There is evidence for the importance in decision
making of higher-level executive, or metacognitive, processes
for verifying and improving the results of pattern recognition
(Cohen, Freeman, & Wolf, 1994). Such metacognitive processes,
once acquired, may also support more rapid explanation-based
learning of domain knowledge. The proposed research will investigate
an architecture for the connectionist learning of metacognitive
skills and the related learning of domain facts within a naval
tactical decision domain (Towne). The proposed design is a hybrid
which uses (1) a localist connectionist model to support rapid
recognitional domain reasoning, (2) a distributed connectionist
architecture for the learning of metacognitive behavior, and
(3) a symbolic subsystem for the control of inferencing that
mediates between the domain and metacognitive systems. We will
test implications of the design for three aspects of human learning:
learning metacognitive skills in the testbed task; improved
domain learning in the testbed task supported by metacognition;
and transfer of metacognitive skills to new domains.
The objectives of the research are: (a) to explore the feasibility
and benefits of a novel combination of symbolic, localist
connectionist, and distributed connectionist processing, that
captures the role of executive, higher-order skills and advanced
domain learning; (b) to expand theoretical and empirical understanding
of metacognitive skills; (c) to derive principles for the
design of decision aids and training that support the acquisition
and use of metacognitive skills; and (d) to produce a self-improving
Naval tactical system that can serve as the core for an adaptive
tactical decision aid or intelligent training system.
The proposed research will integrate and build on previous
technical work by the project team in a number of areas: (i)
a theory of human decision making, called the Recognition
/ Metacognition (R/M) framework, which combines recognition
with metacognitive processes that monitor and improve the
results of recognition; (ii) empirical research testing that
model and its training implications in the Naval tactical
decision making context (as part of an on-going project in
the TADMUS program); (iii) research on and implementation
of innovative connectionist adaptive critic architectures
for integrated reinforcement-driven adaptive behavior and
model learning; and (iv) development of a connectionist model
for rapid recognition-based domain reasoning (Shastri's Shruti
system).
Significance
The significance of this research lies in what
it can tell us about the structure and dynamics of human long-term
memory (LTM). We are exploring the interactions of reflexive,
inferential LTM, Shruti,
with semi-autonomic meta-cognitive processes. The key interaction
between these two systems is the adaptive direction of focused
attention within the reflexive memory in response to learned
metacognitive behaviors. There are inherent, and dynamic, limits
in the scope of LTM which may be brought to bear in interpreting
any evidence. Recency effects and learned attention shifting
behaviors are used to assemble such intermediate results into
composite assessments. The model suggests that the development
of executive attention functions may be necessary for, and integral
to, the development of LTM. In addition, and equally significant,
we are exploring ways in which an agent may evaluate the utility
of a situation estimate and utilize that situation estimate,
and a model of utility, to (reflexively) construct plans and
take actions. Agents using these mechanisms (attention shifting,
a model of utility, and a structured, inferential LTM) will
be able to operate a multiple levels of spatial and temporal
abstraction, resulting in a non-linear increase in planning
horizon.
The algorithms for reflexive inference are computationally
bounded by the length of the longest inference chain explored
(not the number of facts or rules the agent possesses, nor
the number of inferences drawn). When implemented on parallel
hardware, the agents will be capable of real-time interactions
with their environments. The reflexive system has an intended
decision cycle time of less than 500 milliseconds. The metacognitive
system integrates reflexive results and operates in longer
cycles as it examines and structures uncertainity by exploring
alternative interpretations of the evidence. The tradeoff
between further exploration and action is moderated by the
expected value of not-acting compared with the expected value
of continuing to explore (e.g., 'the Quick Test' gating function).
If borne out by future research, this work will have a profound
impact on how we model intelligent behavior and learning,
and on what we can hope to accomplish with such models. For
example, the present research points to a conceptually novel
architecture for model-based adaptive control in real-time
systems. An agent based on this research would not need to
'back-up' expectations of future rewards and would automatically
(reflexively) compute optimal policies as the model changes
in response to (a) discovery by the agent or (b) changes in
the dynamics of the environment. In contrast, the existing
methods 'crystallize' on a value function. If the model changes,
the value function must often undergo catastrophic re-learning
or remain markedly sub-optimal. Further research is needed
to (1) extend the implementation; (2) demonstrate these capabilities;
and (3) firmly map out the theoretical relationship between
the present work and (a) other models of human memory, and
(b) existing theory and proofs in model-based adaptive control.
Technology
Transfer
Transitions.
The hybrid system will be a self-improving artificial system
that can provide the basis for intelligent decision aids and
adaptive human-system interfaces. CTI staff have developed
and applied a concept of personalized and prescriptive design
to decision aids and adaptive information display, in which
aids adapt to the decision making strategies of individual
users, while at the same time guarding against potential errors.
The hybrid system can significantly advance the technology
of adaptive decision aiding in three ways. (a) It provides
a model of human decision making that can be matched with
user performance, in order to infer the user's decision making
strategy, to adapt the interface to that strategy, and to
diagnose potential problems. (b) It provides a self-improving
domain model (essentially, an expert model) to serve as the
basis for comparison with the inferred user model, for assessment
of the significance of observed discrepancies, and for displays
and prompts that mitigate potential errors in the user model.
(c) Metacognitive processes for critiquing and correcting
problems in the domain model are embodied in the hybrid system,
and provide a naturalistic basis for displays and prompts
that alert users to potential difficulties with their own
domain models and plans. The hybrid system, for example, will
already be equipped with processes to determine when time,
uncertainty, and costs of potential errors warrant a more
careful look at a conclusion or plan. Similarly, it will already
be equipped with mechanisms for detecting problems such as
incompleteness, conflict, or unreliability in a model or plan,
and with methods that can be used to address each type of
problem.
This research will also expand the scope of automated instruction.
The benefits of embedding the computational model within an
Intelligent Tutoring System parallel the potential contributions
of the model to decision aiding (as discussed above): (a)
The hybrid architecture can be utilized as a student model,
in order to tailor instruction to individual trainees. Student
models can be used, for example, to select and sequence cases
and examples, to regulate the level of difficulty, to diagnose
specific problems in user domain models or in decision making
processes, and to provide adaptive feedback. (b) The hybrid
system can also be used in an ITS as the basis for a self-improving
expert model of the domain. This expert model can, in turn,
be used as the basis of coaching that provides hints, advice,
and feedback when there are discrepancies between the inferred
student domain model and the expert domain model. (c) Metacognitive
processes embedded within the hybrid model provide a naturalistic
basis for an set of instructional strategies or rules for
intervention. At the same time, they effectively model expert
processes of metacognitive monitoring and regulation. Intervention
strategies adopted by an ITS would reflect expert metacognitive
strategies for interrupting the flow of recognitional processes
(when time, stakes, and uncertainty warrant such interruption)
and for critiquing recognitional models for such problems
as incompleteness, unreliability, and conflict.
In previous work for the Tactical Decision Making under Stress
(TADMUS) program, a cognitive and naturalistic approach to
training CIC decision making skills has been developed. The
basic premise of the training is that proficient decision
making requires critical thinking skills. These skills are
embodied in effectively structured domain knowledge and in
strategies for monitoring and regulating the use of that knowledge.
The critical thinking training has resulted in improvements
in performance in tests with department head students at the
Surface Warfare Officers' School, Newport, RI and with individual
students at the Naval Post Graduate School, and is being extended
to the context of team training.
The cognitive concepts of a recognition / metacognition model
which have been explored in this project were integrated into
a prototype DSS (Decision Support System) for the Navy CIC.
Working with NAWC/TSD and SPAWAR, CTI developed displays and
behaviors for the DSS. These were tested experimentally and
found to significantly improve decision-making performance.
In addition, the Navy is interested in integrating the computational
model of a recognitional / metacognitive agent into the DSS.
It would serve a decision support role and aid the CO and
TAO in developing a situation estimate and elaborating appropriate
responses. In particular, the agent would provide support
for reasoning about unreliable, conflicting, and incomplete
evidence and the stakes involved in delaying decisions and
acting. Another on-going application of this technology is
in the context of an Army project on training battlefield
critical thinking skills. The hybrid system is being utilized
to (1) provide feedback to officers regarding their situation
assessments and decisions in battlefield scenarios and (2)
represent and filter information through coordinated mental
models.
In this work we used two different sets of scenarios.
One was developed under the TADMUS (Tactical Decision Making
Under Stress) program for the DEFTT simulator. The second set
was developed for Douglas Towne's Rides-based CIC simulation
package. In the course of our research, we developed a tool
for translating the DEFTT scenarios, to the extent possible,
into the format used by Towne's CIC simulation. In addition,
we developed a CIC kinematics simulation to be used with the
machine learning experiments. It uses the same scenario format
as Towne's.