Presentation on theme: "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?"— Presentation transcript:
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?
How do you solve other problems? Why wont this stupid lamp work? Observations Hypothesis Experiment Empiric evidence Does bulb work? Rational formation of a theory Regression to other problem solving strategies.
A hypothesis is…. a best guess based on available observations. highly tentative and falsifiable. formed using creativity and imagination. formed using inductive logic.
Inductive logic Form a general rule based on specific observed instances. Oh look! A blue mailbox. Perhaps all mailboxes are blue?
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.
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?
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.
Epistemology (how we know) Positivist: the truth is out there Constructivist: it depends on your point of view Post-positivist compromise: Lets 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.
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.Galileo
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.
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.
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 doesnt attempt to explain anything.
E.g. Charless 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.
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.
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.
Contributors to the development of scientific thought: Aristotle (384-322BC) observation, logic, deduction, naturalism Aristotle Francis Bacon (1561-1626) induction, empiricism Francis Bacon David Hume (1711-1776) induction and deduction David Hume Karl Popper (1902 - 1994) falsifiability and pseudoscience Karl Popper Thomas Kuhn (1922 - 1996) revolutions, paradigms, assimilation, accommodation Thomas Kuhn
Humans are not natural scientists Faulty brain algorithms. Pareidolia and related adaptations. Pareidolia Tendency to use analogy, authority, tradition, projection, anthropomorphism, instinct and other unscientific problem solving approaches. We are dumb and lazy.
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.
I think we need a break Nothing about plants yet, I know. Please be patient.