Gandalf’s solution to the Newcomb problem

This article proposes a new theory of rational decision, distinct from both causal decision theory (CDT) and evidential decision theory (EDT). First, some intuitive counterexamples to CDT and EDT are presented. Then the motivation for the new theory is given: the correct theory of rational decision will resemble CDT in that it will not be sensitive to any comparisons of absolute levels of value across different states of nature, but only to comparisons of the differences in value between the available options within states of nature; however, the correct theory will also resemble EDT in that it will rely on conditional probabilities (not unconditional probabilities). The new theory gives a prominent role to the notion of a “benchmark” for each state of nature, by comparison with which the value of the available options in that state of nature are measured, and so it has been called the Benchmark Theory (BT). It is argued that BT gives the right verdict on the cases that seem to be counterexamples to CDT and EDT. Finally, some objections to BT are considered and answered.     

Darwin’s solution to the species problem

Biologists and philosophers that debate the existence of the species category fall into two camps. Some believe that the species category does not exist and the term ‘species’ should be eliminated from biology. Others believe that with new biological insights or the application of philosophical ideas, we can be confident that the species category exists. This paper offers a different approach to the species problem. We should be skeptical of the species category, but not skeptical of the existence of those taxa biologists call ‘species.’ And despite skepticism over the species category, there are pragmatic reasons for keeping the word ‘species.’ This approach to the species problem is not new. Darwin employed a similar strategy to the species problem 150 years ago.     

Three-dimensionalist’s semantic solution to diachronic vagueness

A standard response to the problem of diachronic vagueness is ‘the semantic solution’, which demands an abundant ontology. Although it is known that the abundant ontology does not logically preclude endurantism, their combination is rejected because it necessitates massive coincidence between countless objects. In this paper, I establish that the semantic solution is available not only to perdurantists but also to endurantists by showing that there is no problem with such ubiquitous and principled coincidence.     

A pragmatic solution to Ostertag’s puzzle

Gary Ostertag (Philos Stud 146:249–267, 2009) has presented a new puzzle for Russellianism about belief reports. He argues that Russellians do not have the resources to solve this puzzle in terms of pragmatic phenomena. I argue to the contrary that the puzzle can be solved according to Nathan Salmon’s (Frege’s puzzle, 1986) pragmatic account of belief reports, provided that the account is properly understood. Specifically, the puzzle can be solved so long as Salmon’s guises are not identified with sentences.     

Equating test scores—A maximum likelihood solution

Certain problems of equating are discussed. The maximum likelihood solution is presented for the following special equating problem: Two tests,U andV, are to be equated, making use of a third anchor test,W. The examinees are divided into two random halves. TestsU andW are administered to one half; testsV andW are administered to the other half. It is assumed that any practice effect or other effect, exerted byU andV onW, is the same forU and forV.     

Variational solution of the one-dimensional t–J model

A new variational scheme based on a modified Bethe–Peierls method is used to study the ground state properties of the one-dimensional t–J model. Expectation values are evaluated by cutting out a four-site cluster from a correlated Fermi sea, the ground state of which is described by a variational trial wave function. We study a generalized Gutzwiller state where nearest-neighbour hole–hole correlations are controlled variationally. From the electron concentration dependence of the ground state energy, we determine the true thermodynamic boundary where segregation into an electron-rich, and purely hole phase sets in. We also determine the spinodal line and pair susceptibilities. The variational method is applied also to an extended t–J–V model, where V is the coupling constant of the charge interaction term.     

Exemplarization: a solution to the problem of consciousness?

In recent publications, Keith Lehrer developed the intriguing idea of a special mental process??exemplarization??and applied it in a sophisticated manner to different phenomena such as intentionality, representation of the self, the knowledge of ineffable content (of art works) and the problem of phenomenal consciousness. In this paper I am primarily concerned with the latter issue. The target of this paper is to analyze whether exemplarization, besides explaining epistemic phenomena such as immediate and ineffable knowledge of experiences, can also solve the ontological problem of consciousness. In particular, Lehrer suggests that if we consider exemplarization, zombies cannot provide an argument for anti-physicalism. I argue that exemplarization offers neither a physicalist explanation of the conceivability of zombies nor an elucidating physicalist account of their impossibility. Therefore, exemplarization cannot offer a physicalist solution to the ??hard problem?? of consciousness.     

Agent causation as the solution to all the compatibilist’s problems

In a recent paper I argued that agent causation theorists should be compatibilists. In this paper, I argue that compatibilists should be agent causation theorists. I consider six of the main problems facing compatibilism: (i) the powerful intuition that one can’t be responsible for actions that were somehow determined before one was born; (ii) Peter van Inwagen’s modal argument, involving the inference rule (β); (iii) the objection to compatibilism that is based on claiming that the ability to do otherwise is a necessary condition for freedom; (iv) “manipulation arguments,” involving cases in which an agent is manipulated by some powerful being into doing something that he or she would not normally do, but in such a way that the compatibilist’s favorite conditions for a free action are satisfied; (v) the problem of constitutive luck; and (vi) the claim that it is not fair to blame someone for an action if that person was determined by forces outside of his or her control to perform that action. And in the case of each of these problems, I argue that the compatibilist has a much more plausible response to that problem if she endorses the theory of agent causation than she does otherwise.     

Maximum likelihood estimation of parameters of signal detection theory—A direct solution

Ogilvie and Creelman have recently attempted to develop maximum likelihood estimates of the parameters of signal-detection theory from the data of yes-no ROC curves. Their method involved the assumption of a logistic distribution rather than the normal distribution in order to make the mathematics more tractable. The present paper presents a method of obtaining maximum likelihood estimates of these parameters using the assumption of underlying normal distributions.This research was supported in part by grants from the National Institutes of Health, MH-10449-02, and from the National Science Foundation, NSF GS-1466.     

Hierarchical factor solution of coding and planning processes: Any new insights?

Hierarchical factor solution was used in the present paper in order to examine if two coding processes, simultaneous and successive, would load on a general 2nd level factor. It was further used to test if the coding processes and a factor representing planful behavior will not share the same general factor, revealing their relative independence as expected from a theoretical model of cognitive functions. Results supported the grouping of the coding tasks within a general factor, as well as the emergence of two general factors, one each for coding and planning. Further correlational evidence supported the relative independence of these two kinds of cognitive processes. These findings were discussed in the context of a general factor of intelligence.     

Examining foster care: A viable solution for placement of handicapped children?

Foster care for handicapped children has become a frequently used and even more frequently criticized procedure. Traditional methods of foster placement have resulted in a number of negative outcomes, especially for the placed children. Based on a review of some recent innovative foster care programs, this paper has isolated a number of options for the restructuring of the entire foster care delivery system. These options include: rigorous client evaluation, use of selection and training criteria for foster parents, matching of client needs to caregiver abilities in making placement decisions, and ongoing professional support and supervision after placement. Systematic consideration of these issues may help make foster care a more viable solution to the growing problem of home placement for handicapped children.     

Keep ‘hoping’ for rationality: a solution to the backward induction paradox

We formalise a notion of dynamic rationality in terms of a logic of conditional beliefs on (doxastic) plausibility models. Similarly to other epistemic statements (e.g. negations of Moore sentences and of Muddy Children announcements), dynamic rationality changes its meaning after every act of learning, and it may become true after players learn it is false. Applying this to extensive games, we “simulate” the play of a game as a succession of dynamic updates of the original plausibility model: the epistemic situation when a given node is reached can be thought of as the result of a joint act of learning (via public announcements) that the node is reached. We then use the notion of “stable belief”, i.e. belief that is preserved during the play of the game, in order to give an epistemic condition for backward induction: rationality and common knowledge of stable belief in rationality. This condition is weaker than Aumann’s and compatible with the implicit assumptions (the “epistemic openness of the future”) underlying Stalnaker’s criticism of Aumann’s proof. The “dynamic” nature of our concept of rationality explains why our condition avoids the apparent circularity of the “backward induction paradox”: it is consistent to (continue to) believe in a player’s rationality after updating with his irrationality.     

Metric unfolding: Data requirement for unique solution & clarification of Schönemann's algorithm

The object of this paper is to clarify Schönemann's unfolding algorithm and, in particular, to make it clear that the equations numbered (3.2) in Schönemann's [1970] article, which define Schönemann's solutions, are not a complete set of restraints for the purpose of defining metric unfoldings. Namely, Schönemann has transformed the original equations which define an unfolding to a set of linear and non-linear equations of which he uses only the linear equations to define his solutions. Given infallible data (solution(s) exist) Schönemann's solutions will include the correct solutions. If enough data are available so that there are enough linear equations to uniquely determine a single solution, then Schönemann's solution will coincide with the correct solution. LetP andQ denote the number of elements in the two sets of points, the interset distances of which are specified by the data in the unfolding problem. Letm denote the dimensionality of the Euclidean space into which these points are to be imbedded. If only the linear equations, numbered (18) herein, are to be used, then Schönemann gives the following data requirement for the solution to be uniquely determined: Max {P – 1,Q – 1} m(m + 3)/2. If the full set of linear and nonlinear equations (18–20) are used, then the amount of data required for a solution to be locally unique is relaxed toP +Q – 1 m(m + 3)/2. Both of these results assume that the equations are independent, which has not been proved.This study was supported by General Research Support Grant RR 5612 of the Division of Research Facilities and Resources, National Institutes of Health, U.S. Public Health Service.     

Is a person-affecting solution to the nonidentity problem impossible? Axiology,accessibility and additional people

Abstract

This paper considers two objections based in axiological considerations against the position that whether a given outcome, or possible future or world, is morally worse than a second world may depend in part on what is going on at a third world. Such a wide-angled approach to determining worseness is critical to the solution I have previously proposed in connection with the nonidentity problem. I argue that both objections fail.     

Experts,Novices, and the St. Petersburg paradox: Is one solution enough?

Although the controversy over the correct solution to the St. Petersburg paradox continues in the decision making literature, few of the solutions have been empirically evaluated. Via the development of alternative versions of the St. Petersburg game, we were able to empirically test some of these solutions. Experts and novices behaved in accordance with Treisman's expectation heuristic when bidding for the right to play the various versions of the St. Petersburg game. When subjects were asked their preferences among the game versions. novices continued to behave in accordance with the expectation heuristic but a plurality of experts seemed to follow another strategy. This preference reversal and its implications and possible causes are thoroughly discussed. An alternative theory which mimicks the expectation heuristic is considered, and generalizations of the expectation heuristic and the St. Petersburg Paradox for z-sided 'coins' (where z is any integer greater than or equal to 2) are presented. It appears that no one solution is yet rich enough for the St. Petersburg paradox.     

Psychologie et culture: vers une solution du “Babel”?

The current scientific debate on the relationship between psychological development and culture has been given different labels. These labels not only indicate divergent methodological approaches and heterogeneous research interests, but also represent distinct national scientific traditions. The authors suggest making a distinction between three main perspectives, namely “Cross-Cultural Psychology”, “Cultural Psychology” and “Psychologie Interculturelle”; a specific German approach called “Kulturpsychologie” is also briefly touched upon. These perspectives are described as distinct types of conceptual approaches and research strategies on the relationship between psychology and culture.     

Strong interactions between hydrogen in solid solution and stress-induced martensite transformation of Ni–Ti superelastic alloy

The role of the dynamic interactions between hydrogen in a solid solution and the stress-induced martensite transformation in hydrogen embrittlement has been investigated using trained Ni–Ti superelastic alloy. In a cyclic tensile test in the stress plateau region caused by stress-induced martensite and reverse transformations after hydrogen charging, a further decrease in the critical stress for the martensite transformation is observed. In addition, the number of cycles to fracture for a trained specimen is significantly larger than that for a non-trained specimen. Since most of the charged hydrogen is preferentially trapped in defects induced by training, the hydrogen embrittlement is considerably suppressed as a result of decreasing interactions between the hydrogen and the transformation. The present results indicate that hydrogen in a solid solution more strongly interacts with the stress-induced martensite transformation than hydrogen trapped in defects, thereby further enhancing the hydrogen embrittlement related to phase transformations.     

Impact du mode d’organisation de la tâche en résolution de problèmes sur la réussite et l’apprentissage. Résolution de problèmes et apprentissage

This research studies the impact of the instructional design in problems solving. Across several studies, Sweller, 1988, Sweller, 2003, Sweller, 2004 develop the Cognitive Load Theory. In this theory, the interrelationships between instructional variable, problem solving and learning are supported. But, these researches are concentrated on the aspect of problem itself. Others studies, in instructional design, wonder about the organization of a complete task (Paas et al., 2003). It seems of these researches that the mode of organization of a task influences the success of the task and more widely the quality of the knowledge, which can be elaborated during the realization of this task. The objective of our work is to bring to light all the importance of the design in a task with several problems. For that purpose, we compared a design based on a hierarchical organization of the difficulty of the problems (from the easiest to the most difficult) and a random presentation of the same problems. We present here three experiments using logical problems stemming from the minesweeper game. The results of the first experiment suggest that an organized mode of presentation compensates for the increase of the difficulty and facilitates a better success of the problems. The second experiment uses the same protocol, as the first one to which are added new problems as well as one paradigm of double task. The results show that the orderly mode of presentation also facilitates the elaboration of transferable knowledge with new problems. However, the distances from performances do not seem to be attributable in the cognitive load of the task. The third experiment brings more qualitative data, which come to support the first results. The verbalization of rules elaborated during the signing shows prevalence of the organized design. The subjective evaluation of the supplied mental effort confirms the insensitivity of the cognitive load in the mode of presentation of the task. So, the impact of the mode of presentation does not seem to ensue from a too important cognitive load during a random presentation but a lot of interest of an organized design.