Science, Theories, and Models
Abstracting away from details, describing the phemonenon
in terms of a small number of variables
- What is science good for anyway?
- If we have a better understanding of how things work,
we can build things or manipulate
the world in such a way that we improve the quality of life.
- We're curious creatures; we want to know what makes things work.
- Phenomena, behaviors
- Kinds of phenomena
- How two or more variables correlate with each other
- Voting behavior: position on abortion, position on death penalty,
position on amount of defense spending, party usually voting for
- How one variable causes changes in another
- Television violence and violent behavior
- Red wine drunk and lessened risk of heart disease
- How the system changes over time
- The time course of a disease
- The behavior of an object which is thrown against the ground
- Physical, biological, cognitive, social phenomena; different
- Why distinguish the levels (why not all physical)?
Different levels require different elements
for description or explanation.
Imagine describing or explaining the religious practices of some
ethnic group (a phenomenon at the social level)
in terms of the molecules of their bodies and
the objects around them (elements at the physical level).
- Qualitative and quantitative phenonema
- Qualitative: children not exposed to language before puberty
fail to learn grammar.
Children learn an average of 9 words a day between the ages
of 5 and 9.
- Phenomena of interest in this class
- The way in which animals walk
- The way in which people identify the meter in a simple
rhythmic pattern or a piece of music
- The way in which people produce the rhythm in a
simple pattern or a piece of music
- The way in which people learn to identify or
produce rhythmic patterns
- The nature of the rhythmic patterns in language: how they are
identified, produced, learned
Focusing in on subproblems
- In describing and explaining the perception of musical meter,
consider the effect of tempo, beat intensity, etc., but not
the temperature of the room or the mood of the subject
Description (what) and explanation (why)
- Appreciating a piece of music (too large to study)
vs. finding the meter in a piece
- Listening to a piece of music (too large)
vs. listening to a simple
Comparing and evaluating explanations (theories)
- Description: Democratic political systems oscillate between periods of
more liberal and more conservative periods.
- Explanation: Party systems make one sort of view clearly
dominant at a given
time. People tend to blame the current government for problems, which
always exist, so whichever party is in power will not stay there long.
- But there is not always agreement on what counts as explanation.
Predictions from a model, hypotheses, and experiments
Computer models, computer programs,
algorithms, and experiments with the model
- Multiple explanations (theories) for the same phenomenon
- Theory of Gravitation vs. a theory by which all objects are
attracted to the earth
- Theory of Evolution vs. Creationism
- Handling the data: the theory must account for the facts
- Single explanations of multiple phenomena
- Gravitation: objects falling to earth, objects floating
on the surface of water, planetary orbits
- Theory of memory for music and language vs. one that
works just for music
- Theory of animal gaits that handles the gaits of all animals,
not just those of 4-legged animals
- Independent motivation
- A theory of meter perception which makes use of a short-term
memory, which is required anyway for psychological theories
outside of meter. The short-term memory idea has independent motivation.
- A theory of gaits which posits oscillators in the brain.
We already have reason to believe that there are oscillators
in the brain.
- Emergent behavior: a theory explains a higher-level behavior
in terms of a lower-level one; the higher-level behavior "emerges"
from the interaction of simple processes at the lower level
- Termite nest building: The termites seem to require a central
control and details instructions for each of their roles, but the
behavior is explainable in terms of the interaction of very simple
behaviors of individual termites.
- Simplicity, "elegance": Prefer theories that involve
fewer variables and few mechanisms.
- Comprehensibility: Prefer theories which are easier
for people to understand.
- Complete instructions for how to build a cockroach
at the level of individual cells would not be a very
good theory of the cockroach.