Explicitness of Declarative Chunks

[Troy Kelley]

Jerry,

First, it is good to see someone posting to the ACT-R list.  I think you
might want to look at the literature and see if any there are any
experiments which look at just what people are aware of as explicit
knowledge and what they are not aware of.  This seems to be a pretty good
question for a few experiments because, off the top of my head, I don't
think many people have looked at what "explicit knowledge" constitutes and
what it excludes.  There is some evidence, from knowledge elicitation while
developing expert systems, that experts are not completely aware of their
knowledge, but I don't think anyone has really looked at this in any great
detail, i.e. *exactly what* are they not aware of, and why they not aware
of some things, but aware of other bits of their knowledge.  Theoretically,
to carry this a step further, I have some trouble with the notion that
people are completely unaware of procedural knowledge.  Sure it is
difficult to explain how to ride a bike, but that is because it is a motor
skill, and motor skills might not translate into words as easily as
something more cognitive, like playing chess for example.  I think if you
force people to think about what they know, more and more of the knowlege
comes out.  I am not sure if the simple fact that some things are difficult
to talk about, and difficult to quantify, perhaps because someone has never
had to talk about some aspect of their expertise before, that this
necessarily means that this knowledge is somehow unavailable or not
explicit.

These are interesting questions though, and a good area for research.

Troy Kelley
Army Research Laboratory






Jerry.Ball at williams.af.mil on 12/13/2001 02:59:20 PM





To:    act-r-users/@andrew.cmu.edu
cc:
Subject:    Explicitness of Declarative Chunks


It has been suggested that declarative chunks are explicit in that humans
are consciously aware of the contents of declarative chunks and can reflect
on their content.  However, it is not clear to me that the "type" of a
declarative chunk is something that can necessarily be reflected on. Thus,
if a human has a declarative chunk type  "ISA noun", it is not necessarily
the case that the human can reflect on that type. Humans may know that
words
belong to various categories without explicitly being able to reflect on
what those categories are. If, on the other hand, the Part of Speech of a
word is encoded in a slot with the type of the declarative chunk being
something like "ISA word", then the same argument holds for the slot
containing the POS.

For example, given

(man isa noun
   word man)

or

 (man isa word
     word-form "man"
     word-root man
     word-type noun)

Although the type "noun" is encoded in the declarative chunks, knowledge of
the type "noun" remains implicit.

Jerry