent variable in this experiment?
 What is the dependent variable?
Collecting Data
 Data should always be presented in a neat fashion, usually
tables or graphs
Conclusions
 Based on the data, a scientist then determines
whether the hypothesis was supported or refuted.
Science is subject to change when new evidence is
found. While experimentation and observations can
provide strong evidence for a conclusion, it is not
absolute proof
Taking it one step further
 Theory- well tested explanation that unifies a set of
observations

Theory of Evolution
How are a Theory and a Hypothesis different?????
Homework: Pick a Question and Design an
Experiment
 1. Will human urine repel sharks?
 2. Does the color red make lizards more aggressive?
 3. Will fish grow larger if placed in a larger tank?
 4. Does exercise reduce your risk of heart attack?
 5. Does aspirin keep cut flowers fresh longer?
How to Display Data
WHEN TO USE GRAPHS AND HOW TO
CHOOSE THE RIGHT TYPE OF GRAPH
Examples of Graphs
Line graph
Bar Graph
Examples of Graphs
Pie charts
Line Graph
A line graph is
most useful in
displaying data or
information that
changes
continuously over
time.
Date
Temperature
1
10
2
25
3
30
4
42
5
23
6
25
7
40
Bar Graph
Bar graphs are an
excellent way to
show results that
are one time, that
aren't continuous especially
samplings such as
surveys,
inventories, etc.
Activity
Number
Visit W/Friends
175
Talk on Phone
168
Play Sports
120
Earn Money
120
Use Computers
65
 Circle or pie graphs are particularly
Pie Charts
good illustrations when considering
how many parts of a whole are
inception.
Graph Quiz Tommorow
YOU WILL HAVE A QUIZ ON GRAPHING
TOMORROW !
DON’T WORRY WE ARE GOING TO PRACTICE
YOUR GRAPHING SKILLS.