Transcript What is Science? - Fulton County Schools

Unit 1 – Lecture 2
What is Science?
 Science is an organized way of attempting to
understand the natural world, structurally and
operationally.
 We are always
 looking for ways to improve our quality of life
 trying to understand how systems work
 attempting to improve on an existing system
The need for “proof”
 Evidence is based on observations.
 Information gathered using the senses during an
observation is called data (sing. datum).
Data
 Data can be qualitative or quantitative.
 Qualitative – no specific number, rather a
comparison or estimate
 ex. big, blue, some, herd, bunch
 Quantitative – specific number given in an attempt
at exacting detail
 ex. 21.6m, 662 miles, 13, 17 reindeer
Discuss
Quantitative or Qualitative?
 Give me some of your french fries.
 Get me a dozen eggs.
 Admission to the game is only a few dollars.
 There are nine geese on the lake.
 Go out and get some firewood for the bonfire tonight.
Reasoning
 Deductive Reasoning – general quality  specific case
 using general rule about something to come to a
specific conclusion about something else.
Apples are red.
Apples are firm.
This is firm and red.
This is an apple.
This is firm but not red.
This is not an apple.
HONORS ONLY
Reasoning
 Inductive Reasoning – specific qualities  general case
 arriving at a conclusion based on specific observations
After examining a dozen
oranges, one should know
enough to be able to inductively
reason what this is below.
HONORS ONLY
Reasoning
 Inference – an estimation or prediction based on
previous experiences or observations
 You can infer about whether or
not a fish with large, sharp teeth
eats other fish because of your
previous experiences or observations of fish with large, sharp
teeth.
HONORS ONLY
Hypotheses
 Hypothesis – an “educated guess” [a testable prediction]
 if, then [cause/effect] format
 contains IV & DV
 always a statement – NEVER a question
 predicts outcome of experiment
 there may or may not be an underlying knowledge
about the hypothesis
 ex: As I test for increasingly long periods of time,
the Energizer AA battery will maintain a higher
voltage than other batteries.
Theory
 Theory – the BEST possible scientific explanation of an
experience or observation in nature.
 sometimes called a “well-tested hypothesis” BUT
may not be able to be tested
 if not able to be tested, is supported by relative
experiments
 there is an underlying knowledge about a theory,
both observationally and experimentally.
Scientific Law
 Always true
 Can not be circumvented or broken
Hypothesis, Theory, or Law?
 Birds may have descended from dinosaurs.
 Energy can be transformed from one form to
another.
 Dogs will eat all kinds of cheese.
 Gravity affects all objects in the universe.
 “Tide” brand laundry detergent gets your clothes
cleaner than others.
Ethics & Values in Science
 There is no “right” “wrong” “good” “evil” in science
itself, but the applications can be as such to others.
 Bias – a predisposition for or against something
 not based on logic or reason
 Ethics - whether or not an action or plan is
considered right or wrong by a group or society.
 Values - help you decide whether or not
something is ethical [differ from person to
person]
 charging for cures, man vs. environment…etc.
The Scientific Method
An organized procedure to determine whether or not a
statement (or idea) is valid.
Every scientist follows the scientific method, but not
every scientist uses all of the scientific method.
The Scientific Method
 a tool used to solve problems
 used by EVERYONE – not just scientists
 Steps in the Scientific Method
•
•
•
•
Observe
develop Problem
……Statement
collect Background
…… Info
form Hypothesis
Experiment
collect Data
analyze Data
form Conclusion
• perform
•
•
•
Discuss
 Which step of the Scientific Method supports or
rejects the hypothesis?
 Which step of the Scientific Method has us research
the work done on our question by others?
 Which step of the Scientific Method has a
restatement of the Hypothesis?
 Which step of the Scientific Method has us make
graphs and charts to determine the outcome of our
Experiments?
 Which step of the Scientific Method is a testable
statement?
Hypotheses
 Forming a Hypothesis
 If, Then format
 statement, NOT a question
 contains IV and DV
 predicts specific outcome of the experiment
 what type of change are you making?
 what type of change are do you predict you’ll see?
abbreviation [used frequently] for change = Δ
Hypotheses – cont’d
 Types of Hypotheses
 Hypothesis – predicts change in the results
between the control & experimental groups
 If [change] in IV, then [change] in DV
 Null Hypothesis - predicts no change in the
results between the groups
 If change in IV, then NO CHANGE in DV.
Test Groups
Two different groups in an experiment:
 Control Group - group that does not receive the
treatment or change
 functions as a standard by which you can measure
the results of your experiment
 we know that what we are testing is NOT affecting
this group
 keep as many of the variables the same as possible
Test Groups – cont’d
Two different groups in an experiment:
 Experimental Group – group in the experiment which
receives the change/treatment
 what we are testing IS affecting this group
 only one variable is changed [what we’re testing]
Variables
 Constants [control variables] - kept the same from
group to group, trial to trial
 No Constants, No Confidence
 Experimental Variable – the condition changed from
the control group to cause a response
 aka: the IV or the Manipulated variable
 “I control the IV”
Variables
 Dependant Variable - the outcome of the changed
variable
 changes because of a change in the IV/experimental
group
 also called the responsive variable
Reproducible Results
 To be considered valid, a successful experiment must
be replicable (repeatable).
 Scientists often publish their lab reports in journals
so that other scientists can try these experiments.
Check Your Results
 If the Results and Conclusions do not support your
hypothesis, check your procedures for any sources of
error.
 Sources of error can be included in laboratory report
to help other scientists determine what may have gone
wrong in your experiment.
 Human error [I knocked over the beaker] is NOT a
source for error or suggestion for improvement.
Discuss
 Which variable do you make certain does not
change for the experiment?
 Anything that may have affected your data in an
experiment should be described under which part
of a lab report?
 Any data which does not seem to follow the other
data in an experiment could be caused by
 Which variable do you change for the experiment?
Practice – Example
Mr. Smith wants to make Jacksonville a nicer place to
live. He has created a new fuel that he thinks will
reduce the production of air pollutants associated with
burning trash. He recruits 100 customers with a
history of burning trash. He has 50 of them (Group A)
use the new fuel. The other 50 (Group B) use the
original fuel. Both groups were told they were getting
the new fuel. After 2 hours of burning trash, 30
customers in group A reported having fewer air
pollution, like smoke. Group B had 8 customers that
reported better results.
Practice – Example 1
 Which group is the control group and why?
 Independent variable?
 Dependent variable?
 What is Mr. Smiths’ conclusion?
 Why do you think 8 people in group B reported having
better results?
Practice – Example 2
 John notices that his friend Gary is suffering from
smelly feet disorder, which occurs when the feet
develop a nasty infection and give off a horrible odor.
John’s friend Patrick tells him that rubbing seaweed on
the feet is the perfect cure, while Sandy says that
drinking lemon juice will be a better cure. Gary
decides to test this cure by rubbing his feet with
seaweed for 1 week & drinking lemon juice. After 1
week of treatment, the foot odor is gone.
Practice – Example 2
 What is the initial observation?
 Manipulated variable?
 Responsive variable?
Homework
 Vocab due tomorrow [ON quiz Mon]
 Equipment cards due Tuesday [CN quiz next Friday]
 complete pages 4-5 – Practice w/ Experimental Design
w/s