Transcript InquiryNotes_2015x

Scientific Inquiry
and the
Scientific
Method
The Way Cool
Way
Science is Done
What is Science?
Science is a
process of inquiry.
It's a way of knowing.
It is a human endeavor to
understand and describe
the world we live in.
That’s great,
but HOW ?!
“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 scientist
Observing
Using your senses (see, hear, smell,
touch, taste?) to gather information.
Must be factual and accurate.
Written and/or drawn observations
are best.
You can go about gathering data in one of two
ways, through direct observation, or indirect
observation.
Thinking like a scientist
Direct vs. Indirect Observations
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.
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 scientist
Qualitative 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 scientist
Inference – a logical explanation of an
observation; a conclusion based on evidence
and/or previous knowledge.
An anomaly is something that deviates from
what is standard, normal, or expected.
Think you can?
Imagine you are
walking through the
desert and you come
upon these tracks on
the ground.
What can you infer?
Imagine you are walking through the desert and you
come upon these tracks.
Now what can you infer?
Now how does your
inference change?
The Scientific
Method
The Scientific Method
It all begins with a question. It could be a question about
something you observe, or it might be
something you are curious about.
Ask Question
“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
Don’t reinvent the wheel.
Research your topic to find out
Do background
research
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.
The Scientific Method
This is where you state what
you think will happen. Your
Construct
Hypothesis
hypothesis should be an
“if…then…” statement
(“cause and effect” )
“If I do this (cause), then this will happen (effect).
Your hypothesis should be measurable, and it should
help you answer your original question.
The Scientific Method
Hypothesis vs. Predictions vs. Inferences
Hypotheses and predictions are similar in that they are trying to guess the outcome
of a future event. Both are based on observations and prior knowledge.
An hypothesis is an “If……, then…….” statement,
whereas a prediction is an “I think….” statement.
Hypotheses and predictions differ from inferences in one major way.
Can you think what that might be?
It’s all about timing. A prediction or hypothesis is a
statement about something that hasn’t happened yet,
whereas an inference is typically an explanation about
an event that event that has already occurred.
The Scientific Method
Your experiment will determine
whether your hypothesis is true
or false. It should be a fair test.
Test with an
Experiment
You make it fair by changing
only one variable at a time.
You should also repeat your experiments
several times to make sure that the first
results you got were not due to chance.
The Scientific Method
After experiment is complete, compile your
data and analyze it to see if you can
support your claims with evidence.
Claims & Evidence
Remember – Extraordinary claims
require extraordinary evidence
Hypothesis
was correct
Go to
next step
Draw Conclusions
Hypothesis
was incorrect
Determine why,
revise hypothesis or
revise experiment,
repeat experiment
The Scientific Method
Once your work is
complete, write up your
experiment in the proper
format.
Report Results
In our case, that will
be a lab report.
We will discuss
how to write the
lab report later.
Experimental Design
Variables – Factor(s) that are changed in an experiment
Remember that a well-written hypothesis is
an “If…., then…” statement:
“If I do this, then that will happen.”
The “this” is the variable that you will change.
The “that” is the variable that changes when you change the “this.”
Confused?
Let’s give them more proper names and
take a closer look at each one.
Experimental Design
Variables 101
Independent (manipulated) 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 (responding) 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 Design
Variables 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….
Question
How much water flows
through a faucet at
different openings?
Independent Variable Dependent Variables
(What I change)
(What I observe)
Water faucet opening
(closed, half open, fully
open)
Controlled Variables
(What I keep the
same)
Amount of water flowing
* The Faucet
measured in liters per
* Water pressure, or
minute
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."
Does heating a cup of
Temperature of the
water allow it to dissolve water measured in
more sugar?
degrees Centigrade
Amount of sugar that
dissolves completely
measured in grams
* 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."
Question
Which AA battery maintains its voltage for the longest period of time in low, medium,
and high current drain devices?
Hypothesis
Hypothesis: As I test for increasingly longer periods of time, the Energizer AA battery
will maintain a higher voltage than other batteries.
Variables
Independent Variable - Time, how long each battery operates
Dependent Variable - Voltage
Experimental Group
Controlled Variables for Each Group
Low current drain
Same portable CD player
Play the same music track
Play at the same volume level
Medium current drain
Identical flashlight
Identical light bulb
High current drain
Same camera flash
All groups
Battery size (AA)
Constant temperature (A battery works better at a warm temperature.)
What Makes for
Good Variables?
If you have
good Variables,
you should be
able to answer
"Yes" to every
question below
Variables Checklist
Yes / No
Is the independent variable measurable?
Yes / No
Can you change the independent variable during the experiment?
Yes / No
Have you identified all relevant dependent variables, and are they all
caused by and dependent on the independent variable?
Yes / No
Are all dependent variable(s) measurable?
Yes / No
Have you identified all relevant controlled variables?
Yes / No
Can all controlled variables be held at a steady value during the
experiment?
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 is the independent variable?
What is the dependent variable?
What should Sponge Bob’s conclusion be?
Patty Power
Which people are in the control group?
Group B
What is the independent variable?
New sauce
What is the dependent variable?
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
What is the independent variable?
Cures (Seaweed and Dr. Kelp)
What is the dependent variable?
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.