Unit 1 – Lecture 2

What is Science?Science is an organized way of attempting to

understand the natural world, structurally and operationally.

We are alwayslooking for ways to improve our quality of

lifetrying to understand how systems workattempting 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).

DataData can be qualitative or quantitative.

Qualitative – no specific number, rather a comparison or estimateex. big, blue, some, herd, bunch

Quantitative – specific number given in an attempt at exacting detailex. 21.6m, 662 miles, 13, 17 reindeer

DiscussQuantitative 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.

ReasoningDeductive Reasoning – general quality

specific caseusing general rule about something to

come to a specific conclusion about something else.

Apples are red.

Apples are firm.

HONORS ONLY

ReasoningInductive Reasoning – specific qualities general

casearriving 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

ReasoningInference – an estimation or prediction based

on previous experiences or observations

You can infer about whether ornot a fish with large, sharp teetheats other fish because of your previous experiences or observa-tions of fish with large, sharp teeth.

HONORS ONLY

HypothesesHypothesis – an “educated guess” [a testable

prediction]if, then [cause/effect] formatcontains IV & DValways a statement – NEVER a questionpredicts 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.

TheoryTheory – 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 LawAlways trueCan 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 ScienceThere 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 reasonEthics - 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 MethodAn 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 Methoda tool used to solve problemsused by EVERYONE – not just scientists

Steps in the Scientific Method

• develop Problem ……Statement

• collect Background …… Info

• form Hypothesis

• perform Experiment• collect Data• analyze Data• form Conclusion

• Observe

DiscussWhich 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?

HypothesesForming a Hypothesis

If, Then formatstatement, NOT a questioncontains IV and DVpredicts 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’dTypes of Hypotheses

Hypothesis – predicts change in the results between the control & experimental groupsIf [change] in IV, then [change] in DV

Null Hypothesis - predicts no change in the results between the groupsIf change in IV, then NO CHANGE in

DV.

Test GroupsTwo different groups in an experiment:Control Group - group that does not receive the

treatment or changefunctions as a standard by which you can

measure the results of your experimentwe know that what we are testing is NOT

affecting this groupkeep as many of the variables the same as

possible

Test Groups – cont’dTwo different groups in an experiment:Experimental Group – group in the

experiment which receives the change/treatmentwhat we are testing IS affecting this grouponly one variable is changed [what we’re

testing]

VariablesConstants [control variables] - kept the same

from group to group, trial to trialNo Constants, No Confidence

Experimental Variable – the condition changed from the control group to cause a responseaka: the IV or the Manipulated variable“I control the IV”

VariablesDependant Variable - the outcome of the

changed variablechanges because of a change in the

IV/experimental groupalso called the responsive variable

Reproducible ResultsTo 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 ResultsIf 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.

DiscussWhich 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?

HomeworkVocab due tomorrow [ON quiz Mon]Equipment cards due Tuesday [CN quiz next

Friday]complete pages 4-5 – Practice w/

Experimental Design w/s