01-09-14
Kognition interaktion design
Vårterminen
2014
ISP vs WSP
It is not exaggerating much to say that
there are no WSPs, only ISPs that have
been formalized for problem solvers .
Simon, 1973, 186
Teorem-bevisandet - WSP?
•  (4) Any knowledge that the problem solver
can aquire about the problem can be
represented in one or more problem spaces
•  Prohibits use of knowledge available in
another problem space that may facilitate the
proof: It follows that … problems of
discovering proofs in formal logic are not, for
all problem solvers, well structured
•  Practical solvability not incompleteness etc.
”…definiteness of problem structure is
largely an illusion that arises when we
systematically confound the idealized
problem that is presented to an idealized
(and unlimitedly powerful) problem solver
with the actual problem that is to be
attacked by a problem solver with limited
(even if large) computational capacities”. Simon, 1973, 186
ISP vs WSP
We may ask instead how problem
solvers of familiar kinds can go to work
on problems that are, in important
respects, ill strucured … perhaps we
have exaggerated the essentiality of
definte structure for the applicability and
efficacy of these techniques.
Simon, 1973, 187
Schack – ett WSP?
•  Skilj mellan att kunna beräkna något i
teorin och i praktiken
•  Playing a game off chess – viewing
this activity as solving a single problem
– involves continually redefining what
the problem is (Simon, 1973, 186)
1
01-09-14
Varför?
”The move in the real game … has real
consequences that cannot be undone,
and that are frequently different from the
consequences that were anticipated”.
En blick framåt: Murtaugh
”In general, the problems presented to
problem solvers by the world are best
regarded as ISPs. They become WSPs
only in the process of being prepared for
the problem solvers”.
En blick framåt:
Adult Math Project
“...there is one important feature of grocery
shopping behavior that cannot be simulated
easily. In the supermarket people generate
their own problems as well as solve them,
whereas in the laboratory, problems are
formulated by the researcher” (Murtaugh,
1985, s. 186).
•  American Beauty nudlar eller Perfection
nudlar?
•  Små paket: Perfection billigast
This is really the too-large economy bag. I
don't know if I, probably take me about six
months to use this one. And I just, I don't
have the storage room for that kind of
stuff. I guess if I rearranged my
cupboards, maybe I could, but it's a
hassle... I don’t know, I just never bought
that huge size like that. I never checked
the price though on it. But being American
Beauty, it probably costs more even in
that large size. (Lave, 1984: 85-86)
Oh there is a big savings. Hmmm, I might
think about that next time, figure out
where I can keep it. I actually try to look
for better prices. I used – I guess I used
to, and I was such in the habit of it that
some of the products I'm buying now are
leftovers from when I was cutting costs.
And I usually look. If they have something
on sale, you know, a larger package of
macaroni or spaghetti or something, I’ll
buy it. (Lave, 1984: 86)
2
01-09-14
The whole design, then, begins to acquire
structure by being decomposed into various
problems of component design, and by
evoking, as the design progresses, all kinds
of requirements to be applied in testing the
design of its components. During any given
short period of time, the architect will find
himself working on a problem which,
perhaps beginning in an ill strucutred state,
soon converts itself through evocation from
memory into a well structured problem. Simon, 1973, 190
Coordinating subtasks
Much of the coordination of the various
well structured design subtasks is implicit
– built into the organization of the whole
process. To the extent that this is so, the
local design activities are guaranteed to
mesh into a reasonable over-all structure. Simon, 1973, 191
Varför den här strukturen?
•  ”The answer revolves around the
basically serial character of the problem
solving system”
•  ”… no need for … initial definition of the
problem space and task structure. All of
the necessary definitory information is
potentially available, but distributed
through long term memory”.
The robot … will continually be confronted with
new information from the environment: features
… that are omitted from or distorted in
its internal representation… and changes
… that are different from the changes
that were predicted …. But this
external information can be used
by the robot in the exactly the way
that information evoked from the
long term memory was used by the
architect”.
The present view of the boundary between
WSP and ISPs derives from our insistence
that notions of computability in principle be
replaced by notions of practical
computability in the definition of WSP Simon, 1973, 174
3
01-09-14
Håller ni med?
“Conversely it suggests that there may be
nothing other than the size of the knowledge
base to distinguish ISPs from WSPs, and
that general problem-solving mechanisms
that have shown themselves to be effacious
for handling large albeit apparently wellstructured domains should be extendable to
ill-structured domains without any need for
introducing qualitatively new components”.
Simon, 1973, p. 194
Kirsh om handlingar (action)
K&M:s syn på den klassiska
modellen
“The processing model … is a significant
departure from classical theories of action.
Its chief novelty lies in allowing individual
functional units inside the agent to be in
closed-loop interaction with the outside
world”.
(p. 542)
K&M:s syn på den klassiska
modellen
The point of planning is to discover a series of
transformations that can serve as a path from
initial to goal state. The metric of goodness, which
planners rely on, may be the distance, time, or
energy required in getting to the goal, an
approximation of these, or some measure of the
riskiness of the paths. In each case, a plan is a
sequence of pragmatic actions justified with
respect to its adequacy along one or another of
these physical metrics.
4
01-09-14
Grunden för kritiken
•  ”If one’s theory of the agent assumes
that thinking precedes action, and that,
at the best, action can lead one to reevaluate one’s conclusions, then action
can never be undertaken in order to
alter the way cognition proceeds (sid.
526).
Jämför med:
Jämför The Star user interface
A well designed system makes everything
relevant to a task visible on the screen. …
When everything being dealt with in a
computer system is visible, the display
screen relieves the load on the short-term
memory by acting as a sort of visual
cache Smith et al, 1982
When everything being dealt with in a
computer system is visible, the display
screen relieves the load on the short term
memory by acting as a sort of visual
cache . Thinking becomes easier and
more productive. A well-designed
computer program can actually improve
the quality of your thinking.
Pragmatiska och epistemiska
handlingar
Epistemisk handling
…we use the term epistemic action to designate a
physical action whose primary function is to
improve cognition by; 1) unearth new information
very early in the game, 2) save mental rotation
effort, 3) facilitate retrieval of zoids from memory,
4) make it easier to identify a zoid’s type, 5)
simplify the process of matching zoid and contour
K&M, 1995, 514
5
01-09-14
Hur kan K&M visa att det inte
bara finns pragmatiska
handlingar?
O-pragmatiska rotationer
Antal rotationer
If players actually wait until they have
formulated a plan before they act, the
number of rotations should average to half
the number of rotations that can be
performed on the zoid before an orientation
repeats.
K&M 1994, 523
Identifikation
1) Identification: zoids can be physically
rotated 90º in as few as 100 ms, whereas we
estimate that it takes in the neighborhood of
800 to 1200 ms to mentally rotate a zoid
90º, based on pilot data
K&M, 1994, 530
O-pragmatiska rotationer
Placering
2) Placement: In about 1% of the cases wehn
a player drops a zoid, the act of dropping is
preceded by a behavioral routine of
translating the zoid to the wall and then
back again
K&M, 1994, 539
6
01-09-14
Vad bidrar K&M med?
... we should now confront a task and ask not only,
”How does the agent think about this task, for
example, categorize elements in it, construct a
problem space representation for it?” but also,
”What actions can an agent perform that will make
the task more manageable, easier to compute?”
Kirsh & Maglio 1994 (p. 545)
Vad bidrar K&M med?
Consequently, we expect that a well-adapted agent
ought to know how to strike a balance between
internal and external computation. It ought to
achieve an appropriate level of cooperation
between internal organizing processes and
external organizing processes so that in the long
run, less work is performed.
Kirsh & Maglio 1994 (p. 545)
Diskutera!
Hur olika är K&M och Simon?
The experimenter varies the external stimuli with
the hope of discovering the subject s internal
organizing processes … it reflects a bias that the
type of environmental structure relevant to
problem solving, planning, and choice, as well as
to recall and recognition, occurs primarily inside
the agent. K&M, 1995, 545 Representation vs. offloading
Jämför m. K&M (och
Hutchins)
Simon about Sir Oswyn and battleships:
The long-term memory here is literally a
distributed memory, divided among the
various groups of experts who are involved
at one or another stage of the design
process (Simon, 1973, 194)
7