how do you know who i am ? observations construct a hypothesis make predictions test predictions?...

24
How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions? Quality of evidence?

Upload: marissa-clark

Post on 26-Mar-2015

217 views

Category:

Documents


3 download

TRANSCRIPT

Page 1: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions? Quality of evidence?

Page 2: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

How do you solve other problems? Why won’t this stupid lamp work? Observations Hypothesis Experiment Empiric evidence Does bulb work? Rational formation of a theory Regression to other problem solving

strategies.

Page 3: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

A hypothesis is…. a best guess based on available

observations. highly tentative and falsifiable. formed using creativity and imagination. formed using inductive logic.

Page 4: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Inductive logic Form a general rule based on specific

observed instances. “Oh look! A blue mailbox. Perhaps all

mailboxes are blue?”

Page 5: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

A theory is… a hypothesis supported by a body of

empiric evidence. falsifiable but becomes more “robust” as

evidence accumulates. tested or falsified using deductive logic,

but supported by additional induction. never proven.

Page 6: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Deductive logic Following a general rule to its logical

conclusion in a specific instance. “All mailboxes are blue. I am a mailbox.

Therefore I am blue.” Only works if the general rule is true. Showing a rule to be universally true is very

difficult. (100 blue mailboxes…..?) Showing a rule to be false is somewhat easier.

(1 green mailbox) Misuse: I am blue. Am I a mailbox?

Page 7: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

“The scientific method(s)” An attempt to formalize logical problem

solving and use it to understand the universe. Specific procedures may vary in practice. Has evolved considerably over time. Depends on certain epistemological

assumptions. Relies on experiments to gather empirical

data. Data supports or refutes hypotheses.

Page 8: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Epistemology (how we know) Positivist: “the truth is out there” Constructivist: “it depends on your point of

view” Post-positivist compromise: “Let’s assume the

theory is true until new empiric evidence suggests otherwise.”

Post-positivism helps self-correcting nature of scientific knowledge.

Post-positivism helps avoid dogma.

Page 9: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Hegemony There has always been a link between

science and politics, partly because of the link between epistemology (= how we know what we know) and hegemony (who has the power or authority to tell us what to believe and why).

E.g. struggles of Galileo.

Page 10: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?
Page 11: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

A good theory….. is makes testable predictions. resists falsification. is fruitful (suggests new hypotheses and new

connections or modifications for other theories).

contributes to human understanding and accumulation of knowledge.

Explains the underlying causes of phenomena.

Page 12: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

A good experiment….. controls independent variables and

tests the effect of changing a single dependant variable.

is repeatable and verifiable by others. Yields objective data, preferably

measured using instruments that minimize bias.

Page 13: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

“Scientific Law” Merely a description of something that always

happens, or of an observable mathematical relationship between variables that define phenomena. NOT an explanation for the phenomenon.

NOT as scientifically useful as a theory because it doesn’t attempt to explain anything.

Page 14: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

E.g. Charles’s law Charles's law: an observable relationship

between volume and temperature of a gas at constant pressure. V ÷ T = k

Molecular theory of the kinetic motion of gasses helps to explain this observation.

Page 15: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Scientific evidence. There are different types of evidence but only

certain kinds of empiric evidence are acceptable for scientific study.

Physical evidence of direct observation. Data from measuring devices. Other physical evidence of action and

reaction.

Page 16: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Not admissible in science: Eyewitness accounts. Anecdotes. Anything presented as absolute truth or not

open to further question. Anything that cannot be falsified by

experiment. Arguments based only on analogy. In practice, any data not published in a peer

review journal.

Page 17: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Contributors to the development of scientific thought: Aristotle (384-322BC)

observation, logic, deduction, naturalism Francis Bacon (1561-1626)

induction, empiricism David Hume (1711-1776)

induction and deduction Karl Popper (1902 - 1994)

falsifiability and pseudoscience Thomas Kuhn (1922 - 1996)

revolutions, paradigms, assimilation, accommodation

Page 18: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Humans are not natural scientists Faulty brain algorithms. Pareidolia and related adaptations. Tendency to use analogy, authority,

tradition, projection, anthropomorphism, instinct and other unscientific problem solving approaches.

We are dumb and lazy.

Page 19: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?
Page 20: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?
Page 21: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Ilove

Paris in the the spring time

Page 22: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Ilove

Paris in the the spring time

Page 23: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

Science Vs. technology Originally, technology was simply the use of any extra-

human materials to facilitate the life processes.

More recently, technology has come to mean the purposeful application of scientific principles and concepts to the construction of tools or ideas that help us modify our environment, solve practical problems or create pleasing artifacts.

Uses scientific method to some extent but technology solutions do not necessarily seek or suggest a full explanative theory.

Page 24: How do you know who I am ? Observations Construct a hypothesis Make predictions Test predictions? Devise an experiment? Can you be sure of your conclusions?

I think we need a break

Nothing about plants yet, I know. Please be patient.