Scientific Inquiry and the Scientific Method The Way Cool Way Science is Done

Scientific Inquiry and the

Scientific

Method

The Way CoolWay

Science is Done

What is

Science?Science is a

process of inquiry.

It's a way of

knowing.

That’s great,

but HOW ?!

What is

Science?

“A Process of Inquiry”Process = a series of logical steps

Inquiry = an examination into facts or principles; a systematic

investigation

How is this done?

Thinking like a scientistObserving – becoming aware of something by using our senses

Let's say you have been hired by a local dentist to do a study on local candy eating habits in the neighborhoods around his office. You can go about gathering data in one of two ways, through direct observation, or indirect observation.

Direct observations – you are looking at an actual behavior or occurrence of some event.

Example – you observe customers in a store and count how many bags of candy they purchase.

Indirect observations – you observe the results of a certain behavior or occurrence of an event.

Example – you look through trash cans on garbage day to see how

many empty candy bags are in each trash bin.

Thinking like a scientistQualitative observations – these are descriptions of

what we observe. For example, it is hot outside today.(think of the stem for “qualitative” - “quality”)

Quantitative Observations - these are measurements of what we observed.

For example, it is 90 degrees Fahrenheit outside today.(think of the stem for “quantitative” - “quantity”)

Quantitative observations or measurements should be as precise and accurate as possible.

Precision = how exact the measurement is.

Accuracy = how correct a measurement is.

Thinking like a scientistInference – an explanation of an observation, a conclusion based on evidence or premises

Remember the ice cube experiment from our scientific method video?

The girl inferred that because the Styrofoam felt warmer, it would melt the ice faster than the wood or aluminum.

Was her inference correct?

An inference is a logical conclusion based on facts and prior knowledge, but it is not necessarily factual!

Ice melting faster on aluminum pan = an anomaly

The inference led the girl in the video to think one way, but her experiment produced a very different outcome.

Result? More questions.

The Scientific

Method

Ask QuestionIt all begins with a question

about something you observe.

“How…?”“What…?”

“When…?”“Who…?”

“Which…?”“Why…?”

“Where…?”

In order for the scientific method to answer your question, it must be about something you can measure, preferably with a number.

The Scientific Method

Do backgroundresearch

Don’t reinvent the wheel.

Research your topic to find out

what others have already done.

Research will help you avoid mistakes of

the past, and may help you refine your

original question and hypothesis, as well

as helping you structure your experiment

for the best possible results.


ConstructHypothesis

“If I do this (cause), then this will happen (effect).

Your hypothesis should be measurable, and it should

help you answer your original question.

This is where you state what

you think will happen. Your

hypothesis should be an “if…

then…” statement

(“cause and effect” )


Your experiment will determine

whether your hypothesis is true

or false. It should be a fair test.

You make it fair by changing

only one variable at a time.


Test with an Experiment

You should also repeat your

experiments several times to

make sure that the first results

you got were not due to

chance.

Claims & Evidence

Draw Conclusions


After experiment is complete, compile your data and analyze it to see if you can support your claims with evidence.

Hypothesis was correct

Hypothesis was incorrect

Go to next step

Determine why, revise hypothesis or revise experiment, repeat experiment

Report Results

The Scientific MethodOnce your work is complete, write up your experiment in the proper format.

In our case, that will be a lab report.

We will discuss how to write the lab report later.

Experimental DesignVariables – the nuts and bolts of your experiment

Remember your hypothesis? It said

“If I do this, then that will happen.”

The “this” is a variable that you will change.

The “that” is a variable that changes due to the change of “this.”

Confused?

Let’s give them more proper names – independent, dependent, and control variables – and take a look at each one.

Experimental DesignVariables 101

Independent variables - When you design your experiment, you will want to change only one variable, and then observe what happens. The variable you change is the “independent” or “manipulated” variable.

Dependent variable – When you change the independent variable, you will observe how the dependent variable changes. We also call the dependent variable the “responding variable,” since it changes in response to the change you make to the independent variable.

Experimental DesignVariables 101

Controlled variables – All other variables in an experiment

must stay the same. These are the controlled variables, and

you will want to watch them as close as the dependent

variable. If for some reason one of your controlled variables

changes during an experiment, you will not be able to say that

the results you got were not due to the change in the control

variable or the change in the independent variable.

Finally, all your variables should be measurable.

Let’s look at some examples….

QuestionIndependent Variable

(What I change)Dependent Variables

(What I observe)

Controlled Variables (What I keep the

same)

* The Faucet * Water pressure, or how much the water is "pushing"

"Different water pressure might also cause different amounts of water to flow and different faucets may behave differently, so to insure a fair test I want to keep the water pressure and the faucet the same for each faucet opening that I test."

* Stirring * Type of sugar

"More stirring might also increase the amount of sugar that dissolves and different sugars might dissolve in different amounts, so to insure a fair test I want to keep these variables the same for each cup of water."

Amount of water flowing measured in liters per minute

Water faucet opening (closed, half open, fully open)

How much water flows through a faucet at different openings?

Does heating a cup of water allow it to dissolve more sugar?

Temperature of the water measured in degrees Centigrade

Amount of sugar that dissolves completely measured in grams

QuestionIndependent Variable

(What I change)Dependent Variables

(What I observe)

Controlled Variables (What I keep the

same)

* The Faucet * Water pressure, or how much the water is "pushing"

"Different water pressure might also cause different amounts of water to flow and different faucets may behave differently, so to insure a fair test I want to keep the water pressure and the faucet the same for each faucet opening that I test."

* Stirring * Type of sugar

"More stirring might also increase the amount of sugar that dissolves and different sugars might dissolve in different amounts, so to insure a fair test I want to keep these variables the same for each cup of water."

Amount of water flowing measured in liters per minute

Water faucet opening (closed, half open, fully open)

How much water flows through a faucet at different openings?

Does heating a cup of water allow it to dissolve more sugar?

Temperature of the water measured in degrees Centigrade

Amount of sugar that dissolves completely measured in grams

QuestionWhich AA battery maintains its voltage for the longest period of time in low, medium, and high current drain devices?

HypothesisHypothesis: As I test for increasingly longer periods of time, the Energizer AA battery will maintain a higher voltage than other batteries.

VariablesIndependent Variable - Time, how long each battery operatesDependent Variable - Voltage

Experimental Group Controlled Variables for Each Group

Low current drain Same portable CD playerPlay the same music trackPlay at the same volume level

Medium current drain Identical flashlightIdentical light bulb

High current drain Same camera flash

All groups Battery size (AA)Constant temperature (A battery works better at a warm temperature.)

Variables Checklist

What Makes for Good Variables?

Is the independent variable measurable?

Can you change the independent variable during the experiment?

Have you identified all relevant dependent variables, and are they all caused by and dependent on the independent variable?

Are all dependent variable(s) measurable?

Have you identified all relevant controlled variables?

Can all controlled variables be held at a steady value during the experiment?

Yes / No

Yes / No

Yes / No

Yes / No

Yes / No

Yes / No

If you have good

Variables, you should be able to

answer "Yes" to

every question

below

Patty Power

Mr. Krabs wants to make Bikini Bottoms a nicer place to live. He has created a new

sauce that he thinks will reduce the production of body gas associated with eating

crabby patties from the Krusty Krab. He recruits 100 customers with a history of gas

problems. He has 50 of them (Group A) eat crabby patties with the new sauce. The

other 50 (Group B) eat crabby patties with sauce that looks just like new sauce but

is really just mixture of mayonnaise and food coloring. Both groups were told that

they were getting the sauce that would reduce gas production. Two hours after

eating the crabby patties, 30 customers in group A reported having fewer gas

problems and 8 customers in group B reported having fewer gas problems.

Which people are in the control group?

What is the independent variable?

What is the dependent variable?

What should Mr. Krabs’ conclusion be?

Why do you think 8 people in group B reported feeling better?

Slimotosis

Sponge Bob notices that his pal Gary is suffering from slimotosis, which occurs

when the shell develops a nasty slime and gives off a horrible odor. His friend

Patrick tells him that rubbing seaweed on the shell is the perfect cure, while Sandy

says that drinking Dr. Kelp will be a better cure. Sponge Bob decides to test this

cure by rubbing Gary with seaweed for 1 week and having him drink Dr. Kelp.

After a week of treatment, the slime is gone and Gary’s shell smells better.

What was the initial observation?



What should Sponge Bob’s conclusion be?

Patty Power

Which people are in the control group?

Group B


New sauce


Amount of gas

What should Mr. Krabs’ conclusion be?

The new sauce appears to work as it reduced the amount of gas

produced in 60% of the people tested.

Why do you think 10 people in group B reported feeling better?

They thought they were getting the new sauce as a result thought that

they didn’t have as much gas. (Placebo effect)

Slimotosis

What was the initial observation?

Slimotosis on Gary’s shell


Cures (Seaweed and Dr. Kelp)


Slime and odor

What should Sponge Bob’s conclusion be?

Although Gary’s symptoms have disappeared, it is not known which cure

was the one that worked. He should redo the experiment and include a

control group as well as two other testing groups for each of the proposed

cures.

Documents

Scientific Inquiry and the Scientific Method The Way Cool Way Science is Done