Thinking & Working Like A Scientist-6th Grade

What is Science?

Science is the investigation and exploration of natural events and of the new information that results from those investigations.

People use science in their everyday lives and careers for many different things. Ex:

fire fighters’ clothing has been developed and tested to withstand extreme temperatures and not catch fire.

Athletic performance gear

Science involves creativity, not just in designing experiments, but also in creating explanations that fit evidence

Dinosaur Extinction Hypotheses:Asteroid? Volcanism?Climate Change?

Scientific Inquiry

When scientists conduct scientific investigations, they use scientific inquiry.

Scientific inquiry- a process that uses a set of skills to answer questions or to test ideas about the natural world. Scientists begin scientific inquiry with

making observations and inferences

Evidence gained from observation is called empirical evidence.

Observation Inference

The act of using one or more of your senses to gather information and taking note of what occurs.

Qualitative: Things you use your 5 senses to observe. What you see, feel, smell, taste, hear. Not expressed as a number and open to interpretation.

Quantitative: Measureable observations. Length, width, height, mass, large, heavy, etc.(Expressed as a number)

A logical explanation of an observation that is drawn from prior knowledge or experience

Example: Students who study for tests earn better scores!

Observation vs. Inference

A. MY SHOE IS SIZE 6

B. MY SHOE IS WHITE

C. MY SHOE IS DIRTY

D. MY SHOE IS STINKY

What is an example of a quantitative observation?

Question or Problem

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

Hypothesis

Hypothesis-a possible explanation for an observation that can be tested by scientific investigations

It is based on research and previous knowledge

Often used to make a prediction which is a statement of what will happen next in a sequence of events. “If______ Then “ statement.

Ex: If the there is an increase of rainfall, then rate of erosion will increase.

Testing a Hypothesis

Scientists test a hypothesis by doing one or more of these steps:

Designing a controlled experiment Make a model Gather and evaluate evidence or research Collecting Data/Record Observations

Designing a Controlled Experiment

To design a controlled experiment, scientists identify factors that might affect the outcome of the experiment.

Any factor that has more than one value is called a variable.

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.

Control: Used for comparison

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?

 

Writing ResponseMr. Krabbs 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?

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.(Replication). If scientific explanations are replicable, they are more valid and reliable.

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

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

Scientists draw conclusions based on relationships among their data; a conclusion is a summary of the information gained from testing a hypothesis.

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

Was your hypothesis supported by your experimental results? 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! 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 by my experimental results?

RESULTS OF SCIENCE

A scientific investigation can result in: New technology-practical use of scientific knowledge,

especially for industrial or commercial use. New materials, such as those developed New explanations as to why or how something occurs

Models

A Model is a representation of an object, process, system, or event that is similar to the original object or idea.

They scientists better understand objects/ideas; allow hands-on contact with matter that is too small, too large, too far away, too dangerous, or too expensive to build

Models can be: Physical/visual Conceptual Mathematical

Not all scientific knowledge is derived from experimentationExperiment – involves identification and control of variables Independent variable/test variable/manipulated

variable Dependent variable/outcome variable/responding

variable Controlled variables

Field Study – observe a natural habitat without manipulating variables

Simulation – imitating a real situation or process

EXPERIMENT VS. OTHER FORMS OF SCIENTIFIC INVESTIGATION

Theories and Laws

Is it a Theory?

Which statement(s) do you think BEST apply to scientific theories?A. Theories include observationsB. Theories are “hunches” scientists haveC. Theories can include personal beliefs or opinionsD. Theories have been tested many timesE. Theories are incomplete, temporary ideasF. A theory never changesG. Theories are inferred explanations, strongly supported

by evidenceH. A scientific law has been proven and a theory has notI. Theories are used to make predictionsJ. Laws are more important to science than theories

Adapted from Keeley, Page. Volume 3: Uncovering Student Ideas in Science. 2008.

Is it a Theory?

Which statement(s) do you think BEST apply to scientific theories?A. Theories include observationsB. Theories are “hunches” scientists haveC. Theories can include personal beliefs or opinionsD. Theories have been tested many timesE. Theories are incomplete, temporary ideasF. A theory never changesG. Theories are inferred explanations, strongly supported

by evidenceH. A scientific law has been proven and a theory has notI. Theories are used to make predictionsJ. Laws are more important to science than theories

Scientific Theory = Explanation

Evidence-based explanation based on observations of events

Tested and supported with multiple lines of evidence

Widely accepted and strongly supported by the scientific community

Can be used to make predictions

Can be modified if new evidence becomes available

Examples:Cell TheoryPlate Tectonics TheoryAtomic Theory

Scientific Law = Statement Patterns in nature derived from scientific fact

Describe how the natural world behaves under certain conditions

Describes an event but it does NOT explain it!

Scientific Laws vs. Societal laws. They both tell us how things should work Scientific Laws cannot be intentionally broken Laws of society vary from place to place. Scientific Laws are the same everywhere.

EXAMPLES OF SCIENTIFIC LAWS

Newton’s Laws of Motion

Universal Law of Gravity

Law of Conservation of Energy

Law of Conservation of Mass

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?

Laws describe what

and

Theories describe why

Remember…Scientific knowledge can change as new evidence or interpretations arise

Theories may be modified, but are rarely discarded

It was a widely held belief that the Earth was the center of the Universe until the 1500s