[unrev-II] Document as "View" ==> True KR

From: Eric Armstrong (eric.armstrong@eng.sun.com)
Date: Sat Feb 12 2000 - 18:32:38 PST


From: Eric Armstrong <eric.armstrong@eng.sun.com>

Driving home from the colloquium the other night, I began thinking
about how an integrated document/email system would be used.
In particular, it occurred to me that perhaps my thinking had been
too limited by my experience with what we traditionally think of as
a "document".

Taking the software design process as a familiar example, let's
assume that we are using the document/email system proposed
earlier. We start with a functional specification, and carry on lots
of email interactions about aspects of that document. We go
through several iterations, and produced a completed specification
that we are happy with. So far, so good. But what happens next?

The next step in the development process is to construct a design
document. But now, we're starting from scratch! We can still make
use of the information adduced during the functional specification
process, but we have to laboriously find all the information nodes
that are applicable, and either integrate them into the new document
or make links. True, the process is easier than it would have been
in the past, but we are still doing a ton of manual labor that should
be avoidable.

What we would like, instead, is to capture design notes for each
part of the specification, as we think of them. When we look at the
"functional specification", we wouldn't see them. But authoring the
design document can start with a request to the system that says,
in effect: "Give me all the design notes that correspond to this
version of the specification".

Implication #1: Document as "Labeled View"
----------------------------------------------------------------
At this point, it occurred to me that maybe a "document" isn't (or
shouldn't be) an isolated entity, but rather a "labeled view" on a
nexus of information nodes.

In this formulation, the collection of email messages and document
segments forms a nexus of notes, thoughts, and ideas. Each node
exists as independent unit. The "hierarchy" is created by organizing
them into a document.

Perhaps that occurs by "tagging" the nodes to identify them as belonging
to, for example, "Functional Specification version 2.0", or "Design
Document, version 0.0". The label on the nodes might be what constitutes
a "document".

Or perhaps the label is a mechanism that retrieves information for
parts of a document. Once retrieved they might then be organized into
the design document. Perhaps they would be used as originally written,
or perhaps referenced (linked) in a new formulation. However it works,
it would create a natural starting point for the new document that
brought to light all of the thinking that was originally directed
towards it.

Implication #2: Database, not Flat Files
---------------------------------------------------------
Before I get to the serious implications for human thinking, I'm going
to pause long enough to make a low level observation: When we start
talking about storing every information node as an individual unit so
it can be tagged and used in multiple ways, the idea of using a plain
text filing system rapidly loses its appeal!

For such a system, a database clearly seems like the right approach.
XML then becomes the email/interchange mechanism, by which we
communicate ideas to one another. It should also be possible to
export the contents of the database as XML, for backup, archiving,
filtering, and transfer to new and better databases that come along.

Ok. That's done. Now for the important stuff...

Implication #3: Augmented Memory
----------------------------------------------------
The greatest initial appeal for such a system is that it _dovetails
nicely
with the way we think_. When we are thinking about how the system
functions, design ideas pop up. Code fragments may pop into our head,
as well.

A system of this kind makes it possible to capture those ideas as they
occur, in such a way that they do not interfere with the flow of the
original document -- the functional specification.

Most importantly, if the system operates as it should, none of those
ideas
are lost! They all come surging back when the designing starts, so that
none is overlooked.

At this point, the system has begun to carry out important functions of
a knowledge repository, by
  a) ensuring that ideas and information are not lost, and
  b) making them available when they are needed

Implication #4: Augmented Reasoning
-------------------------------------------------------
The system has also made an important step towards augmented
reasoning, however. What the system is allowing us to do is to
record and track *implications*.

Thinking of implications brings up the topic of logic. All you need
for a "logic" system is 4 operations: implication, and, or, and not.
When we record a design note, we are saying that functional
requirement "A'" implies design consideration "B".

Note that a "document" is a view of the system that instantiates
the "and" operation. (For this system, we need feature 1 and feature
2 and feature 3...)

IBIS/GIBIS-style investigations on the other hand, implement the
"or" operation. (For this question, we have 3 alternatives...)

If the system can integrate domain-exploration (IBIS-style
conversation) with domain-proposal (documents), it then begins
to support the reasoning process.

Again, this mechanism mirrors the way we think! When we look
at how the system will function, it is natural to explore design
alternatives. We may reject a function because the design is
impossible! And that is a fair thing to do. Even more important,
however, is recording the thinking that went into the decision so
that it can be easily reversed at a later stage, when new technology
is discovered.

Negation is the last important part of the logical process. In a
design effort, though, simple negation (proposition "A" is not true)
is the least important kind. The kind of negation that occurs a lot
in design discussion is "compound" negation, like this:
   (F1 & F2) ==> !(D1 & D2) ==> !D1 + !D2 =?=> !F1 + !F2

Here, a feature (F1) implies a design idea (D1). The statement above
says that the required features imply incompatible designs. (Either D1
or D2 can't be.) That means one of the design ideas has to be dropped.
In consequence, unless some compatible design can be found, one of
the features must be dropped.

This is fairly complex reasoning, but it is typical of the design
process. As someone said earlier, getting the specification "right"
is the key to a successful project, but note that getting it "right"
involves deep reasoning about the implementation feasibility of
the system, as well as its user-oriented goals.

For example, previously I had argued that the system's documents
should be stored in plain text files, because of the advantages that
attend that strategy. However, keeping thousands of information
nodes as individual files is clearly onerous, so that design idea
is contradicted by the these functional requirements.

When we record implications, then, we need the ability to
explicitly specify "and" and "or" relationships. We need to be
able to say that F1 ==> (D1 & D2 & D3) as well as the ability
to capture alternatives: (D1 & D2 & D3) + (D4 & D5).

In other words, my document (and this message) should not exist
as a single indivisible whole, but rather as a concatenation ("and")
of individual suggestions which can be organized, rearranged,
responded to, and have implications drawn, one at time.
 
Capturing implications and making it easy to find them assists the
human reasoning process. A system that does that will make it
easier for us to carry on intelligent design conversations and
discover inherent contradictions earlier in the process.

[Note: This analysis begs the intriguing question: What is the
best way integrate, display, and use both "and" and "or" lists
in a hierarchy?]

Implication #5: Automated Reasoning?
--------------------------------------------------------
At some point, it may be possible to begin automating the
reasoning process -- or least parts of it. The dream for such
a system would be the ability to ask "how can we do this"
and get back a collection of design ideas captured from
previous designs. (The "design patterns" concept falls into
place, here.)

The system might present the patterns, with the pros and cons
for each, with the most typical pattern first. That begins to turn
the design process into more of a "review and select" operation.

In addition, asking the system to "enumerate all the design
ideas that correspond to this version of the functional specification"
is in essence asking it to complete the implication statement:
   (F1 & F9 & F12 &...) ==> ??

In a sense, then, the system has made a first step towards
automated reasoning. Harder operations like identifying
contradictions and synthesizing a unified view will probably
remain human operations for a very long time, but they might
one day be automatable, as well.

Implication #6: Augmented Synthesis
------------------------------------------------------
All that has been said so far applies to deductive logic. To be
complete, the system should also augment the task of inductive
thinking, or "synthesis".

In essence, "synthesis" consists of building on other ideas:
combining them, abstracting them in some way, or incorporating
them into a larger whole. The augmentation for that process
lies in the ability to:
  a) Enumerate related nodes (e.g. "design ideas")
  b) Create new nodes that either link to the originals or
      create new segments that incorporate them

For example, when two classes are implied by design, you may
derive a superclass and add that to the design. The system
path would look something like this:
  F1 ==> D1 ==> C1 \
                                 +---S1
  F2 ==> D2 ==> C2 /

Here, each feature led to a design that implied a particular class.
The synthesis into a superclass (S1) was augmented by the
availability of the class definitions and the ability to reuse that
information.

At some point, too, F2 might be removed from the list of
requirements. Ideally, the system would proactively flag the
implications as invalid for that version of the system, making the
superclass unnecessary.

At a minimum, though, it would be possible to retroactively answer
the question, "Why does S1 exist?", by exploring the links to C1
and C2 and finding that
  a) One of them does not in fact exist, and
  b) It was planned for a while, but depended for its existence on
      a feature that was later dropped.

Implication #7: Standardized Tags
-------------------------------------------------
(Back to a more mundane topic to finish up this post.)
To be able to pull out all the design notes for a system, they must all
be tagged in some standard way. That's an area that needs work.

Perhaps specialized domains like software development could have a
predefined set of tags for the major documents and processes that go
on during software development.

As helpful as that is for processes we (believe) we understand, though,
it's not much use for "wicked" problems, where understanding only
emerges as we explore the problem. For such cases, perhaps a
generalized "derivative" or "implication" tag is more appropriate.

One might then ask the system to enumerate all the derivative ideas,
or implied ideas, in order to construct the next document. It might
be, then, that design nodes are a "first order derivative" from
specification
nodes, while code is a "2nd order derivative". Mathematical people
will probably like that. Most everyone else would probably prefer
labeled tags.

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