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Our Lab's Research:
Ways Strategy Changes Can Improve
Problem Solving and Memory
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Our
lab's
research is directed at understanding how people acquire new mental
representations and change strategies as they solve problems or
study. We conduct laboratory studies to discover ways that we can
improve peoples' memory and problem-solving abilities. In problem
solving, we have been studying how planning enhances learning and how
people can learn to be more careful. In memory, we have studied
how ordinary people can improve their memory by spacing practice
differently or using new strategies for studying. Our studies of
the expert memorist Rajan show just how far memory can be improved with
practice. Graduate
students in
the lab receive training in both memory and problem solving, but
ultimately concentrate their efforts on the area they prefer.
Our lab
seeks to train future basic scientists for careers in research and
teaching, but we also have some applied projects. Our basic
research efforts mainly look at the strategies people use in various
laboratory tasks. A subtheme is the nature of executive processes
(like "working memory") and whether or how executive processes place
limits on the strategies people employ. Of course, our ultimate
interest isn't in studying tasks that are found only in laboratories --
we're interested in what those tasks tell us more generally about
problem solving and memory. Our applied work takes some of the
ideas we developed in the lab and applies them to everyday problems
such as improving decision making of drivers and traffic engineers, and
studying ways that medical doctors can improve the memories of older
adult patients who visit their offices. Memory Research
To get an idea of the
ultimate power of study strategies to improve learning, consider our
research on a memory expert named Rajan. Rajan is famous for
having learned tens of thousands of
digits of pi (3.141519...) and he's capable of learning lists of 50
digits with virtually perfect accuracy in about a minute of study
(Ericsson, Delaney, Weaver & Mahadevan, 2004). We concluded
that exceptional skills
derived from years of practice were responsible for Rajan's abilities,
and not innate talents. Not only memory experts show exceptional
memory: so do doctors,
musicians, and others (Ericsson & Delaney,
1999). Even in simple list learning experiments, people
can change strategies after self-evaluation. People
often switch from rehearsal-based study strategies to more elaborative
strategies. We have shown that these
strategy changes can be triggered by instructions to "forget"
earlier-learned material or by asking people to evaluate their own
performance (Sahakyan, Delaney & Kelley, 2004; Sahakyan &
Delaney, 2003), and that similar strategy
changes can affect the basis (or even the existence) of spacing effects
(Delaney & Knowles, 2005). Spacing effects
refer to the well-known finding that the same amount of study time is
more
effectively used by viewing each item on a list twice than by viewing
each item only once (but for longer). Problem Solving
& Decision Making Research Our other work is
concerned with problem solving and decision processes. Executive
processes and memory strategies are, of course, implicated in the ways
people approach problem solving and decision making, but there are
other factors that may be even more important. One kind of
strategy we have studied is planning, including how planning strategies
change over time, why people choose particular planning strategies, and
how planning can facilitate learning (Delaney, Ericsson
& Knowles, 2004). More recently, we have been
exploring ways
to teach people to avoid illegal moves (moves that break
rules). Illegal moves are important because they limit planning
ahead and may lead to important consequences when errors are costly --
such as in air traffic control tasks. We have developed a
framework for understanding how a
particular manipulation that reduces illegal moves does its work
(Knowles & Delaney, in press). Methods for
Investigating Memory and Thinking Our lab has refined
methods for attacking scientific problems. In general, all of
these approaches are aimed at discovering the strategies that people
use on various tasks and on how those strategies impact various
psychological effects. Gaining control over peoples' strategies often leads to insights into the basic theoretical mechanisms that underlie various phenomena. The same three basic laboratory techniques have proven successful for our lab in a variety of different domains: tracking strategies, constraining strategies, and controlling strategies. Tracking strategies involves collecting concurrent or retrospective verbal reports (a technique made famous by my graduate advisor, K. Anders Ericsson). Naturally, it is important to know what techniques elicit valid verbal reports, and what produces mere introspective guesswork! Constraining strategies involves taking steps to interfere with the mechanisms assumed to underlie exceptional performance in a task. Tasks can often be designed to reduce the level of performance only if people are using a particular strategy. Finally, controlling strategies involves instructing people to approach the task in a certain fashion. In this way, strategy variability is reduced or eliminated. In order to integrate the results of this work with existing phenomena, we are currently trying to produce computer-based mathematical models of various phenomena using the ACT-R cognitive architecture, the Atwood/Polson process model for problem solving, and the modified SAM model designed to account for interference effects in memory. |