Constructive mathematics and unbounded operators — A reply to Hellman

It is argued that Hellman's arguments purporting to demonstrate that constructive mathematics cannot cope with unbounded operators on a Hilbert space are seriously flawed, and that there is no evidence that his thesis is correct.     

Interactive computation is interaction with what?: A reply to Clark

In this response essay, we argue that Andy Clark’s assessment of our position on cyborgs is rooted in a misconception of the notion of “interaction” that we advance.     

Teachers as role models: Are there gender differences in microcomputer-based mathematics and science instruction?

This study examines whether male and female teachers differ in (a) their background or training for instructional uses of microcomputers and (b) their uses of microcomputers to teach mathematics and science. Research carried out in 60 classrooms, 49 schools, and 25 districts in California provided data on district and school microcomputer policies; classroom contexts; and teachers' characteristics, instructional decisions, and practices. A secondary analysis of these data indicated that district and school characteristics and classroom organization and composition did not differ, by and large, among male and female teachers. Furthermore, gender was unrelated to teachers' subject matter and computer knowledge, patterns of microcomputer-based instruction, and instructional decisions and practices. Both female and male teachers provide leadership in the microcomputer movement, have the relevant training and experience which contributes to microcomputer use, use microcomputers for instruction in a variety of ways, and present equally viable role models.Funded by the National Institute of Education (NIE), this study was restricted to California for budgetary reasons. Nevertheless, California appears to be representative of microcomputer use in other leading states (Chambers & Bork, 1980).     

Platonism and laws: A reply to Demetra Sfendoni‐Mentzou

This paper is a reply to Demetra Sfendoni‐Mentzou; it defends a realist—indeed a platonist—account of laws of nature.     

Stars and steam engines: To what extent do thermodynamics and statistical mechanics apply to self-gravitating systems?

Synthese - Foundational puzzles surround (Newtonian) gravitational thermal physics—a realm in which stars are treated as akin to molecules in a gas. Whether such an enterprise is successful...     

Does degree of asymmetry relate to performance? A reply to Boles and Barth

In a recent critique Boles and Barth (2011) argue that their prior study investigating asymmetry/performance relationships (Boles, Barth, & Merrill, 2008) uncovered the “true” association (i.e., negative correlation) between lateralization of visual lexical processes and word recognition performance. They contend that our study reporting positive correlations of lexical asymmetry and reading performance (Chiarello et al., 2009) was flawed and hence inconclusive. In this response we address the two major objections raised by Boles and Barth (2011) regarding our selection of tasks and asymmetry measures. We conclude that the Boles and Barth principle of task purity is not relevant to the stated aims of our investigation, and that our linear regression method of measuring asymmetry is valid given the high level of accuracy for the tasks we reported. Because the aims of each investigation differed, we argue that it is unwise to attempt to fit each study into the framework favored by Boles and Barth (2011).     

Unskilled and unaware--but why? A reply to Krueger and Mueller (2002)

J. Kruger and D. Dunning (1999) argued that the unskilled suffer a dual burden: Not only do they perform poorly, but their incompetence robs them of the metacognitive ability to realize it. J. Krueger and R. A. Mueller (2002) replicated these basic findings but interpreted them differently. They concluded that a combination of the better-than-average (BTA) effect and a regression artifact better explains why the unskilled are unaware. The authors of the present article respectfully disagree with this proposal and suggest that any interpretation of J. Krueger and R. A. Mueller's results is hampered because those authors used unreliable tests and inappropriate measures of relevant mediating variables. Additionally, a regression-BTA account cannot explain the experimental data reported in J. Kruger and D. Dunning or a reanalysis following the procedure suggested by J. Krueger and R. A. Mueller.     

The frozen cyborg: A reply to Selinger and Engström

Selinger and Engstrom, A moratorium on cyborgs: Computation, cognition and commerce, 2008 (this issue) urge upon us a moratorium on ‘cyborg discourse’. But the argument underestimates the richness and complexity of our ongoing communal explorations. It leans on a somewhat outdated version of the machine metaphor (exemplified perhaps by a frozen 1970’s Cyborg). The modern cyborg, informed by an evolving computational model of mind, can play a positive role in the critical discussions that Selinger and Engstrom seek.     

Commentary: What are behavior systems and what use are they?

The contributions of this symposium on behavior systems are summarized and evaluated by considering two questions: (1) What is a behavior system? (2) What use to the learning theorist are behavior systems? Two examples of behavior systems from the classical ethological literature are compared with the behavior systems discussed in the symposium, and some similarities and differences in the type of analyses used are discussed. Analysis of the pre-organized species-typical behavior systems relevant to the unconditioned stimuli or reinforcers in learning experiments can contribute performance rules and better understanding of the conditions and contents of learning. The organization of behavior systems can also provide important clues to the neural circuitry underlying behavior, and a behavior systems approach can raise novel questions concerning learning and behavioral development. Possible future directions for the behavior systems approach are briefly discussed.     

Event-based and emergent timing: dichotomy or continuum? A reply to Repp and Steinman (2010)

B. H. Repp and S. R. Steiman (2010) suggested that event-based and emergent timing, usually conceived as mutually exclusive modes of timing, could in fact coexist in a single activity. According to this point of view, rhythmic activities could exploit mixtures of control modes, in which the relative importance of event-based and emergent components could depend on task characteristics. This point of view, in the opinion of the authors of the present article, corresponds to a fundamental misunderstanding of the theoretical basis of the event-based and emergent distinction, and is not supported by any experimental evidence. However, they present some new results that could support new lines of reasoning for the future developments of research in this domain.