The The Scientific Scientific MethodMethod

By Miranda SimmonsBy Miranda SimmonsFall 2010Fall 2010

Essential Question:Essential Question:

How do scientists pose and How do scientists pose and answer questions about answer questions about

nature?nature?

The Scientific MethodThe Scientific Method

The scientific methodscientific method is a procedure that

scientists use to solve a problem. It is a process of inquiry that involvesobservations, questions, hypotheses,predictions and test of predictions.

1. Identify the problem.1. Identify the problem.

Make an observationobservation—information gathered using the senses.

Then ask a question, that is, identify the problemidentify the problem

2. Research the problem.2. Research the problem.

Do some background research to see what you can find out about the problem in question.

3. Form a hypothesis.3. Form a hypothesis.

Now that you have done a little research, you can form an ““educated” guesseducated” guess as to what you think the solution to the problem is.

Must write in “if… then… statementif… then… statement” (cause and effect)

If…

…then

4. Test the hypothesis.4. Test the hypothesis.

There can only be There can only be oneone variable variable to test.to test.

Design and perform an experimentexperiment to test the hypothesis.

Not like this though.

5. Collect, record, and 5. Collect, record, and analyze data.analyze data.

6. Draw a conclusion.6. Draw a conclusion.

If your conclusion does not support your hypothesis, then, you must start overstart over and come up with a new hypothesisnew hypothesis.

If the conclusion does not support thehypothesis, the scientist forms anotherforms anotherhypothesis and tests it again.hypothesis and tests it again. 

If the conclusion supports the hypothesis,the experiment should be repeatedrepeated manytimes.

The hypothesis may then become a theorytheory or a scientific law.scientific law.

Here is an Example!Here is an Example!

The scientific process is NOT just used by scientists.

You use it most everyday whether you realize it or not!

1. Identify the Problem.1. Identify the Problem.

Don’t cry!Don’t cry!

Use the scientific methodUse the scientific methodto figure out why!to figure out why!

Why won’t my car start?Why won’t my car start?

2. Do some background research.2. Do some background research.

3. Form a hypothesis3. Form a hypothesis

IfIf my car doesn’t start, thenthen it must have a deadbattery.

4. Now test your hypothesis 4. Now test your hypothesis with an experiment.with an experiment.

What is an EASY EASYEASY EASY test (experiment) that you can perform to see if the battery is dead?

Check to see ifthe lights come on!

OROR

Check to see if theradio comes on!

5. Collect, Record and Analyze the Data.5. Collect, Record and Analyze the Data.

In this case, it is as simple as making a mental notemental notethat the lights did or did not come on!

Hmmm, the Hmmm, the lights did lights did come on!come on!

6. Draw a Conclusion.6. Draw a Conclusion.The car’s battery is not the reason why my carwon’t start.

In this case, the conclusion does not support thehypothesis.

So now what???So now what???

If the conclusion does not support the hypothesis, then you still have the problem.

You must form a new hypothesis!You must form a new hypothesis!

Form a New Hypothesis.Form a New Hypothesis.

IfIf my car won’t start, thenthen it must be out of gas.

Now test your hypothesis with an experimentNow test your hypothesis with an experiment..

What is an EASY EASYEASY EASY test (experiment) that you can perform to see if the car is out of gas?

Check the gas gauge!

OROR

Add gas!

Collect, Record and Analyze the Data.Collect, Record and Analyze the Data.

In this case, it is as simple as making a mental notemental notethat the car does or does not crank after gas hasbeen added!

Hmmm, the Hmmm, the car will car will

crank now!crank now!

Draw a Conclusion.Draw a Conclusion.The car would not start because it was out of gas.

In this case, the conclusion does In this case, the conclusion does support the hypothesis.support the hypothesis.

Problem is solved!Problem is solved!

Think! Think! Can you can name all six steps?Can you can name all six steps?

Steps of the Scientific MethodSteps of the Scientific Method

1. _______ ___ ______

2. _________the problem

3. Form a _________

4. _____ the hypothesis (with a what?) 5. Collect, record and ________ data.

6. _____ __ _________

Hey, did you get all that?Hey, did you get all that?

IdentifyIdentify thethe problemproblem

ResearchResearch

hypothesishypothesis

TestTest

analyzeanalyze

DrawDraw aa conclusionconclusion

Okay, do it again!Okay, do it again!

Step 1Step 1 Step 2Step 2

Step 4Step 4

Step 3Step 3

Step 5Step 5Step 6Step 6

How did you do?How did you do?

Identify ProblemIdentify Problem

How did you do?How did you do?

Identify ProblemIdentify ProblemResearch ProblemResearch Problem

How did you do?How did you do?

Identify ProblemIdentify ProblemResearch ProblemResearch Problem

Form hypothesisForm hypothesis

How did you do?How did you do?

Identify ProblemIdentify ProblemResearch ProblemResearch Problem

Test hypothesisTest hypothesis

Form hypothesisForm hypothesis

How did you do?How did you do?

Identify ProblemIdentify ProblemResearch ProblemResearch Problem

Test hypothesisTest hypothesis

Form hypothesisForm hypothesis

Collect, record,Collect, record, analyze dataanalyze data

How did you do?How did you do?

Identify ProblemIdentify ProblemResearch ProblemResearch Problem

Test hypothesisTest hypothesis

Form hypothesisForm hypothesis

Collect, record,Collect, record, analyze dataanalyze data

Draw conclusionDraw conclusion

Steps of the Scientific MethodSteps of the Scientific Method1. Identify the problem

2. Research the problem

3. Form a hypothesis

4. Test the hypothesis 5. Collect, record and analyze data

6. Draw a conclusion

Parts of an ExperimentParts of an Experiment

Parts of an Experiment – The Parts of an Experiment – The VariablesVariables

There are 3 types of variables3 types of variables  manipulativemanipulative – variable that you control (the cause); a.k.a. independentindependent variable

respondingresponding – variable that changes as a result of what you changed or manipulated inthe experiment (the result); a.k.a. dependentdependentvariable controlcontrol –(a.k.a. constantsconstants) are variables orfactors that remain unchanged throughoutthe experiment

Problem: Do plants require sunlight in Problem: Do plants require sunlight in order to live?order to live?

Place one plant in darkness.

Experiment: ProcedureExperiment: Procedure

Place one plant in sun light.

What is the What is the manipulativemanipulative variable for variable for this experiment?this experiment?

LIGHT!LIGHT!

What is the What is the responding responding variable?variable?

Its whether the plant lives or dies.

It’s the life of the plant.It’s the life of the plant.

What are some control variables?What are some control variables?

Same kind of plant.

Same kind and amount of fertilizer.

Same amount of water.

Same temperature.

Other Control VariablesOther Control Variables

Same size plants.

Same type soil.

Same starting healthy condition.

Can you name even moreCan you name even more control variables? control variables?

Same watering and feeding time each day.

Same size pot.

Same amount of soil.

The EndThe End

Another ExampleAnother ExampleProblem: Problem: Do students perform better on test whileDo students perform better on test whilelistening to music?listening to music?

The other group of students

do not get music played while

taking their test.

Experiment: ProcedureExperiment: Procedure

One group of students gets

the music.

What is the What is the manipulativemanipulative variable for variable for this experiment?this experiment?

What is the What is the responding responding variable?variable?

The test grades.The test grades.

What are some control variables?What are some control variables?

Same type of room temperature

& environment.

Same amount of time to take test.

Same test.

Parts of an Experiment – The Parts of an Experiment – The GroupsGroups

The control groupThe control group – used for comparison to show

that that the result of an experiment is really due to the condition being tested. This group does NOT receive the testThis group does NOT receive the test..

The experimental groupThe experimental group – group that will receive the test (the manipulative variable).

The dataThe data – info. gathered from observations

during an experiment.

Two types:

1. qualitativequalitative- collected through the senses ex. color, texture, general properties

2. quantitativequantitative involves numbersnumbers (quantity) or measurements - ex. how much?

Parts of an Experiment – The DataParts of an Experiment – The Data

• Qualitative data are descriptions in words of what is being observed.

• It is based on some quality of an observation, such as sight, sound, color, odor, or texture.

Qualitative data Qualitative data - collected through the senses ex. color, texture, general properties.

Qualitative DataQualitative Data

The data is objective—they are the same no matterwho measures them.

It includes measurements such as mass, volume,temperature, distance, concentration, time or frequency.

QuantitativeQuantitative involves numbersnumbers (quantity) or measurements - ex. how much?

Quantitative DataQuantitative Data

Quantitative data are numeric measurements.

Suppose that a marine biologistobserves the behavior andactivities of dolphins.

She identifies different dolphinswithin the group and observes them every day for a month.

She records detailedobservationsabout their behaviors.

Some of her observations arequalitative data and some arequantitative data.

Qualitative data examplesQualitative data examples

Dolphin colors rangefrom gray to white.

Dolphins in a podengage in play behavior.

Dolphins have smoothskin.

Quantitative data examplesQuantitative data examplesThere are ten dolphins inthis pod.

Dolphins eat an equivalentof 4-5% of their bodymass each day.

The sonar frequency mostoften used by thedolphins is around100kHz.

Identify Data TypesIdentify Data TypesSuppose that you are a biologist studying jackals in their naturalhabitat in Africa.

You observe their behaviors and interactions, and take picturesof their interactions to study later.

Examine the photo & give:

*3 examples of qualitative data

*3 examples of quantitative data

Identify Data TypesIdentify Data TypesSuppose a team of scientists is studying the migration of animal species in Africa.One of the scientists takes this photograph.

Examine the photo & give:

*3 examples of qualitative data that could be collected during this research

*3 examples of quantitative data that could be collected during this research

Theory Theory – well tested explanationexplanation ofhow something in nature works; it is

well supported.

Ex. theory of the disappearance of the dinosaursdisappearance of the dinosaurs

Scientific LawScientific Law – A rule of nature that states a fact, but does not attempt to explain it.

Ex. Newton’s 3 laws of motionNewton’s 3 laws of motion

Theory v.s. LawTheory v.s. Law

Science and Science and TechnologyTechnology

*Science does not address things that cannot be tested, such as beauty or ethics.

 *Science deals only with hypotheses that are

testable and subject to modification as knowledge and methods of testing advance.

* Hypotheses that are not testable, such as those involving supernatural causes, lie outside the realm of science.

Also, unapproachable by science are questions such as,

What is the spiritual meaning of life?

* The quest for answers to questions like this lie in the realms of philosophy and religion.

Biology, technology and society are Biology, technology and society are connected in important waysconnected in important ways

Technological advances stem from scientificresearch, and research benefits from

technology.

The goal of science is to understand naturalphenomena.

The goal of technology is to apply scientificknowledge for some specific purpose. Scientists often speak of discoveries.

Engineers often speak of inventions.

The beneficiaries of those inventions also include scientists, who use new technology in their research.

And scientific discoveries often lead to thedevelopment of new technologies.

Science is driven by curiosity, whereas technology is driven by the needs and wants of people and on the social environment at times.

Technology has improved our standard of living in

ways, but not without having adverse consequences.

Technology that keeps people healthier has enabled Earth’s population to grow more than tenfold in the past three centuries, to more than 6 billion.

The environmental effects of thisThe environmental effects of thispopulation growth can be population growth can be

devastating:devastating:•Global warming

•Toxic wastes

•Acid rain

•Deforestation

•Nuclear accidents

•Extinction of species

Science can help us identify such problems and provide insight into what course of action may prevent further damage.

 But solutions to these problems have asmuch to do with politics, economics, andcultural values as with science andtechnology.

Now that science and technology havebecome powerful aspects of society,

every citizen has a responsibility to develop a reasonable amount of scientific literacy.

 The science-technology-society

relationship is an important aspect of a biology course.

Why study biology?Why study biology?

Your knowledge of biology can help you makeinformed decisions about issues involvingendangered species, biotechnology, medicalresearch, and pollution control, to name a few.

Connections to Everyday LifeConnections to Everyday Life::

 o birth and death

o human population

o nutrition, exercise and dieting

o medical concerns of all kinds

o agriculture, including forestry

o biodiversity and endangered species

o pollution and environmental changes due to global warming.

Biology is connected to our lives in many ways:

Biology and Your HealthBiology and Your Health

An understanding of biology on many different levels—genetic,chemical, and cellular, for example—can help you make any numberof lifestyle choices that affect your health.

Why is it important to where sunscreen?What are the benefits of exercise?What are the effects of using alcohol, illegal drugs, and tobacco?

Cigarette smoke does not just affect the lungs; it can also change aperson’s body chemistry.

Lower levels of monoamine oxidase in the brain can affect mood andlower levels in the liver could contribute to high blood pressure.

Biologists and other scientists research environmental issues such aspollution, biodiversity, habitat preservation, land conservation, andnatural resource use, but decisions about the future are not in thehands of scientists.

It is up to everyone to make decisions based on evidence andconclusions from many different sources.

Many technological advances stem fromthe scientific study of life.

Evaluating everyday reports in the popularpress about a large range of subjectsrequires critical thinking and somefamiliarity with many areas of biology.

Some News Issues Related to Some News Issues Related to BiologyBiology

Global warming

Air and water pollution

Endangered species

Genetic engineering

Test tube babies

Nutrition

Aerobic exercise

Weight control

Medical advances

AIDS and the immune system

Evolution is connected to our Evolution is connected to our everyday liveseveryday lives

Evolution is the core theme of biology.

Evolution tells us that all living species aredescendants of ancestral species that havebecome modified as natural selectionadapts populations to their environments.

As environments change, populations change.

Biologists now recognize that differences in DNA among individuals, populations, and species reflect the pattern of evolutionary change.

Evolution teaches us that the environment mattersbecause it is a powerful selective force for traitsthat best adapt populations to their environment.

Evolution affects everyday life in medicine, agriculture, forensics, and conservation.

Environmental changes are powerful selective pressures on the adaptive traits of many populations.

The EndThe End

Did ya? Huh? Did ya???Did ya? Huh? Did ya???

1. Identify the problemIdentify the problem

2. ResearchResearch the problem

3. Form a hypothesishypothesis

4. TestTest the hypothesis (with an experimentexperiment)

5. Collect, record and analyze dataanalyze data

6. Draw a conclusionDraw a conclusion