Ergodic theorems and the basis of science

New results in ergodic theory show that averages of repeated measurements will typically diverge with probability one if there are random errors in the measurement of time. Since mean-square convergence of the averages is not so susceptible to these anomalies, we are led again to compare the mean and pointwise ergodic theorems and to reconsider efforts to determine properties of a stochastic process from the study of a generic sample path. There are also implications for models of time and the interaction between observer and observable.Supported in part by NSF Grant DMS-9203489. The author thanks Klaus Schmidt and Máté Wierdl for illuminating discussions.     

Johannes Daubert als Ästhetiker

Ohne Zusammenfassung     

Characteristics of Adult Caretakers of Children and Youth Served by an Urban Child Welfare Agency

The child welfare system of the early 1990s was marked by the proliferation of home-based services. Research on the effectiveness of various home-based interventions indicates results have been equivocal. The need to make explicit the specific characteristics of the adults and children targeted for home-based services, particularly families from diverse cultural backgrounds, has been identified as a critically needed contribution to the literature. In this study, the characteristics and service utilization experiences of adults and families served in an urban, home-based, child welfare program was examined. The results are discussed in relation to findings on the characteristics and experiences of adults and families served in other settings. Implications for future research and service delivery are discussed.     

A method for utilizing a single port for multiple functions on the IBM PC or compatible system

Psychological experiments often require the control of a large number of output lines; unfortunately, the IBM PC provides only 32 8-bit ports through which communication may be implemented without risk of conflict with other software/hardware. A single 8-bit port may be used to control a large number of devices by adding appropriate decoder logic between the computer’s port and the devices that are to be controlled. Software and hardware are presented that illustrate this technique by controlling an 8-digit light-emitting diode display with a single IBM PC output port.     

Semantic interference on a phonological task in illiterate subjects

Previous research suggests that learning an alphabetic written language influences aspects of the auditory-verbal language system. In this study, we examined whether literacy influences the notion of words as phonological units independent of lexical semantics in literate and illiterate subjects. Subjects had to decide which item in a word- or pseudoword pair was phonologically longest. By manipulating the relationship between referent size and phonological length in three word conditions (congruent, neutral, and incongruent) we could examine to what extent subjects focused on form rather than meaning of the stimulus material. Moreover, the pseudoword condition allowed us to examine global phonological awareness independent of lexical semantics. The results showed that literate performed significantly better than illiterate subjects in the neutral and incongruent word conditions as well as in the pseudoword condition. The illiterate group performed least well in the incongruent condition and significantly better in the pseudoword condition compared to the neutral and incongruent word conditions and suggest that performance on phonological word length comparisons is dependent on literacy. In addition, the results show that the illiterate participants are able to perceive and process phonological length, albeit less well than the literate subjects, when no semantic interference is present. In conclusion, the present results confirm and extend the finding that illiterate subjects are biased towards semantic-conceptual-pragmatic types of cognitive processing.     

Cognitive processes in the Extrinsic Affective Simon Task: a task-set switching account of EAST effects

Recently, De Houwer (2003) introduced the Extrinsic Affective Simon Task (EAST) as a new procedure for the indirect assessment of attitudes. In the present paper, we propose an explanation of EAST effects based on a task-set switching account. Specifically, we argue that EAST effects result from difficulties in efficiently switching between two different task sets. Results from two experiments support the assumptions of the task-set switching account: While there were strong EAST effects in task-shift trials, no robust effects were found in task-repetition trials. In Experiment 2, the robustness of this task-shift effect on the EAST was demonstrated: Visual similarity between concept and attribute stimuli did not qualify the task-shift effects. Implications for the interpretation of EAST effects are discussed.