Online research in philosophy

Under general assumptions, the Turing test can be easily passed by an appropriate algorithm. I show that for any test satisfying several general conditions, we can construct an algorithm that can pass that test, hence, any operational definition is easy to fulfill. I suggest a test complementary to Turing's test, which will measure our understanding of the human mind. The Turing test is required to fix the operational specifications of the algorithm under test; under this constrain, the additional test simply consists in measuring the length of the algorithm.

We use the Newell Test as a basis for evaluating ACT-R as an effective architecture for cognitive engineering. Of the 12 functional criteria discussed by Anderson & Lebiere (A&L), we discuss the strengths and weaknesses of ACT-R on the six that we postulate are the most relevant to cognitive engineering.

Newell was a founder of artificial intelligence (AI) and a pioneer in the use of computer simulations in psychology. In collaboration with J. Cliff Shaw and Herbert A. <span class='Hi'>Simon</span>, Newell developed the first list-processing programming language as well as the earliest computer programs for simulating human problem solving. Over a long and prolific career, he contributed to many techniques, such as protocol analysis and heuristic search, that are now part of psychology and computer science. Colleagues remembered Newell for his deep commitment to science, his care for details, and his inexhaustible energy.

This commentary questions the applicability of the Newell Test for evaluating the utility of connectionism. Rather than being a specific theory of cognition (because connectionism can be used to model nativist, behaviorist, or constructivist theories), connectionism, we argue, offers researchers a collection of computational and conceptual tools that are particularly useful for investigating and rendering specific fundamental issues of human development. These benefits of connectionism are not well captured by evaluating it against Newell's criteria for a unified theory of cognition.

Although we agree with Newell and Anderson & Lebiere (A&L) that a unified theory of cognition is needed to advance cognitive science, we disagree on how to achieve it. A hybrid system can score high in the Newell Test but may not offer a veridical and coherent theory of cognition. A multilevel approach, involving theories at both psychological and brain levels, is suggested.

This commentary defines an additional characteristic of human learning. The nature of this test is different from the ones by Newell: This is a hard, pass/fail type of test. Thus a theory of cognition cannot partially satisfy this test; it either conforms to the requirement fully, or it doesn't. If a theory of cognition cannot satisfy this property of human learning, then the theory is not valid at all.

“Conceptual coordination” analysis bridges connectionism and symbolic approaches by positing a “process memory” by which categories are physically coordinated (as neural networks) in time. Focusing on dysfunctions and odd behaviors, like slips, reveals the function of consciousness, especially constructive processes that are often taken for granted, which are different from conventional programming constructs. Newell strongly endorsed identifying architectural limits; the heuristic of “diagnose unusual behaviors” will provide targets of opportunity that greatly strengthen the Newell Test.

The Newell Test is an important step in advancing our understanding of cognition. One critical constraint is missing from this test: A cognitive architecture must be self-contained. ACT-R and connectionism fail on this account. I present an alternative proposal, called Distributed Adaptive Control (DAC), and expose it to the Newell Test with the goal of achieving a clearer specification of the different constraints and their relationships, as proposed by Anderson & Lebiere (A&L).

The Newell Test is an ambitious and promising project, but not without pitfalls. Some of the current criteria are not theoretically neutral, whereas others are unhelpful. To improve the test, the learning and development criteria are reviewed and revised, which suggests adding a maturation criterion as well. Such changes should make the Newell Test more general and useful.

The Newell Test as it is proposed by Anderson & Lebiere (A&L) has the disadvantage of being too positivistic, stressing areas a theory should cover, instead of attempting to exclude false predictions. Nevertheless, Newell's list can be used as the basis for a more stringent test with a stress on the falsifiability of the theory.