Take My Word For It

• The Earth is the center of the universe.• The sun revolves around the Earth.• All matter is made up of 4 elements: fire, water, earth, & air.• Objects of different masses fall at different rates.• The Vietnam war was about preventing the spread of communism.• Hugo Chavez was a dictator.• High-fructose corn syrup is a safe alternative.

– So is saccharine, and Nutrasweet, and sucralose, and dextrose

• Sadaam Hussein had weapons of mass destruction.• Milk is just as safe today as it was 50 years ago.• GMO’s pose no threat to your health.• 7-up is made with 100% “all natural” ingredients.

Warmup Discussion Answers

• The world was once thought to be flat. Discuss with a partner the following questions and answer: [1 min]

1.Why did people believe this?

2.What caused some to not believe this?

3.What is it about people that causes someone to reject popular thoughts?

4.Is this behavior good or bad for society?

The Scientific Method• Every day you most likely experience something that

makes you wonder…– Why?– How?

• Sometimes you may not believe something someone tells or sells you.– A positive behavior called skepticism.

• If you can’t look up the answer how would you find a solution?

• What technique could you use to try and get the answer?

• The most highly effective technique you could use is the one that has been used by scientists for thousands of years….

Using A Scientific Approach• Objectives:

– Define & describe the steps in the scientific method.

– Explain the groups and variables in a controlled experiment.

– Compare and contrast scientific theories and scientific laws.

– Define & explain the importance of models in science.

Using A Scientific Approach•Vocabulary:

– Scientific method– Observation– Hypothesis– Control group– Experimental group – Dependent variable– Independent variable– Scientific theory– Scientific law– Model

The Scientific Method

• The Scientific Method is a step-by-step approach to problem solving.

• Empirical science is attributed to Aristotle, however Muslim scientists in the 10th – 14th centuries (most notably al-Haytham) were the first ones to use the basic approach to problem solving.

• Used correctly, the scientific method can help you solve problems of all sorts, from personal to physical.

Your 1st “Handout” (like I have on the board). We’ll fill it in as we go.

Make a claim

Using A Scientific Approach

•Scientific Methods:– It is an organized plan for gathering,

organizing, and communicating information

– The goal of any scientific method is to solve a problem or to better understand an observed event.

Beginning a Scientific Investigation

• The 1st Step…• Observation: is information that you obtain

through your senses.• Observation is the act of noting or perceiving

objects or events using the senses.

• Observation takes interest and patience.• It takes care but a desire to know WHY?

• Be careful though, objects can be confusing and individual objects are really dependent upon their surroundings.…

YOUR EYES ARE STUPID: http://youtu.be/dJyvcNmYwr4

Follow the dots.

Now stare at the cross.

More

There’s A Man In Here, But Where?

Count How Many People are in the Picture

Clouds Are Beautiful

Observe the Facts• Read:• Christie comes into class and sits in her regular

seat in the front row. The teacher walks in, writes his name on the chalkboard, picks up the attendance book, and calls out the students' names to see who is present. Then he points to Christie and says, "If anyone has any assigned homework from last night, please give it to this girl now.“

• Name all you observe from the following scenario?• What is the situation?

Answer• From the facts, you can infer that the

teacher is a substitute teacher. – Why? He wrote his name, probably because the

students didn't know who he was. If he were the regular teacher, he'd probably have known Christie's name and not called her "this girl." And he's unsure if students had homework from the day before, probably assigned by their regular teacher.

• Without all the facts it’s hard to make decisions…so we need to ask questions.

Using A Scientific Approach• Observations leads to questions.

– You see lightning in a storm.– You might wonder, “What temperature is it?”– An apple hits you in the head as you sit under it.– You ponder, “Why do apples fall?”– You can’t eat raw eggs so you cook them.– You ask, “Why do eggs become solid when they are

boiled?”– Soaps come in all colors.– But you notice, “Why does soap always lather white

even though it comes in a bunch of other colors?”– The genes for hair are all the same.– But you ask, “Why is some hair soft and other hair

rough?”– You get a candy bar from the store.– You say, “Dang this chocolate's good! I wonder

why.”

Using A Scientific Approach• Making observations leads to questions.• The 2nd Step…• Form a Hypothesis:

– A hypothesis is a possible answer to a question that CAN BE SCIENTIFICALLY TESTED!• In other words, A hypothesis is a prediction

that can be tested by observation or experimentation.

• A hypothesis is NOT JUST AN EDUCATED GUESS!

– It is useful to make create a hypothesis as an ‘if then’ statement.

Scientific Method: Hypothesis

•Hypothesis examples…•Which is best?

– Chocolate is sweet b/c of sugar.– If I take sugar out of a chocolate

recipe then the resulting candy will not be sweet.

– Candy is sweet because it makes me happy.

Examine the Hypothesis

• What are the parts of a good hypothesis?…

Something that’s changed

Compared to something that’s known

The prediction

The measurable outcome

• The 3rd Step…• Design & Conduct a Controlled Experiment:• In testing a hypothesis one must conduct a

well planned, CONTROLLED experiment. • A controlled experiment is one that is

designed so that only one variable (the independent variable) is changed at a time.– What is a variable?

• It’s a factor or value that can change or has multiple values.

• *The independent variable may be called the “manipulated variable” in your book.

Using A Scientific Approach

Using A Scientific Approach• Good Experiments have TWO Groups• Control Group:

– This group is the predictable standard– This group has expected results– Ex. Chocolate candy bar made from the original

recipe…you know how the chocolate is going to taste.

• Experimental Group:– This group has ONE and only ONE variable

changed (related to the hypothesis) to cause a measurable change different from the control group.

– Ex. Chocolate that has been made w/out sugar…you aren’t really sure how the chocolate is going to taste but you’re pretty sure.

Which is the Control,Which is the Experimental?

Kisses Batch #1, Normal Kisses Batch #2, No Sugar

Using A Scientific Approach• More on experimentation variables:

– Experiments have variables.– Independent Variables (aka manipulated

variables) are changes that are directly caused by the experimenter (you.)

• Ex. Amount of sugar added to candy

– Dependent Variables (aka responding variables) are changes that occur due to independent variables.

• These are the values that can be measured!• Ex. Candy is not as good b/c of lack of sugar

– In order to compare these two variables’ results must differ from the control.

Identify Control GroupHypothesis: If we use broadleaf weed killer, then the dandelions will die.• Experimental Control:

– You have two flower beds that are exactly the same, they both contain the same type of dandelion, a broadleaf weed.

– The bed on the left is watered everyday.– The bed on the right is watered everyday and sprayed with weed killer

everyday.• This is the one thing that’s changed.

– Eventually the dandelion in the bed on the right dies.– Which bed is the control group?

BothWatered normally

Same SoilSame Sunlight

Weed Killer AddedThis is the only thing different

Using A Scientific Approach

• What would be a good test for my chocolate hypothesis?

• In this case we could make a few batches of chocolate and have people taste test it.

Using A Scientific Approach

• (3rd Step): Gathering Data• In the case of all experiments, the most

important step is to gather reliable data.– Data is any information from your experiment that you

collect.• Can be numbers or polls or other.

– It must be accurate & precise as possible.– There must be enough data. (“In Triplicate”)– It must be neat.– It must not be biased.

• = shouldn’t be employed or paid by Hershey

• The 4th Step:• Data is analyzed to draw conclusions.

– You will need to take a look at data to make a decision on what it tells you.

Using A Scientific Approach

Using A Scientific Approach

• What does the data tell you?• For our example with the chocolate

we will gather tables of the preference between the control and experimental groups.

• If we have taken enough reliable, accurate, unbiased data then we should be able to make a decision.

Chocolate Taste TestsDecision: does our data support our

hypothesis?

Trial Data: out of 100

A B

Trial 1 95 5

Trial 2 75 25

Trial 3 85 15

Poll

op

inio

n #

Vote

sW

hic

h c

hoco

late

is

sweete

r

Chocolate A B A B A BTrial 1 2 3

A = SugarB = No Sugar

Using A Scientific Approach• Drawing Conclusions:• When drawing a conclusion we must consider the

hypothesis. What was the hypothesis? – If I remove chocolate from a recipe then it will not be as

good.

• If your conclusion supports the hypothesis then you have performed one good experiment.– You could compare with similar tests, run another test, or

repeat the same test over to be sure.

• If you conclusions do not support the hypothesis then you must revise your experiment and test a new variable.– How would this happen?– Maybe cocoa actually is the sweetening agent.

Using A Scientific Approach

• Usually one experiment isn’t enough to draw a definitive conclusion so multiple trials should be ran with the same experiment.– In our case we should run several trials,

repeating the experiment exactly with different polls.

– The data should be illustrated in a graph to help interpret the results.

– See the bar graph on the board.

Control GroupPredictable standard = the group where you expect the results!

Experimental GroupExactly the same as the control group except for one thing…the independent variable.

What are the two groups in the experiment?

You measure the dependent variables in the experiment.

What Could Happen:

Option 1: the data doesn’t support the hypothesis.

What Could Happen:

Option 1: the data does support the hypothesis.

After the Conclusion

•After validating a hypothesis several times you can come to a conclusion.

•This is also called “making a claim”.– In our case we could claim that sugar makes

chocolate sweet.

•But one study usually isn’t enough.•A good scientist will retest multiple times

testing a variety of similar hypotheses.

Make A Claim

Developing a Theory:

• After validating many similar hypotheses you then come up with a theory that explains the result of your experiments.

• A scientific theory is a well tested explanation for a set of observations or experimental results.

Make a claim

Scientific Theories

• One drawback to theories is that scientific theories are never completely proven.

• Ex: The theory of relativity• Ex: The theory of evolution• Ex: The theory that chocolate is the

best candy on Earth.

Using A Scientific Approach•Scientific laws

– Scientific laws are patterns in nature that don’t need to be proven.

– summarizes an observed pattern found in nature without needing to explain it anymore (it’s a constant – like death and taxes). The explanation of such a pattern is provided by many scientific theories.

– Law of Gravity - Newton– Law of Thermodynamics - Hess– Law of Electricity - Ohm– Conservation of mass - Lavoisier

CheckPointDescribe what the difference is between

scientific hypotheses, theories, & laws.• Hypotheses are narrow

– They are reasonable ideas to answer questions for observed singular events

• Theory is a well tested explanation for patterns observed in nature– Theory of evolution = change happens over time

• A law describes patterns in nature – A law doesn't need testing or validation anymore– The law of gravity.

Scientific Models• After you prove a law, make a claim, or develop a

theory, you should make a model.• What is a Model?• Scientific models are physical or mental

representation of an object or an event• What is the Purpose of a Scientific Model?• Models make it easier to understand things that

are very complex, very large, very small or difficult to observe directly.

– By illustrating the theory/law/phenomenon in 2- or 3-D

Make a claim Model

Scientific Models

• Example: When designing a new airplane the designer will often make a computer model demonstrating how the airplane should handle air current.

• What would be a model for:– The solar system?– The earth’s rotation?– Water cycle?– An atom?– Macroeconomics? Just kidding….

Scientific Models

Make a claim Model

Overview

You have a problem…

"Early to bed, early to rise makes a man healthy, wealthy and wise," said Ben Franklin. But does this adage apply to teenagers? Research in the 1990s found that later sleep and wake patterns among adolescents are biologically determined; the natural tendency for teenagers is to stay up late at night and wake up later in the morning. This research indicates that school bells that ring as early as 7:00 a.m. in many parts of the country stand in stark contrast [the start times contradict] with adolescents' sleep patterns and needs.

Evidence suggests that teenagers are indeed seriously sleep deprived. A recent poll conducted by the National Sleep Foundation found that 60% of children under the age of 18 complained of being tired during the day, according to their parents, and 15% said they fell asleep at school during the year.”

http://www.sleepfoundation.org/article/sleep-topics/school-start-time-and-sleep

How Would You Prove It?

• High school starts early in the morning but there are highly educated researchers that claim that if high school was started just 1.5 hours later students’ scores and health would increase.

• In your groups develop a good strategy that you could use to help prove that sleep does in fact help students in their studies.

• You will have 5 minutes then we will discuss.

Practice with Scientific Method•Objectives:•Identify aspects (hypotheses, controls,

variables, conclusions) of the scientific method. – Whole class = Simpson’s examples

•Identify aspects of the scientific method in groups. – SpongeBob Worksheet– Each example is worth 8 pts. – 8 x 6 examples = 48pts. 2 pts. for your

name.