Output decay in immediate serial recall : Speech time revisited

Original article can be found at: http://www.sciencedirect.com Copyright Elsevier [Full text of this article is not available in the UHRA]Four experiments reexamined the hypothesis that immediate serial recall is limited by the spoken duration of list items during output. In all the experiments, spoken serial recall was measured for visually presented words of short and long duration. The duration of first- and second-half list items was varied independently. Experiment 1 used the disyllabic words from Lovatt, Avons, and Masterson (2000). No main effect of the duration of words recalled first was obtained on accuracy of recall. Experiment 2 used the disyllabic words from Cowan et al. (1992). For this set of words, placing long items at the beginning of the list brought about a decrease in recall as predicted by theories of output decay. Experiment 3 confirmed that an effect of duration of words recalled first was confined to the Cowan et al. words, but this effect vanished when the first-half errors were statistically controlled or excluded. Experiment 4 extended these findings to the disyllabic words originally selected by Caplan, Rochon, and Waters (1992) and a new set of three-syllable words. For all these word sets, speech time during output differed for the long and short words. However, for two sets there was no effect of first-half word duration, and for the other two sets first-half word duration was confounded with first-half error rate. Taken together, the results provide no evidence that the spoken duration of early list items directly affects later recall, as predicted by the speech time hypothesis.Peer reviewe

Presence: Concept, determinants and measurement

The concept of presence, i.e. the sensation of `being there' in a mediated environment, has received substantial attention from the virtual reality community, and is becoming increasingly relevant both to broadcasters and display developers. Although research into presence is still at an early stage of development, there is a consensus that presence has multiple determinants. To identify and test which parameters affect presence, a reliable, robust and valid means of measuring presence is required. In this paper, we describe the categories of factors thought to have an impact on presence. Furthermore, we present an overview of various approaches taken to measuring presence, which can be divided into two general categories: subjective measures and objective corroborative measures. Since presence is a subjective experience, the most direct way of assessment is through users' subjective report. This approach has serious limitations however, and should be used judiciously. Objective measures, such as postural, physiological or social responses to media, can be used to corroborate subjective measures, thereby overcoming some of their limitations. At present, the most promising direction for presence measurement is to develop and use an aggregate measure of presence that is comprised of both subjective and objective components, tailored to the specific medium under study

Presence : concept, determinants and measurement

The concept of presence, i.e. the sensation of 'being there' in a mediated environment, has received substantial attention from the virtual reality community, and is becaming increasingly relevant both to broadcasters and display developers. Although research into presence is still at an early stage of development, there is a consensus that presence has multiple determinants. To identify and test which parameters affect presence, a reliable, robust and valid means of measuring presence is required. In this paper, we describe the categories of factors thought to have an impact on presence. Furthermore, we present an overview of various approaches taken to measuring presence, which can be divided into two general categories: subjective measures and objective corroborative measures. Since presence is a subjective experience, the most direct way of assessment is through users' subjective report. This approach has serious limitations however, and should be used judiciously. Objective measures, such as postural, physiological or social responses to media. can be used to corroborate subjective measures, thereby overcoming some of their limitations. At present, the most promising direction for presence measurement is to develop and use an aggregate measure of presence that is comprised of both subjective and objective components, tailored to the specific medium under study