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