Making Theoretical Progress Flashcards
What is Deductive reasoning?
‘top down’ approach, more narrow, concerned with hypothesis testing
What is Inductive reasoning?
‘bottom up’ approach, more open-ended, more exploratory
What is the The Vienna Circle?
Logical positivism (observation – induction – verification = demarcation of science)
Problems with Verificationism
- Induction problem
- What about unobservable facts?
- Our observations may be wrong!
- Our observations are not objective
Who was Karl Popper (1902-1994)?
- Austrian-born scholar
- Member of the Vienna Circle
- Professor at the London School of Economics
- Popper’s initial interest was psychology
What did Popper believe?
- Falsification instead of verification
- Science constantly questions its explanations
- Physics: Progress through finding weaknesses of theories
- Psychoanalysis: Progress through finding corroborating evidence
What is Falsification?
disproving a hypothesis or theory
What is Falsifiability?
criterion for demarcating science form nonscience
Hypothetico-Deductive Method
-Observation – interpretation – hypothesis (falsifiable) – test – (loops around again)
What is Scientific Progress?
Inductive & deductive reasoning
What did Popper believe about a hypothesis?
Hypothesis should be directed at a possible falsification
What are Degrees of falsification?
- The more falsifiable a theory, the higher its scientific status
- Example: wine sours because of organisms. Wine sours because of bacteria coming from the air
- The more specific a statement, the more prone to falsification, the higher the scientific status
What is Theory of General Relativity?
- Describes relationships between space time and mass
- Prediction: large masses bend space-time so it appears light is bent
What are the criteria for choosing theories?
- Scope
- Precision
- Parsimony
- Increasing falsifiability
- Fruitfulness
What is Science ?
process of trial and error
What is scope?
- A good theory makes wide-ranging claims about the world
- Example: Mars moves in an ellipse around the sun. All planets move in an ellipse around the sun.
What is precision?
- The more precise a theory the more falsifiable it is.
- Example: Planets move in ellipses around the sun. Planets move in closed loops around the sun.
- Operational definition –describes exactly what the variables are and how they will be measured.
What is Parsimony?
- Among competing theories, the one that makes the fewest assumptions should be favoured. -Occam’s Razor →simple theories are preferred
- Example: Event: It is raining, and I saw a bright flash through my curtains. Explanation A: There was lightning. Explanation B: Some is trying to take pictures of me
Is it good to increase falsifiability?
- The more falsifiable a theory the better.
- Theories should become more and more falsifiable: More content and more informative
- A replacement theory should be more falsifiable than that which it replaced.
- Example: All bread nourishes. Bread, with the exception of that particular batch of bread produced in the village in question, nourishes. All bread nourishes except bread made from wheat contaminated from a fungus
What is fruitfulness?
- Has the theory led to new empirical discoveries?
- Does the theory lead to scientific progress?
- Falsifying theories and offering more precise and falsifiable replacements leads to new discoveries
- Example: Theory: Bats have weak eyes, but they are sufficient to see. Test: Blindfold bats and release them in room. Theory: Bats use their ears to avoid obstacles in the dark. Test: Plug the ears before releasing them. Theory: The bat uses echoes of its own squeaks rebounding. Test: Gag before releasing them
What is Confirmation bias?
tendency to seek confirming evidence
What are the problems with falsifiability?
Do not give up too easily: Newton’s laws of physics, the motion of Uranus, and the discovery of Neptune
What are ad hoc modifications?
- Ad hoc modification = changes to a theory that makes the theory less falsifiable
- What are allowable and unallowable modifications?
- Example: Fingerprint analysis
Who was Thomas Kuhn (1922-1996)?
- American physicist
- The structure of scientific revolutions
- Science is social activity
- Scientific Paradigm -set of common views of what the discipline is about and how problems should be investigated
A paradigm determines…?
- What is to be observed and scrutinized
- What kinds of questions should be asked
- How the questions are to be structured
- How the results of scientific investigations should be interpreted
- How an experiment is to be conducted
- What equipment will be used
Structure of scientific revolution
Pre-science, normal science and revolution
What is Pre-science?
Unorganized facts, observations and models to explain small scale phenomena
What is normal science?
Researchers share paradigms. Attempts made to falsify the theory. Modifications can be made.
What is revolution?
Confidence in paradigm decreases, crisis, scientific revolution, and paradigm shift
Implications of Kuhn’s theory
- Paradigms are ever changing
- Revolution = progress?
- Knowledge = relative and time dependent
- Scientists engage in “puzzle-solving”
Kuhn vs Popper
-Kuhn
-Normal science = important
-Scientists should criticise occasionally
-Hypercritical scientists don’t get any work done!
-Conformity and focused puzzle-solving are essential
-Popper
-Normal science does exist but ≠ good science
-Scientific approach = critical attitude
-Criticism and non-conformity are essential
Problems with Kuhns account
- Too vague
- What is a severe trouble spot?
- How long should scientists stick with a theory in the face of trouble spots?
- Why should working with a theory for a long time improve the chance of identifying limitations?
