Craig Locatis

Searching through cyberspace: the effects of link display and link density on information retrieval from hypertext on the World Wide Web

This study investigated information retrieval from hypertext on Internets World Wide Web (WWW). Significant main and interaction effects were found for both link density (number of links per display) and display format (in paragraphs or lists) on search performance. Low link densities displayed in list format produced the best overall results, in terms of search accuracy, search time, number of links explored, and search task prioritization. Lower densities affected user ability to prioritize search tasks and produced more accurate searches, while list displays positively affected all aspects of searching except task prioritization. The performance of novices and experts, in terms of their previous experience browsing hypertext on the WWW, was compared. Experts performed better, mostly because of their superior task prioritization.

Comparing In-Person, Video, and Telephonic Medical Interpretation

ABSTRACTBACKGROUNDUsing trained interpreters to provide medical interpretation services is superior to services provided on an ad hoc basis, but little is known about the effectiveness of providing their services remotely, especially using video.OBJECTIVETo compare remote medical interpretation services by trained interpreters via telephone and videoconference to those provided in-person.DESIGNQuasi-randomized control study.PARTICIPANTSTwo hundred and forty-one Spanish speaking patient volunteers, twenty-four health providers, and seven interpreters.APPROACHPatients, providers and interpreters each independently completed scales evaluating the quality of clinical encounters and, optionally, made free text comments. Interviews were conducted with 23 of the providers, the seven interpreters, and a subset of 30 patients. Time data were collected.RESULTSEncounters with in-person interpretation were rated significantly higher by providers and interpreters, while patients rated all methods the same. There were no significant differences in provider and interpreter ratings of remote methods. Provider and interpreter comments on scales and interview data support the higher in-person ratings, but they also showed a distinct preference for video over the phone. Phone interviews were significantly shorter than in-person.DISCUSSIONPatients rated interpretation services highly no matter how they were provided but experienced only the method employed at the time of the encounter. Providers and interpreters were exposed to all three methods, were more critical of remote methods, and preferred videoconferencing to the telephone as a remote method. The significantly shorter phone interviews raise questions about the prospects of miscommunication in telephonic interpretation, given the absence of a visual channel, but other factors might have affected time results. Since the patient population studied was Hispanic and predominantly female care must be taken in generalizing these results to other populations.

Hypermedia and instruction

Hypermedia and its educational applications are discussed in this article. Background information is provided, and software, knowledge representation, navigation, and authoring issues are described. Issues about hypermedias role in learning also are examined, and hypotheses are advanced about when it may be an effective teaching approach. One conclusion is that hypermedia has strengths and weaknesses and that it may become merely hyped media unless good teaching applications are developed.

The PDA as a portal to knowledge sources in a wireless setting.

Two recent parallel developments, the widespread deployment of wireless networks and increased use of handheld devices like the personal digital assistant (PDA), have contributed to the development of mobile access to the Internet. Recent surveys show that approximately 25% or more of physicians use PDAs. Although used mainly for personal information management and static medical applications, PDAs have capabilities to connect to the Internet. We studied the use of handheld devices to access MEDLINE and other knowledge sources in a wireless setting.

Searching through cyberspace: the effects of link cues and correspondence on information retrieval from hypertext on the World Wide Web

The effects of link cues and link correspondence on search performance were investigated using a core hypertext document with external links to other resources on the World Wide Web. Although subjects were to search for information in the core document, cues indicating links were to resources outside the search space did not affect performance. Subjects were not explicitly told the meaning of the cues and the duration of the search tasks was not sufficient for subjects to surmise their meaning. Correspondence of wording in search tasks to wording in links positively affected search efficiency, but not search accuracy. The implications of this finding and the need for further research are discussed.

Internet-based videoconferencing coder/decoders and tools for telemedicine.

Alternative videoconferencing technologies for providing telemedicine via the Internet are described. Background information about how digital video applications have been instantiated using Internet protocols is presented. Specific methods for encoding and decoding video are discussed and video applications that have been tested at the National Library of Medicine are reviewed. This article suggests that no one technology is best and that the appropriateness of a method depends on specific applications. Some technologies, however, have lower, more flexible bandwidth requirements and are more standardized, making them more practical. Still, emerging, yet-to-be-standardized applications offer new capabilities warranting further investigation.

An exploratory study of co-location as a factor in synchronous, collaborative medical informatics distance education

BackgroundThis study determined differences in learning, judgments of teaching and technology, and interaction when videoconferencing was used to deliver instruction on telemedicine to medical students in conditions where they were co-located and dispersed. A lecture on telemedicine was given by videoconference to medical students at a distant site. After a question and answer period, students were then given search problems on the topic and encouraged to collaborate. Half the students were randomly assigned to a co-located condition where they received the presentation and collaborated in a computer lab, and half were assigned to a dispersed condition where they were located in different rooms to receive the presentation and collaborate online using the videoconferencing technology. Students were observed in both conditions and they individually completed a test on presentation content and a rating scale about the quality of the teaching and the technology.FindingsThere were no differences between the two groups in the learning outcomes or judgments about the teaching and technology, with the exception that more students in the dispersed condition felt more interaction was fostered. The level and patterns of interaction were very different in the two conditions and higher for dispersed students.ConclusionsSynchronous communication at a distance via videoconference may give sufficient sense of presence that the learning experience may be similar to that in actual classrooms, even when students are far apart. The technology may channel interaction in desirable ways.

Effects of link annotations on search performance in layered and unlayered hierarchically organized information spaces

The effects of link annotations on user search performance in hypertext environments having deep (layered) and shallow link structures were investigated in this study. Four environments were tested ---- layered-annotated, layered-unannotated, shallow-annotated, and shallow-unannotated. A single document was divided into 48 sections, and layered and unlayered versions were created. Additional versions were created by adding annotations to the links in the layered and unlayered versions. Subjects were given three queries of varying difficulty and then asked to find the answers to the queries that were contained within the hypertext environment to which they were randomly assigned. Correspondence between the wording links and queries was used to define difficulty level. The results of the study confirmed previous research that shallow link structures are better than deep (layered) link structures. Annotations had virtually no effect on the search performance of the subjects. The subjects performed similarly in the annotated and unannotated environments, regardless of whether the link structures were shallow or deep. An analysis of question difficulty suggests that the wording in links has primacy over the wording in annotations in influencing user search behavior.

Interactive technology and authoring tools: A historical review and analysis

Computer systems, interactive technologies, and the software tools for authoring multimedia programs have evolved over the past several decades. The evolution of multimedia technology is discussed and current alternatives for authoring multimedia programs are described. Issues related to analyzing authoring tool requirements and selecting software are presented and trends in the evolution of authoring tools are identified. Many factors affecting the selection and use of authoring software are exogenous to the technology itself. Both technological trends and market forces must be considered.

Communication and proximity effects on outcomes attributable to sense of presence in distance bioinformatics education

BackgroundOnline learning is increasingly popular in medical education and sense of presence has been posited as a factor contributing to its success. Communication media influences on sense of presence and learning outcomes were explored in this study. Test performance and ratings of instruction and technology, factors influenced by sense of presence, are compared under four conditions involving different media and degrees of student physical presence: 1) videoconference co-located, 2) webcast co-located, 3) videoconference dispersed, and 4) webcast dispersed.MethodsEighty one first to forth year medical students heard a lecture on telemedicine and were asked to collaboratively search a telemedicine website under conditions where the lecture was delivered by videoconference or one way streaming (webcast) and where students were either co-located or dispersed. In the videoconference conditions, co-located students could use the technology to interact with the instructor and could interact with each other face to face, while the dispersed students could use the technology to interact with both the instructor and each other. In the webcast conditions, all students could use chat to communicate with the instructor or each other, although the co-located students also could interact orally. After hearing the lecture, students collaboratively searched a telemedicine website, took a test on lecture-website content and rated the instruction and the technology they used. Test scores on lecture and website content and ratings of instruction and technology for the four conditions were compared with analysis of variance and chi-square tests.ResultsThere were no significant differences in overall measures, although there were on selected ratings of instruction. Students in both webcast conditions indicated they were encouraged more to follow up on their own and felt instruction was more interactive than co-located videoconferencing students. Dispersed videoconferencing students indicated the highest levels of interaction and there was evidence they interacted more.ConclusionResults do not strongly support proximity as a sense of presence factor affecting performance and attitudes, but do suggest communication medium may affect interactivity.