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Scientific method

In science we ask and refine questions that lead to explanations of how the world works, and which can be empirically tested. This process is often called the scientific method.

Critical thinking paper!

I. What science is not

Science is not a belief or a position.

Science is a method that allows us to test claims.

In middle school we learn steps, showing how science works:

Ask a Question Research Hypothesis flowchart

In high school we move beyond this to a deeper understanding:

Science doesn’t actually work like a recipe:

How does science really work?

  • scientists don’t work by themselves: they share ideas with peers.

  • sharing ideas often causes us to change our hypothesis.

  • Outside of science, changing ideas is sometimes perceived as being bad. Called “flip flopping”

  • In science, changing one’s position based on evidence is a strength.

    Neil Degrasse Tyson

    Neil Degrasse Tyson

  • Creativity and imagination abound at every step.

  • Science can be as creative as art and literature.  The difference is that our ideas are then against reality.

  • The scientific method is not a linear path.

II. What Science is

What is the “first step” of the scientific method? There is none.

Instead, each person exploring science already has background knowledge of how the world works. Students know the names of thousands of objects, and how they appear to work. They see the sun and moon move across the sky in patterns; they see animals have offspring; they see people put their feet on pedals, and by moving them thus move a chain, which causes bicycle wheels to spin. Cause-and-effect. So even before formally learning science, people have a massive database of knowledge and observations.

Once in a while, a problem may appear, giving us reason to solve it…

Once in a while, we observe something which contradicts our view of the world – we ask, how this can be?

Once in a while, someone asks us a question that we had never considered before…

In any of these ways, science begins. All are ‘the first step’ of the scientific method. As you may imagine, at any point during the process, any of this may happen again.

Scientific Method coming up with an idea

from “Understanding Science”,

The University of California Museum of Paleontology, Berkeley (c)

III. Science only works for scientific questions.

Science doesn’t answer questions about value, beauty, meaning or ethics. Science does not address supernatural claims.

Science has limits: Here is what science does not do.

IV. Examples of claims that can be analyzed with science

  1. NASA scientists found chemical patterns that may have been possible signs of life on Mar. This happened in 1976 during the Viking missions.  In the late 1990s, studies of a Martian meteorite provided evidence that microscopic, bacteria-like life on Mars may have existed.  Did simple forms of life once lived on Mars? Does bacterial life live in the Martian soil today?
  1. Many people in Scotland reported a creature swimming in Loch Ness (a large freshwater lake in the Scottish Highlands.)
    A few blurry photographs have been taken of an object in the water. Newspapers named this supposed creature “the Loch Ness Monster”. Are there unknown, large sea monsters living in this lake?
  1. In the 1970’s doctors created an oral pill, Loniten, to control high blood pressure. It works by dilating the blood vessels, so blood can flow better. One of the side effects that patients reported was excess body hair growth. Could this be the first drug in to grow more hair?http://en.wikipedia.org/wiki/Androgenic_alopecia
    Male pattern baldness minoxidilMinoxidil molcule
  1. Charles Darwin (1809 –1882) was an English naturalist. Traveling across the world, he discovered evidence that today’s animals are modified versions of animals that lived in the past; he discovered that many forms of life have descended over time from common ancestors. He came up with an idea called evolution by natural selection, to explain how all life developed. Has life on Earth evolved from earlier forms of life?
    Charles Darwin quote

How can we tell which of these claims are true? We need a process to discover whether or not these claims are correct.

V. Science is not a belief or a position

Science is a process used to approach claims – to see if the claim is correct or not. We approach claims skeptically: That doesn’t mean that that we don’t believe anything. Rather, it means we don’t accept a claim unless we are given compelling evidence. Skepticism is a provisional approach to claims.

skeptic no amount of belief

Calvin here clearly needs to come up with a testable hypothesis:calvinandhobbes toast

VI. Examples

Suppose that your car will not start. Create a hypothesis.
“My car does not start because the battery is low.”


* If the headlight switch was left on for a long time, this would result in a battery drain.

* The starter will make a certain type of sound if the battery is dead (many of you will know what I am talking about here.)

  • If the battery is dead, the voltage across the battery terminals will be much lower than normal.

Experiment: Test to see if predictions are verified or refuted

* Check whether the lights were left on.

* Insert the key and turn it; listen to the sound of the engine.

* With the right device, check the voltage of the battery.

Evaluate the results: If predictions are verified, then our hypothesis was confirmed. But if out predictions are refuted, then our hypothesis must be rejected. Then we must come up with another hypothesis, e.g.  “The starter is broken”, or “Out of gas”, etc. Then run new experiments to evaluate the new hypothesis.


VII. Writing a Hypothesis

Your hypothesis must be something you can test.

“If I do [this], then [that] will happen.”

If I [give flower seeds an organic fertilizer] then [they will sprout faster than those fed a synthetic fertilizer].


BAD – Planets move around the Sun at different speeds, because different angels push them.

GOOD – Planets move around the Sun at different speeds, because at different distances from the Sun, they experience a different amount of pull from the Sun’s gravity.

There is no way to test the first statement; therefore it is not a scientific hypothesis.

http://www.slideshare.net/sfharb/hypothesis-4858923 Charles Hart Middle School

Charles Hart Middle School

VIII. Peer Review


Scientists describe their methods and results: They publish in peer‑reviewed journals. Others can then repeat the work, and offer constructive criticism.

If others get the same result, then we can say with a higher degree of certainty that our hypothesis is correct,

If others get different results, then something might be wrong or overlooked.

Peer review is necessary – only by working with others can we be sure that our results are trustworthy.

VIII. Science is necessary because we can’t always trust our senses

Humans occasionally perceive things that are not really there:

Apophenia /æpɵˈfiːniə/ is a human tendency of perceiving patterns or connections in random or meaningless information.

Pareidolia (/pærɨˈdoʊliə/ parr-i-doh-lee-ə) is the visual or auditory form of apophenia. People may perceive patterns in images and sounds, that really are not there. Common examples are perceived images of animals, faces, or objects in cloud formations; the “man in the moon”; and claims of hidden messages within recorded music played in reverse.

The Rorschach inkblot test is a famous example of psychologists attempting to use pareidolia, in an attempt to gain insight into a person’s mental state. (However it should be noted that the Rorschach test itself is no longer widely considered to produce useful informationn.)

The clustering illusion is the tendency to erroneously consider the inevitable “streaks” or “clusters” arising in small samples from random distributions to be non-random.

Confirmation bias is the tendency to search for, interpret, and favor information in a way that confirms one’s beliefs, while giving disproportionately less attention to information that contradicts it

Objectives: 2016 Massachusetts Science and Technology/Engineering Standards
Students will be able to:
* plan and conduct an investigation, including deciding on the types, amount, and accuracy of data needed to produce reliable measurements, and consider limitations on the precision of the data
* apply scientific reasoning, theory, and/or models to link evidence to the claims and assess the extent to which the reasoning and data support the explanation or conclusion;
* respectfully provide and/or receive critiques on scientific arguments by probing reasoning and evidence and challenging ideas and conclusions, and determining what additional information is required to solve contradictions
* evaluate the validity and reliability of and/or synthesize multiple claims, methods, and/or designs that appear in scientific and technical texts or media, verifying the data when possible.

A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (2012)
Implementation: Curriculum, Instruction, Teacher Development, and Assessment
“Through discussion and reflection, students can come to realize that scientific inquiry embodies a set of values. These values include respect for the importance of logical thinking, precision, open-mindedness, objectivity, skepticism, and a requirement for transparent research procedures and honest reporting of findings.”

Next Generation Science Standards: Science & Engineering Practices
● Ask questions that arise from careful observation of phenomena, or unexpected results, to clarify and/or seek additional information.
● Ask questions that arise from examining models or a theory, to clarify and/or seek additional information and relationships.
● Ask questions to determine relationships, including quantitative relationships, between independent and dependent variables.
● Ask questions to clarify and refine a model, an explanation, or an engineering problem.
● Evaluate a question to determine if it is testable and relevant.
● Ask questions that can be investigated within the scope of the school laboratory, research facilities, or field (e.g., outdoor environment) with available resources and, when appropriate, frame a hypothesis based on a model or theory.
● Ask and/or evaluate questions that challenge the premise(s) of an argument, the interpretation of a data set, or the suitability of the design

MA 2016 Science and technology

Appendix I Science and Engineering Practices Progression Matrix

Science and engineering practices include the skills necessary to engage in scientific inquiry and engineering design. It is necessary to teach these so students develop an understanding and facility with the practices in appropriate contexts. The Framework for K-12 Science Education (NRC, 2012) identifies eight essential science and engineering practices:

1. Asking questions (for science) and defining problems (for engineering).
2. Developing and using models.
3. Planning and carrying out investigations.
4. Analyzing and interpreting data.
5. Using mathematics and computational thinking.
6. Constructing explanations (for science) and designing solutions (for engineering).
7. Engaging in argument from evidence.
8. Obtaining, evaluating, and communicating information.

Scientific inquiry and engineering design are dynamic and complex processes. Each requires engaging in a range of science and engineering practices to analyze and understand the natural and designed world. They are not defined by a linear, step-by-step approach. While students may learn and engage in distinct practices through their education, they should have periodic opportunities at each grade level to experience the holistic and dynamic processes represented below and described in the subsequent two pages… http://www.doe.mass.edu/frameworks/scitech/2016-04.pdf

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