Video streaming into the mainstream

Changes in Internet technology are making possible the delivery of a richer mixture of media through data streaming. High-quality, dynamic content, such as video and audio, can be incorporated into Websites simply, flexibly and interactively. Technologies such as G3 mobile communication, ADSL, cable and satellites enable new ways of delivering medical services, information and learning. Systems such as Quicktime, Windows Media and Real Video provide reliable data streams as video-on-demand and users can tailor the experience to their own interests. The Learning Development Centre at the University of Portsmouth have used streaming technologies together with e-learning tools such as dynamic HTML, Flash, 3D objects and online assessment successfully to deliver on-line course content in economics and earth science. The Lifesign project--to develop, catalogue and stream health sciences media for teaching--is described and future medical applications are discussed.

A computerized adaptive testing system for speech discrimination measurement: the Speech Sound Pattern Discrimination Test

A computerized, adaptive test-delivery system for the measurement of speech discrimination, the Speech Sound Pattern Discrimination Test, is described and evaluated. Using a modified discrimination task, the testing system draws on a pool of 130 items spanning a broad range of difficulty to estimate an examinee's location along an underlying continuum of speech processing ability, yet does not require the examinee to possess a high level of English language proficiency. The system is driven by a mathematical measurement model which selects only test items which are appropriate in difficulty level for a given examinee, thereby individualizing the testing experience. Test items were administered to a sample of young deaf adults, and the adaptive testing system evaluated in terms of respondents' sensory and perceptual capabilities, acoustic and phonetic dimensions of speech, and theories of speech perception. Data obtained in this study support the validity, reliability, and efficiency of this test as a measure of speech processing ability.

Working memory capacity and comprehension processes in deaf readers

This research studied deaf students' performance on memory span and component reading tasks that incorporated processes involved in higher level comprehension. The instruments developed in the study provide the basis for the measurement of functional working memory capacity, vocabulary knowledge, domain-relevant knowledge, and inference abilities. Multiple regression analysis was used to construct models that show the contributions of the independent assessments to reading comprehension ability. Overall results suggest that working memory operates as a general executive system, as indicated by significant correlations between subjects' performance on reading and nonreading tasks. Limitations in vocabulary knowledge continue to pose problems in reading for deaf individuals. General or procedural knowledge also plays a part in reading comprehension processes.

The relevance of aquatic organisms' lipid content to the toxicity of lipophilic chemicals: toxicity of lindane to different fish species

The acute toxicity (48-hr LC50) of lindane (gamma-HCH) to 16 fish species, belonging to eight families, ranges from 22 to 900 micrograms/liter (mean: 150 micrograms/liter). A significant positive linear relationship between the lipid content (% on a wet weight basis) of the fishes and their toxicity to gamma-HCH was found. If the toxicity is referred to 1% lipid, 48-hr LC50 values range between 13.2 and 32 micrograms/liter, and thus the coefficient of variation of the mean is reduced from 139 to 22%. It is concluded that the lipids of aquatic organisms serve as a protective reservoir against the toxic effects of lindane and other lipophilic, relatively persistent organic chemicals, because they are bioconcentrated mainly in the body lipids. Therefore, in organisms with high lipid content, only a relatively small fraction of the hydrophobic chemical can reach target organs (nerves, liver, etc.) and/or receptors. For comparing toxicity data of organic chemicals to aquatic organisms, the total lipid content of the organisms must be considered. The results of this investigation are important in comparative environmental toxicology for risk assessment of freshwater and marine organisms.

The Classroom Communication Ease Scale. Development of a self-report questionnaire for mainstreamed deaf students

This study describes efforts to develop a self-report psychological scale (CCES: Classroom Communication Ease Scale) to provide information about the extent to which mainstreamed deaf students think that they communicate effectively with teachers and peers, as well as how they feel about their communication experiences in mainstreamed classrooms. Data obtained from administration of the CCES to 50 deaf students enrolled in baccalaureate programs at a postsecondary technical institution were subjected to Rasch rating scale analysis. Fit of data to the measurement model resulted in a set of 42 items that empirically define the concept of "communication ease" in its cognitive aspects and a set of 21 items that elaborate the concept further in terms of its affective aspects.

Simple discrimination isn't really simple. A confirmatory analysis of the Speech Sound Pattern Discrimination Test

This paper reports the results of a componential analysis of items comprising the Speech Sound Pattern Discrimination Test (SSPDT). The SSPDT, developed by Bochner et al. (1986), uses a closed-set sentence discrimination task to assess the auditory speech processing skill of severely and profoundly hearing-impaired individuals. A set of components reflecting differences in the phonetic and task-related characteristics of the test stimuli was developed, and the contributions of the components to discrimination task difficulty were evaluated using linear regression methodology. Discrimination task difficulty indices were transformations of percent-correct scores, resulting from fit of the SSPDT data to the Rasch measurement model. Three of the hypothesized components (one spectral, one temporal, and one task-related) entered a stepwise regression solution. These components have an intrinsic role in the construct validity of the instrument. The structure of the discrimination task, however, is more complex than might be suspected, because 'same' or matching test stimuli showed advantages in ease of discriminability compared with their 'different' or non-matching counterparts. The study findings will facilitate development of an enlarged item bank, and aid in the interpretation of test scores.

A new protocol for assessing viseme perception in sentence context: the lipreading discrimination test

Forty-six hearing-impaired young adults were tested with a newly developed instrument that requires a discrimination response to assess viseme perception as a component of lipreading performance. Stimuli were videotaped sentences that differed on half of the trials from a captioned target sentence by one viseme embedded in the middle of the sentence. Discrimination within six visual categories was tested: gross syllable pattern, consonant articulation--lips, consonant articulation--tongue, vowel articulation--extreme lip shapes, vowel articulation--graded lip shapes, and vowel articulation--jaw movement. Test data were analyzed using an item response theory model. The results indicated that the test data conformed to the expectations of the Rasch model for person measurement. Relationships among subjects' test scores and communication characteristics also were examined. The data provide evidence that the test protocol, at this early stage of development, is useful for assessing at least one perceptual component of lipreading performance.

A closed-set sentence protocol for assessing speech discrimination in deaf individuals: the speech sound pattern discrimination test

Forty hearing-impaired young adults were tested with a newly developed instrument designed to assess auditory speech processing skill. Analyses indicated that the resulting test data could be characterized in terms of the Rasch model for person measurement. Evidence of the scale's empirical validity also was obtained. The instrument uses a closed-set sentence discrimination task, and appears to be useful over a fairly wide range of hearing losses.

Ego development and psychopathology: a study of hospitalized adolescents

This paper explores the relationship between ego development and psychiatrically relevant behaviors in a group of hospitalized adolescents. Building on Loevinger's model of ego development, we administered the Sentence Completion Test to 114 adolescent girls and boys. To study psychiatric symptoms, Achenbach and Edelbrock's Child Behavior Checklist was used. With these procedures, the Achenbach and Edelbrock factor scores were compared to ego stage using correlational and multiple regression analyses. Findings indicate significant negative correlations with the externalizing and internalizing factors as well as a variety of behavioral subscales. A significant relationship also exists between the total number of symptoms and ego development. Ego development is found to be an important predictor for the externalizing factor and 2 subscales after the background variables of age, sex, and SES are partialed out. Our discussion addresses the question of the relationship between stages and transitions in ego development in relation to psychopathology. In addition, "age-stage dysynchronies" are discussed as ways of understanding psychopathology from a developmental perspective.

An application of the pictorial scale of perceived competence and acceptance within an epidemiological survey

The Perceived Competence and Acceptance Scale for Younger Children (PCS) was examined in the course of an epidemiological survey of psychological disorders in children. Eighty-three children, aged 6 and 7 years, were administered several measures including the WISC-R, the WRAT, the Lie Scale for Children, and the PCS. Teachers provided ratings from a parallel version of the PCS and reported on the behavioral and social development of each child through the Child Behavior Checklist. Investigation of the psychometric characteristics of the PCS substantially replicates findings reported by its developers. The size and direction of correlations among the cognitive competence subscale of the PCS, achievement measures, and the Lie Scale indicate that children tend to more accurately report about this domain than others included in the PCS. Children who reported atypically high or low PCS levels were not found to differ from the remainder of the sample on two clinical indices. Children who tended to exaggerate PCS levels, as compared to teacher ratings, had significantly more behavior problems in school and were seen by two observers as more apt to be currently maladjusted.

Attachment to a special object at the age of three years: behavior and temperament characteristics

This study attempts to estimate the prevalence rate of attachment to a special object in a total population sample of three-year-olds drawn from an ongoing epidemiologic survey. The significance of object attachment at age three for the development of behavioral disturbance is assessed through two separate measures. Data from parental reports of temperament characteristics and observational codings of play sessions in the home setting are also presented. While the authors conclude that attachment to a special object is not related to behavioral disturbance, certain temperamental and play behavior characteristics were found to be significant.