The Scientific Method
Chapter 1 Section 2
Checks for Understanding
• 0807.Inq.1 Design and conduct an open-ended scientific investigation to answer a question that includes a control and appropriate variables.
• 0807.Inq.2 Identify tools and techniques needed to gather, organize, analyze, and interpret data collected from a moderately complex scientific investigation.
I can identify the steps used in the scientific method. I can establish a testable hypothesis.
I can explain how the scientific method is used to answer questions. I can explain how the scientific method is used to solve problems.
The scientific The scientific methodmethod
•A way to answer A way to answer questions and solve questions and solve problemsproblems
Step #1 Ask a Step #1 Ask a Question ?Question ?
•Scientist often ask Scientist often ask questions afterquestions after
making an making an
observationobservation
Using the scientific method requires that one be a good observer.
observation inferenceinvolves a logical
conclusion drawn from available evidence
and prior knowledge
uses the fivesenses to gather
information
Measurements
• Observations made with tools such as meter sticks, graduated cylinders, thermometers and stopwatches
• Observations should be accurately recorded so that scientists can use the information in future investigations
http://www.pa.uky.edu/sciworks/xtra/theq2.htm
http://www.bishopoconnell.org/pages/sitepage.cfm?page=4486
http://lightandshadows.net/20minutes.html
The Skeptical Chemist
Robert Boyle
Published “The Sceptical Chymist”
…stated that scientific speculationscientific speculation was worthless unless it was supportedby experimental evidenceexperimental evidence.
This principle led to the development of the scientific methodscientific method.
(in 1661)
“My mother the eye doctor”
Observation or Inference?
One player is holding a bat.The player holding the bat is talking.One of the teams is called the “Reds.”One player is wearing a catcher’s mask.One player is a catcher.Names are written on the uniforms.The players in the picture are on opposite teams.The adult is the umpire.The piece of paper is a note from the mother of the batter.The adult is holding a piece of paper.The mother of the batter is an optometrist or opthalmologist (an eye doctor).
Step #2 ResearchStep #2 Research the problem the problem
•Learn more about Learn more about
your subjectyour subject
•Scientist specialize in an Scientist specialize in an area and have learned a area and have learned a great deal of knowledge great deal of knowledge about itabout it
Step #3 Step #3 Form aForm a HypothesisHypothesis•Possible explanation Possible explanation
or answer to a or answer to a questionquestion
•Predicting what you Predicting what you think your think your experiment will experiment will showshow
The If-Then Format• Scientist usually state predictions in an
“If…, then…,because…., format
• Example:
If you compare hand brakes and coaster brakes on the same bicycles, then the hand brakes will be more effective at stopping the bikes quickly, because they apply pressure directly to the wheel hubs.
http://www.flickr.com/photos/mix_master_b/2983393331/
Step # 4 Design Step # 4 Design an experimentan experimentto test yourto test yourhypothesishypothesis•Find out if you are Find out if you are correctcorrect
A Scientific Experiment
procedure
the order of events
in an experiment;
the “recipe”
Experiments must be controlled; they
must have two set-ups that must differ
by only one variable.
The conclusion must be based on the data.
variable
any factor that
could influence
the result
A Controlled Experiment?
Step # 5 Record and Step # 5 Record and analyze your dataanalyze your data
DataPieces of information acquired through
experimentation
Observations are also called data.
There are two types of data.
qualitative data quantitative datadescriptions; measurements; no numbers must have numbers
Step # 6 Step # 6 State a State a conclusionconclusion•Was your Was your hypothesishypothesiscorrect?correct?
Drawing Conclusions
• Results support hypothesis
• Results do not support hypothesis
• More information is needed
Depending on your
conclusion, you might ask
a new question and gather
more information or
change the procedure
Step # 7 Step # 7 Communicate Communicate ResultsResults•Share your results Share your results
accurately and accurately and honestly with others honestly with others so they can so they can reproduce and verify reproduce and verify your datayour data
www.jefftolbert.com/ communicate.htm
The Metric System• Used by scientists all over the
world!
• Developed by France and known as the International System of Units (SI)
• Units are based on the number 10
• Help all scientists share and compare their observations and results
Prefix Symbol Meaning
kilo- k 1000
hecto h 100
deka- da 10
deci- d 0.1 or 1/10
centi- c 0.01 0r 1/100
milli- m 0.001 or 1/1000
Common SI Prefixes:
Measuring Length--the common SI measure of length is the meter (m). One meter = 39 inches (approx.)Common conversions include: 1 km = 1000 m, 1 m = 100 cm, 1 m = 1000 mm, and 1 cm = 10 mmScientists use a meter stick to measure length or distance.
modified by Liz LaRosa www.middleschoolscience.com 2009, from original posted at:www.science-class.net/PowerPoints/Observation_Inference_8th.ppt
Observation & Inference
Observations• Any information collected with the senses.
• Quantitative – measureable or countable» 3 meters long» 4 marbles» 50 kilograms» 35 degrees Celsius
• Qualitative – describable, not measureable » red flowers» smells like fresh baked cookies» Tastes bitter
• The skill of describing scientific events
Inference• Conclusions or deductions based on observations.• The process of drawing a conclusion from given evidence.
Practice: • Observations:
• I hear people screaming• I smell cotton candy, popcorn, and hamburgers• I see a lot of people
• Inference = ?
Look at these two sets of animal tracks.
List 3 OBSERVATIONS
Make an INFERENCE
Now what do you think?
Make 3 OBSERVATIONS
Make an INFERENCE
Now what do you think?
Make 3 OBSERVATIONS
Make an INFERENCE
Activity Page
www.middleschoolscience.com/footprints-isn.pdf
In your science notebook, write your conclusion.
Source of graphic:
http://bob.nap.edu/html/evolution98/evol6-e.html
Tools Used by Scientist
• To get the best measurements scientists need to use the proper tools
• Stopwatches, metersticks, balances, thermometers, spring scales and graduated cylinders are some of these tools
• Today you will learn how to properly measure volume
Scientific Tool For Today• Today you will learn
how to accurately measure volume
• Measured in liters (usually milliliters)
• Measured with a Graduated Cylinder
• Need to measure in the middle – at the meniscus Video