Ted Neward, "Computational Philosopher"
this means I like to wrestle with really interesting/hard questions that often have no answers, and even more often create more questions
the actualities of artificial intelligence
interview processes
how to manage developers
I look for answers in the Liberal Arts
history, psychology, economics and particularly philosophy
Programming is an extremely ephemeral activity
we cannot see it--only its side-effects
we cannot touch it--only the machine within which it is contained
and sometimes not even then
we cannot observe it directly
in fact, we require more software to diagnose and correct it
Given how much we rely on our understand of abstractions...
Psychology
... understand where those abstractions live
... understand how those abstractions come to exist
... understand the limitations of those abstractions
Philosophy
... learn what to question and why
... come to grips with what we know and don't know
... begin where all science began
What is philosophy?
"love of wisdom" (Ancient Greek)
the fundamental root of all thinking
the basis of all science
"science in one hand, and religion in the other"
the central question that philosophy seeks to answer
Ironically, most of us are (already) philosophers
what should we do?
what is there?
how do we know? if we don't know, how should we set about finding out?
Major branches of philosophy
Metaphysics
examining what exists, the difference between mind and matter, and so on
Epistemology
how do we know a thing? how do we acquire knowledge? what is the nature of knowledge?
Logic
Aristotelian syllogisms up through mathematical and symbolic logic
Moral philosophy and ethics
what is right? what is evil? what is virtue? what does it mean to live a good life?
Political philosophy
what are the "unassailable human rights"? what is the relationship between government and the governed?
Aesthetics
what is beauty? what is art?
Roger Scruton ("A Short History of Philosophy")
two distinguishing characteristics of philosophical thought
abstraction
concern for truth
"Problems of philosophy and the systems of design to solve them are populated in terms which tend to refer not to the realm of actuality, but to the realms of possibility and necessity: to what might be and what must be, rather than what is"
Philosophy is characterized by several things
students are encouraged not to accept the conclusions of their teachers, but to discuss, argue and disbelieve
arguments are rooted in logic and reason, not faith or belief
Most science begins as philosophy
"It has often been remarked that when an area of inquiry begins to find its feet as a discipline, with clearly agreed methods and a clearly agreed body of knowledge, fairly soon it separates off from what has up to then been known as philosophy and goes its own way."
such as....
physics
chemistry
astronomy
psychology
some continue to maintain tight relationships
When do individual grains of sand become a heap?
When do individual grains of sand become a heap?
More importantly, why does this paradox take place?
The god Apollo and a turtle are going to race
The god Apollo and a turtle are going to race
Apollo gives the turtle a huge head start
The god Apollo and a turtle are going to race
Apollo gives the turtle a huge head start
But if Apollo makes up half the distance between him and the turtle every second...
The god Apollo and a turtle ae going to race
Apollo gives the turtle a huge head start
But if Apollo makes up half the distance between him and the turtle every second...
... he can never catch the turtle!
An arrow is loosed from a bow to fly through the air
An arrow is loosed from a bow to fly through the air
But in any single moment in time, the arrow is not moving
An arrow is loosed from a bow to fly through the air
But in any single moment in time, the arrow is not moving
... therefore the arrow is not really moving at all!
Xenophanes of Colophon (570 - 475? BC)
exiled to Southern Italy
criticized Homerian concept of anthropomorphized gods
the first to actually engage in evidence-based argument
his thoughts centered around the nature of knowledge itself
Gods are a reflection of the culture that worships them
'the Ethiopians make their gods black and snub-nosed;
'the Thracians say theirs have blue eyes and red hair.
'if oxen and horses had hands and could paint,
'oxen would paint their gods as oxen, and horses as horses.'
Natural nature of the universe: Mud
he had noticed fossil remains in the earth
guessed that perhaps the world dried up
thus returning to its original muddy state
trapping and preserving the creatures as it did
True belief
when we say we "know" something, that knowledge is actually only a "true belief"
a hypothesis good enough for us to work from
he maintained that a "truth of reality" did exist, but will always be beyond our human understanding
the best we can do is refine our hypotheses continually to get nearer to it
leads to a methodology of falsification
picked up in modern times by Karl Popper
Psychology is...
"the scientific study of the human mind and its functions, especially those affecting behavior in a given context"
"the mental characteristics or attitude of a person or group"
Five main perspectives
Biological
the relationship of the body and the mind
Learning
long-lasting change in the way a person/animal behaves that is attributable experience
Cognitive
study of memory, perception, thought and other mental processes
Sociocultural
how social environment and cultural beliefs shape our lives
Psychodynamic
study of unconscious motives and desires
"Opposites attract""Spare the rod, spoil the child""Familiarity breeds contempt""There's safety in numbers"
These are popular sayings/platitudes
most people hold them to be self-evident
when, in fact, science repudiates all of the above
many of these "facts" come from the "pop psychology" world
Some popular psychological "facts"
"We only use 10% of our brain capacity"
"If we are angry, it's better to express the anger directly than hold it in"
"Most sexually-abused children grow up to become abusers themselves"
"People with schizophrenia have 'split' personalities"
"People tend to act strangely during a full moon"
All of these are verifiably false
In some cases, we are misled by supposed experts
"Dr Phil" likes to use the lie detector on his show
when in fact lie detectors are not nearly as accurate as assumed
popular authors will sometimes get the psychology wrong
we are forced to accept their claims on faith alone
or they will explain only parts of it
because they want to keep our attention
or their readers will only hold on to the simplest parts of it
because our memory is fallible and we seek patterns
In some cases, we believe we are the experts
or close enough, anyway--how hard can it really be?
"if I am smart enough to do (some complicated activity), I am smart enough to understand this other stuff"
it's what leads doctors to believe they are lawyers, and lawyers to believe they are rocket scientists, and so on
this is hubris
it is a difficult thing to overcome; it requires a constant self- or externally-imposed monitoring of our thoughts and actions
In some cases, the science is "close enough"
... but not perfect
example: 'ulcers are caused by body's reaction to stress'
no cure; "lower-stress lifestyle and a managed diet"
two Australian researchers (Barry Marshall, Robin Warren) discovered bacterium in the stomach
"not possible--nothing could survive human stomach acid"
meet "Helicobacter pylori": it does, in fact survive in the stomach
... and these ulcers can be treated by everyday antibiotics
... and they won a Nobel Prize for it
they weren't the first to "discover" it; it had been spotted by at least three separate teams of researchers a century earlier
In some cases, it contradicts our common sense
our brains are good at interpreting the world
our brains are terrible at interpreting our brains
Jacob Bronowski (1966) called this "reflexivity"
there is not yet any kind of "debugger" for the brain
though we may be getting closer....
Psychological Science vs "Common sense"
Talk show host Dennis Prager:
"There are two kinds of studies in the world: those that confirm our common sense, and those that are wrong"
"Use your common sense. Whenever you hear the words 'studies show'--outside of the natural sciences--and you find that these studies show the opposite of what common sense suggests, be very skeptical. I do not recall ever coming across a valid study that contravened common sense. (Prager, 2002, p 1)"
Malcolm Gladwell gets into this ("Blink")
And yet... science is "uncommon sense"
"Phrenology can determine your personality"
"X-Rays are harmless festival entertainment"
"Emotions originate from the heart"
"Women are less intelligent than men"
"The body is made up of four 'humours': blood, black bile, yellow bile and phlegm"
those last three were Aristotle's beliefs
And yet... science is "uncommon sense"
"Nothing could be more obvious than that the earth is stable and unmoving, and that we are the center of the universe. Modern Western science takes its beginning from a denial of this commonsense axiom ... Common sense, the foundation of everyday life, could no longer serve for the governance of world. (Borstin, 1983, p. 294)"
This doesn't mean all common sense is wrong
happy employees get more work done than unhappy ones
But it does mean that we need to treat common sense with skepticism
if "everybody knows", then maybe they're wrong
What real damage is there to believing in a few folk tales?
nobody ever died from believing in Greek myths, right?
Psychological myths can be harmful
jurors who believe memories are like videotape will vote to convict a defendant on the basis of confidently-held inaccurate eyewitness testimony
parents who believe punishing children is an effective means of changing long-term behavior will achieve the opposite
doctors who refuse to allow their authority to be questioned will continue to kill patients
Psychological myths can cause indirect damage
the belief that we are "rational actors" when we make economic decisions
people waste money on "subliminal self-help tapes"
we may make decisions based on inaccurate information (such as a political candidate's honesty or what they've said or not said
The acceptance of psychological myths can impede our critical thinking in other areas
our failure to distinguish myth from reality in one domain of scientific knowledge can easily spill over to a failure to distinguish fact from fiction in other areas (Carl Sagan)
as a consequence, we may find ourselves at the mercy of policy-makers who make unwise and/or dangerous decisions
"Knowledge is power; ignorance is powerlessness" (Sir Francis Bacon)
A mythbusting toolkit
these are ten common sources of error
compensate for them whenever used or seen
Ten sources of error
Word-of-Mouth ("urban myths")
Desire for Easy Answers and Quick Fixes
Selective Perception and Memory
Inferring Causation from Correlation
Post Hoc, Ergo Propter Hoc Reasoning
"after this, therefore because of this"
Ten sources of error
Exposure to a Biased Sample
Reasoning by Representativeness
beware of heuristics (mental shortcuts/rules of thumb)
Misleading Film and Media Portrayals
Exaggeration of a Kernel of Truth
Terminological Confusion
Literal visual and auditory stimuli is not the end of the story
rods and cones interpret colors of what we see
but images are easily "separated" into groups
the brain interprets images using a form of pattern recognition
Gestalt Psychology
a school of thought originating in Germany in the early 1900s
people organize visual information into patterns and forms
this explains many optical illusions, for example
Gestalt Principles
Figure and ground
"figure" is what stands out
"ground" is the backdrop in which the figure appears
Proximity
when objects lie close together, objects are perceived as a group
Closure
interpret familiar, incomplete forms as complete by filling in gaps
Gestalt Principles
Similarity
group similar objects together
then interpret the larger pattern
Continuity
interrupted lines/patterns are interpreted to be continuous w/gaps
Simplicity
perceives forms as simple, symmetrical figures rather than irregular ones
Depth Perception
in order to perceive distance, we use binocular and monocular cues
binocular: cues that require both eyes
monocular: cues that require only one eye
Binocular cues
Retinal disparity
the eyes lie a few inches apart
thus their retinas thus pick up slightly different images of objects
retinal disparity increases as the eyes get closer to an object
Convergence
the eyes must turn "inward" (towards each other) to look at an object close-up
the closer the object, the more muscle movement
thus, the more muscle movement, the closer the object is
Monocular cues
Interposition
when one object is blocking part of another, the blocked object appears further away
Motion parallax (relative motion)
when the viewer is moving, stationary objects appear to move in different directions/speeds depending on their location
the more distant the object, the slower it moves
the closer the object, the faster it moves
Relative size
people see objects that make a smaller image on the retina as farther away
Monocular cues
Relative clarity
objects that appear charp, clear and detailed are seen as closer than hazy objects
Texture gradient
smaller objects that are more thickly clustered appear farther away than objects that are spread out in space
Linear perspective
parallel lines that converge appear farther away
the more the lines converge, the greater the perceived distance
Light and shadow
patterns of light/shadow make objects appear three-D
Perceptual consistency
the ability to recognize than an object remains the same even when it produces different images on the retina
shape constancy
size constancy
brightness constancy
color constancy
location constancy
Perceptual set
the readiness to see objects in a particular way based on expectations, experiences, emotions, and assumptions
Selective attention
the ability to focus on some bits of sensory information and ignore others
this is what allows you to read these slides or watch this talk!
Context effects
peoples immediate surroundings create expectations that make them see in particular ways
What do we do with this? (Ask questions, of course!)
what makes good code? what is a good programmer?
how do we hire the best? how do we keep them?
does agile actually work? or was/is there something else actually at work?
what does our customer really want?