How to “Think like a Scientist”

DAY 1Claims, Evidence,

and Reasoning

Bellwork – Day 1

Explain how you would go about trying to change someone’s mind. (3-4 complete sentences required)

What do Scientists do?

1. They make observations – both qualitatively using their senses and quantitatively using instruments to measure data.

2. They come up with questions that guide their experiments.

3. They design experiments, collect data, form conclusions and then use that information to come up with more questions.

4. They debate, argue, and question everything!

Claims, Evidence, & Reasoning

Claim: Something you think is true

Evidence: The DATA (numbers) that made you think it was true

Reasoning: What about the evidence made you think it was true – use scientific principles to explain HOW the evidence supports your claim.

CER Example

Johnny is going through puberty. (CLAIM)

Johnny is 14 and has grown 4 inches over the last 6 months, has started growing a mustache and his voice has changed. (EVIDENCE)

Puberty is a time when boys grow facial hair, experience voice changes and have tremendous growth spurts. Therefore, Johnny must be going through puberty. (REASONING)

Practice matching the Phrase with the correct Vocabulary Term

Phrase Vocabulary Term

1. My Mom is mad. Reasoning

2. She is frowning. Claim

3. She was frowning yesterday Evidence when she said, “I am mad!” 

CORRECT ANSWERS

Phrase Vocabulary Term

1. My Mom is mad. CLAIM Reasoning

2. She is frowning. EVIDENCE Claim

3. She was frowning yesterday Evidence when she said, “I am mad!”REASONING

 

Scientific Observations,

Inferences, Theories, and Laws

ObservationObservation InferenceInference

Use your senses to gather information about the natural world

Qualitative: Things you use your 5 senses to observe. What you see, feel, smell, taste, hear.

Quantitative: Measureable observations. Length, width, height, mass, large, heavy, etc.

A statement based on your evidence, SAME as a CLAIM!!

Example: Students who study for tests earn better scores!

Observation vs. Inference

Practice with Observations

List whether these are qualitative or quantitative observations.

1.The plant on the windowsill looks green and healthy.

2.The chemicals in test tube 4 are bubbling and producing an odor.

3.Plant #3 in our experiment grew 8cm over the weekend.

4.When we mixed the two chemicals together in the ziploc bag a gas was produced that inflated the bag.

Answers to Practice with observations

List whether these are qualitative or quantitative observations.

1.The plant on the windowsill looks green and healthy. QUALITATIVE

2.The chemicals in test tube 4 are bubbling and producing an odor. QUALITATIVE

3.Plant #3 in our experiment grew 8cm over the weekend. QUANTITATIVE

4.When we mixed the two chemicals together in the ziploc bag a gas was produced that inflated the bag. QUALITATIVE

Practices with Observations Vs. Inferences

List whether these claims are observations or inferences.

1.Ms. Browning’s loves the color red. 2.There is a science lab in every classroom

building at SGMS.3.Florida State is the best college in Florida.4.Ms. Browning’s 8th grade class has

approximately 20 students.

Answers to Practices with Observations Vs. Inferences

List whether the claims are observations or inferences.

1.Ms. Browning’s loves the color red! INFERENCE2.There is a science lab in every classroom building

at SGMS. OBSERVATION (QUALITATIVE)3.Florida State is the best college in Florida.

INFERENCE4.Ms. Browning’s 8th grade class has

approximately 20 students. OBSERVATION (QUANTITATIVE)

TheoriesTheories LawsLaws

Evidence-based explanation

Describes why things

happen in nature

Used to make predictions and CAN be modified but are rarely discarded(thrown away)

Generalizations or patterns in nature derived from scientific FACT!

Describes what will happen but does NOT explain it!

Usually related to a mathematical equation.

Theories vs. Laws

TheoriesTheories LawsLaws

The Big Bang Theory states that the universe began almost 14 billion years ago with a massive expansion event.

Newton’s three laws of motion form an essential component of modern physics.

Examples of Theories vs. Laws

Newton’s 2nd Law: Force = Mass X Acceleration

Practice with Theories vs. Laws

State whether these sound like theories or laws.

1.The __________ of Evolution is based on evidence that species have changed over time and some species have common bone structures.

2.The ________ of Universal Gravitation states that everything with mass has gravity AND everything with gravity is attracted to everything else with gravity.

Answers to Practice with Theories vs. Laws

State whether these sound like theories or laws.

1.The _THEORY_ of Evolution is based on evidence that species have changed over time and some species have common bone structures.

2.The _LAW__ of Universal Gravitation states that everything with mass has gravity AND everything with gravity is attracted to everything else with gravity.

Scientific Investigations and Models

Models in Scientific Investigations

What role, benefits, and limitations do MODELS play in scientific investigations? Models provide an

opportunity for scientists to investigate the cause and effect of natural events without the cost needed to replicate the actual event.

They are especially beneficial when the thing being studied is either too big (Space) or too small (atoms).

Scientific Method

The scientific method is a way to ask and answer scientific questions by making observations and doing experiments.

Always start with observations that guide questions!

Question or Problem

What are you trying to find out?Also called the PurposeStated in the form of a question.

What MUST you do prior to creating a measureable hypothesis?

What MUST you do prior to creating a measureable hypothesis?

Research, research, research!!!!

Remember a Hypothesis is an EDUCATED prediction of what will happen. You need to have reasons WHY you think the experiment will turn out the way you are predicting it to with your hypothesis.

Hypothesis

A hypothesis is an educated prediction of what the results will show based on previous experiences, ideas and evidence.

A prediction that can be tested !!

A single test can never prove that something is always true, but it could prove that it is not always true.

It is based on research and previous knowledge

Variables

Different factors that can change an experiment

It is very important that you only allow ONE variable to change when conducting an experiment

Why is this so important?

Types of Variables

Independent variable: The thing you are testing. The one and only variable you allow to change.

Dependent Variable: What you measure to compare the results of your test. Should be able to be charted or graphed.

Constant: The variables that you don’t allow to change. What stays the same in each test.

Procedures

Step by step instructions for how to conduct the testing.

Should be detailed enough that someone else could follow them and do exactly what you did.

The experiment should be repeated at least five times for valid results.

Recording Data

Very careful record keeping is essential for valid results.

Use charts or tables to organize data.Records measurements as well as

observations and things you want to remember about what happened.

Analyze the Results

What are your results? What does the data show?

Create charts, tables, and graphs to represent all of your data.

Perform any calculations that will help you determine what the results mean. (i.e. averages, percentages, totals)

What are the possible sources of error? (i.e. inaccurate measurements, contamination, etc.)

Draw Conclusions

What is the answer to your Question based on your results?

Was your hypothesis supported or not? Why or why not?

If you could do this experiment over again what would you do differently next time?

What other experiments could you do to further test this?

Your results are not valid if . . .

They are based on opinions rather than data.You draw conclusions that don’t logically

follow the evidence.Your sample size is too small or is biased.

Recheck and Repeat!Recheck and Repeat! Then . . . .Then . . . .

Check all the calculations and instruments used to measure.

Repeat experiment at least 5 times.

Start questioning again . . . . Why??

Revise your hypothesis and start experimenting again!

What do I do if my hypothesis is not supported with my experiment?

Unit Review Game

A. THE THINGS THAT STAY THE SAME FROM TEST A TO TEST B TO TEST C.

B. THE VARIABLE THAT IS CHANGES FROM TEST A TO TEST B TO TEST C.

C. THE THING THAT NEVER CHANGES

D. THE THING THAT YOU MEASURE

Which of these answers best describes a dependent

variable? 

A. FIELDWORK

B. SCIENTIFIC THEORY

C. SCIENTIFIC LAW

D. EMPIRICAL EVIDENCE

Which term describes a collection of observations on which a scientific explanation is based?

A. SCIENTIFIC THEORIES EXPLAIN WHY SOMETHING HAPPENS, AND SCIENTIFIC LAWS DESCRIBE WHAT HAPPENS.

B. SCIENTIFIC THEORIES REQUIRE SCIENTIFIC EVIDENCE AND SCIENTIFIC LAWS DO NOT.

C. SCIENTIFIC THEORIES ARE BASED ON OBSERVATION, AND SCIENTIFIC LAWS ARE BASED ON OPINIONS.

D. SCIENTIFIC LAWS ARE FREQUENTLY MODIFIED, BUT SCIENTIFIC THEORIES ARE RARELY CHANGED AS NEW INFORMATION BECOMES AVAILABLE.

What is the difference between a scientific theory

and a scientific law?

A. MY SHOE IS SIZE 8

B. MY SHOE IS WHITE

C. MY SHOE IS DIRTY

D. MY SHOE IS STINKY

What is an example of a quantitative observation?

A. THEY ARE BASED UPON FEELINGS.

B. THEY ARE BASED UPON UNGUIDED GUESSES.

C. THEY ARE BASED UPON EVALUATION OF DATA.

D. THEY ARE BASED UPON CAREFUL PLANNING OF EXPERIMENTAL DESIGN.

Which statement best describes the nature of scientific explanations?