FCAT ReviewFCAT ReviewThe Nature of ScienceThe Nature of Science

1) State a problem1) State a problem

• like asking a like asking a questionquestion

• ““Which Which fertilizer fertilizer works best works best to grow to grow beans?”beans?”

2) Research2) Research

• Use sources such Use sources such as books, as books, magazines, news magazines, news papers, journals, papers, journals, and experts to and experts to discover discover background background information about information about your problem.your problem.

3) Form a hypothesis3) Form a hypothesis

a) Use your research and a) Use your research and observations to predict observations to predict an answer to the an answer to the problemproblem

b) Is the purpose for the b) Is the purpose for the experiment, let’s other experiment, let’s other know what you are know what you are testingtesting

c) should be very specific c) should be very specific and based on researchand based on research

4) Conduct an experiment4) Conduct an experiment

ProcedureProcedure – Describes how – Describes how an experiment will be an experiment will be carried out – step by carried out – step by stepstep

This should test only one This should test only one hypothesishypothesis

Should only change one Should only change one variablevariable

Decide what equipment Decide what equipment and materials are neededand materials are needed

Take safety precautionsTake safety precautions

5) Analyze Data5) Analyze DataDataData – Recorded facts or – Recorded facts or

measurements from an measurements from an experimentexperiment

Describe the results in wordsDescribe the results in words

List the information in a table List the information in a table or graphor graph

Analyzing graphsAnalyzing graphs

6) Draw a conclusion6) Draw a conclusion

ConclusionConclusion – Logical answer to a problem – Logical answer to a problem question based on data question based on data

Think about what the data meanThink about what the data mean- Are there patterns?- Are there patterns?

Did the experiment test the hypothesis Did the experiment test the hypothesis correctly?correctly?- Do you need a new experiment?- Do you need a new experiment?

Do the data support the hypothesis?Do the data support the hypothesis?-Was the prediction right or wrong?-Was the prediction right or wrong?- Do you need a new hypothesis?- Do you need a new hypothesis?

ControlControl – A standard for comparison– A standard for comparison

A specimen or subject kept “normal” while A specimen or subject kept “normal” while the hypothesis is tested on othersthe hypothesis is tested on others– a control group has onlya control group has only

water – no fertilizerwater – no fertilizer– if all groups end up the if all groups end up the

same, does the same, does the

fertilizer really do fertilizer really do

anything? anything?

Probably not!Probably not!

Controlled VariableControlled Variable – Any factor that does – Any factor that does not change during an experimentnot change during an experiment

Same for all specimensSame for all specimens– where the plants are grown, soil, amount of where the plants are grown, soil, amount of

water, etc.water, etc.

IndependentIndependent – Changed by the experimenter – Changed by the experimenter– which plants get which fertilizer, X axiswhich plants get which fertilizer, X axis– the tested variablethe tested variable

DependentDependent – Changes as a result of the – Changes as a result of the independent variable, Y axisindependent variable, Y axis– bean production for each plantbean production for each plant– the outcome variablethe outcome variable

Importance of ModelsImportance of Models Benefits and limitations of Benefits and limitations of

modelsmodels Benefits- Benefits-

they can how us things that they can how us things that are too small or too big to be are too small or too big to be easily seeneasily seen

They show us complex They show us complex processesprocesses

They are safer/more stable They are safer/more stable to use than the real thingto use than the real thing

Limitations- Limitations- Not always to scaleNot always to scale Not the real thing so there Not the real thing so there

are some factors not are some factors not considered in models.considered in models.

VolumeVolume – – Amount of space occupied by Amount of space occupied by an objectan object

Length x Width x Height

Cubic meter – SI unit for volume (m3)

Measure water displacement in a graduated cylinder

MassMass – – Amount of matter in an objectAmount of matter in an objectKilogram – SI unit for

mass– Gram, milligram

– One liter (L) of pure water has mass of 1 kg

WeightWeight – – The measure of the force of The measure of the force of gravity acting on an objectgravity acting on an object

Newton (N) – SI unit for force and weight

Weight changes as gravity changes

DensityDensity – – Amount of mass an object has for Amount of mass an object has for its volumeits volume

Density =           

Mass= Density x Volume

Volume= Mass/ Density

You need to know how to

change around the standard

equation!!!!

Mass/Volume

Object Mass Volume Density

A 15 3 ?

B ? 4 3

C 20 ? 4

D ? 5 5

E 21 3 ?

F 18 ? 3

WHY IS IT IMPORTANT THAT SCIENTIFIC WHY IS IT IMPORTANT THAT SCIENTIFIC INVESTIGATIONS ARE REPLICABLE?INVESTIGATIONS ARE REPLICABLE?

- So that they other scientists can repeat the experiment to - So that they other scientists can repeat the experiment to verify the results. verify the results.

WHAT IS THE DIFFERENCE BETWEEN REPLICATION AND WHAT IS THE DIFFERENCE BETWEEN REPLICATION AND REPETITION(Repeated trial)?REPETITION(Repeated trial)?

- Replication is when the whole experiment is repeated by - Replication is when the whole experiment is repeated by someone else. Repetition(repeated trial) is when you someone else. Repetition(repeated trial) is when you repeat one part or a couple parts to get more accurate repeat one part or a couple parts to get more accurate results. results.

Checking Validity

WHAT IS THE DIFFERENCE?WHAT IS THE DIFFERENCE?

SCIENTIFIC THEORYSCIENTIFIC THEORY: A WELL-TESTED EXPLANATION : A WELL-TESTED EXPLANATION FOR A WIDE RANGE OF EXPERIMENTS AND FOR A WIDE RANGE OF EXPERIMENTS AND OBSERVATIONS.OBSERVATIONS.

(plate tectonics, evolution, cell theory, atom theory)(plate tectonics, evolution, cell theory, atom theory)

SCIENTIFIC LAWSCIENTIFIC LAW: A STATEMENT THAT DESCRIBES WHAT : A STATEMENT THAT DESCRIBES WHAT SCIENTISTS EXPECT TO HAPPEN EVERY TIME UNDER A SCIENTISTS EXPECT TO HAPPEN EVERY TIME UNDER A PARTICULAR SET OF CONDITIONSPARTICULAR SET OF CONDITIONS

(gravity, superposition, conservation of mass, conservation (gravity, superposition, conservation of mass, conservation of energy)of energy)

Scientific theory vs. Scientific law

*EVIDENCE IS DATADATA AND OBSERVATIONS THAT HAVE BEEN COLLECTED THROUGH SCIENTIFIC PROCESSES AND THAT ALSO EXPLAIN A PARTICULAR OBSERVATION.

*ALL SCIENTIFIC INVESTIGATION INVOLVE THE COLLECTION OF RELEVANT EVIDENCE TO SUPPORT RESEARCHER’S CONCLUSIONS.

*SCIENTIFIC EXPLANATIONS ARE BASED ON EVIDENCE, LOGICAL REASONING, PREDICTIONS, AND MODELING.

Science is always changing!

New evidence can be discovered to contradict previous theories and ideas

Sample QuestionSample Question

In scientific research, scientists should clearly In scientific research, scientists should clearly publish the procedures used in their publish the procedures used in their experiments, along with their observations and experiments, along with their observations and data. Whys is it important for someone else to data. Whys is it important for someone else to know the procedure?know the procedure?

A.A.Knowing the procedure allows for replication Knowing the procedure allows for replication of the experimentof the experimentB.B.Knowing the procedure helps others Knowing the procedure helps others understand the reasons for the experiment.understand the reasons for the experiment.C.C.Knowing the procedure demonstrates the Knowing the procedure demonstrates the technical proficiency of the scientist.technical proficiency of the scientist.D.D.Knowing the procedure can explain how the Knowing the procedure can explain how the data were interpreted by the scientist.data were interpreted by the scientist.

The following statements were taken from the procedures of four different investigations.

The statement from which investigation is an example of The statement from which investigation is an example of repetition(repeated trial)? repetition(repeated trial)? A. Investigation 1 A. Investigation 1 B. Investigation 2 B. Investigation 2 C. Investigation 3 C. Investigation 3 D. Investigation 4 D. Investigation 4

Sample Question

Until the 1500’s doctors thought diseases were Until the 1500’s doctors thought diseases were caused spontaneously. Scientists began proposing that caused spontaneously. Scientists began proposing that diseases were caused by seedlike entities that could be diseases were caused by seedlike entities that could be passed among people. After the invention of the passed among people. After the invention of the microscope, doctors came to know that many diseases microscope, doctors came to know that many diseases were actually caused by microscopic living organisms, were actually caused by microscopic living organisms, like bacteria. What does this suggest about the nature like bacteria. What does this suggest about the nature of scientific knowledge?of scientific knowledge?

A. Scientific knowledge should not be considered valid A. Scientific knowledge should not be considered valid because it changes over time.because it changes over time.

B. Technology has improved enough that scientific B. Technology has improved enough that scientific knowledge can stop changing.knowledge can stop changing.

C. New discoveries and evidence are more important C. New discoveries and evidence are more important than repeatable results.than repeatable results.

D. Scientific knowledge changes over time based on D. Scientific knowledge changes over time based on evidence. evidence.

Sample Question

Scientists create both scientific theories and scientific laws Scientists create both scientific theories and scientific laws as they make observations and conduct experiments about as they make observations and conduct experiments about the natural world. Which of the following statements most the natural world. Which of the following statements most accurately compares the difference between scientific accurately compares the difference between scientific theories and scientific laws?theories and scientific laws?

A. Scientific laws are based on evidence, while scientific A. Scientific laws are based on evidence, while scientific theories are not.theories are not.B. Scientific theories involve only biology, while laws B. Scientific theories involve only biology, while laws involve all types of science.involve all types of science.C. Scientific theories involve mathematical equations, while C. Scientific theories involve mathematical equations, while scientific laws are based on observations.scientific laws are based on observations.D. Scientific theories are ideas that explain natural events, D. Scientific theories are ideas that explain natural events, while scientific laws more reliably predict natural events.while scientific laws more reliably predict natural events.