Practical Arguments for Theoretical Theses

Pascals wager is expounded as a paradigm case of a practical,decision-theoretical argument for acting as if a proposition is true when wehave no theoretical reasons to accept or reject it (1.1.–1.2.). Thoughthe paradigm is fallacious in various respects there are valid and adequatearguments for acting as if certain propositions are true: that theoreticalentities exist, that there are material perceptual objects, that the worldis uniform across time (1.3). After this analysis of examples the authorsgeneral approach for developing criteria for the validity and adequacy oftypes of argument (2.1.) is applied: Having discussed some problems(2.2.–2.3.), a general epistemic principle for such pascal argumentsis developed, which characterizes their premisses and, if introduced as anadditional premiss, can make them deductively valid (2.4).     

WHAT IT FEELS LIKE TO BE IN A SUPERPOSITION. AND WHY

This paper attempts an interpretation of Everett's relative state formulation of quantum mechanics that avoids the commitment to new metaphysical entities like worlds or minds. Starting from Everett's quantum mechanical model of an observer, it is argued that an observer's belief to be in an eigenstate of the measurement (corresponding to the observation of a well-defined measurement outcome) is consistent with the fact that she objectively is in a superposition of such states. Subjective states corresponding to such beliefs are constructed. From an analysis of these subjective states and their dynamics it is argued that Everett's pure wave mechanics is subjectively consistent with von Neumann's classical formulation of quantum mechanics. It follows from the argument that the objective state of a system is in principle unobservable. Nevertheless, an adequate concept of empirical reality can be constructed.     

Coherence and Conservatism in the Dynamics of Belief

In this paper I discuss the foundations of a formal theory of coherent and conservative belief change that is (a) suitable to be used as a method for constructing iterated changes of belief, (b) sensitive to the history of earlier belief changes, and (c) independent of any form of dispositional coherence. I review various ways to conceive the relationship between the beliefs actually held by an agent and her belief change strategies (that also deal with potential belief sets), show the problems they suffer from, and suggest that belief states should be represented by unary revision functions that take sequences of inputs. Three concepts of coherence implicit in current theories of belief change are distinguished: synchronic, diachronic and dispositional coherence. Diachronic coherence is essentially identified with what is known as conservatism in epistemology. The present paper elaborates on the philosophical motivation of the general framework; formal details and results are provided in a companion paper.     

Exact and best confidence intervals for the ability parameter of the Rasch model

A commonly used method to evaluate the accuracy of a measurement is to provide a confidence interval that contains the parameter of interest with a given high probability. Smallest exact confidence intervals for the ability parameter of the Rasch model are derived and compared to the traditional, asymptotically valid intervals based on the Fisher information. Tables of the exact confidence intervals, termed Clopper-Pearson intervals, can be routinely drawn up by applying a computer program designed by and obtainable from the author. These tables are particularly useful for tests of only moderate lengths where the asymptotic method does not provide valid confidence intervals.     

Contact-free measurement of heart rate, respiration rate, and body movements during sleep

We describe a noncontact method for the ambulant measurement of basic sleep physiology parameters in humans, particularly for field studies involving sleep research and sleep disturbances. This method traces the body movements, respiration, and heart action of a person at rest or asleep on a bed, using four high-resolution force sensors installed under the bedposts. The recoil movement of the body at each heartbeat, known as the cardioballistic effect, as well as the lifting and lowering of the thorax, while breathing, causes very small shifts of the center of gravity of the bed and the subject. These shifts are reflected in the altering force distributions across the four sensors. Cardiac and respiratory parameters and the subject’s movement activity can be calculated from the sensor signals. Neither electrodes nor other kinds of transducers are in direct contact with the subject, which is the main advantage of this technique over conventional methods. Laboratory experiments were carried out to estimate validity and practicability. The method has been found to be adequate, especially for automated and unattended sleep-data collection over long periods of time.     

Computer supported mathematics with Ωmega

Classical automated theorem proving of today is based on ingenious search techniques to find a proof for a given theorem in very large search spaces—often in the range of several billion clauses. But in spite of many successful attempts to prove even open mathematical problems automatically, their use in everyday mathematical practice is still limited.The shift from search based methods to more abstract planning techniques however opened up a paradigm for mathematical reasoning on a computer and several systems of that kind now employ a mix of interactive, search based as well as proof planning techniques.The Ωmega system is at the core of several related and well-integrated research projects of the Ωmega research group, whose aim is to develop system support for a working mathematician as well as a software engineer when employing formal methods for quality assurance. In particular, Ωmega supports proof development at a human-oriented abstract level of proof granularity. It is a modular system with a central proof data structure and several supplementary subsystems including automated deduction and computer algebra systems. Ωmega has many characteristics in common with systems like NuPrL, CoQ, Hol, Pvs, and Isabelle. However, it differs from these systems with respect to its focus on proof planning and in that respect it is more similar to the proof planning systems Clam and λClam at Edinburgh.     

The influence of the immediate visual context on incremental thematic role-assignment: evidence from eye-movements in depicted events

Studies monitoring eye-movements in scenes containing entities have provided robust evidence for incremental reference resolution processes. This paper addresses the less studied question of whether depicted event scenes can affect processes of incremental thematic role-assignment. In Experiments 1 and 2, participants inspected agent-action-patient events while listening to German verb-second sentences with initial structural and role ambiguity. The experiments investigated the time course with which listeners could resolve this ambiguity by relating the verb to the depicted events. Such verb-mediated visual event information allowed early disambiguation on-line, as evidenced by anticipatory eye-movements to the appropriate agent/patient role filler. We replicated this finding while investigating the effects of intonation. Experiment 3 demonstrated that when the verb was sentence-final and thus did not establish early reference to the depicted events, linguistic cues alone enabled disambiguation before people encountered the verb. Our results reveal the on-line influence of depicted events on incremental thematic role-assignment and disambiguation of local structural and role ambiguity. In consequence, our findings require a notion of reference that includes actions and events in addition to entities (e.g. Semantics and Cognition, 1983), and argue for a theory of on-line sentence comprehension that exploits a rich inventory of semantic categories.     

Multiple,speeded assessments: Initial evidence on subgroup differences and applicant perceptions

Recently, shorter assessments have emerged as potential alternatives for more resourceful traditional selection approaches. Multiple, speeded assessments (MSAs) represent such an alternative. In MSAs, candidates participate in a large number of short (a maximum of 5 min), behavioral simulations in which they face a variety of job situations. Initial psychometric evidence on the validity of MSAs is promising. Yet, validity represents only one piece of evidence. It is not known whether MSAs disadvantage specific subgroups, which may inhibit diversity. There is also no information on candidates' experience of going through an MSA, which is pivotal for the attractiveness of the organization's selection process. Therefore, this study investigates an MSA in terms of subgroup differences (gender and nationality) and applicant perceptions. Master of Business Administration (MBA) students (N = 96) proceeded through 18 short role-plays sampling junior management situations. Score differences between men and women were negligible. Yet, there were large score differences between national citizens and foreigners. There was no evidence for predictive bias for nationality, though. Of the applicant reaction measures, interpersonal treatment perceptions contributed most to overall fairness perceptions. These findings add to the evidence in support of MSAs, while also stressing to remain vigilant for potential score differences among subgroups.