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H G Schmidt

Publications and source records attributed to H G Schmidt.

At least 37 records · Page 2Linked to original sources
PubMed1998

Testing a causal model of community-based education in the Sudan.

PURPOSE: To develop and test a model of community-based education. METHOD: In 1995, after developing a hypothesized causal model for community-based education, the authors collected data for 106 students at the University of Gezira, the Sudan, who had participated over three summers in an interdisciplinary field training research and rural development course. The students rated each other on leadership, interaction with the community, subject-matter contributions, and effort. Teaching staff assessed the readiness of the community to collaborate. The students' achievement was measured by short essays measuring knowledge, supervisors' assessments of the students' performances in the community, the community's observations of the students' activities, the community's satisfaction, and a group-produced report evaluated by faculty. The effect of the students' activities on the community was measured by comparing baseline and post-intervention community health data. The students also indicated their levels of interest in the community's problems. The authors analyzed the resulting covariances using structural-equations modeling. RESULTS: After minor adaptations, the model fitted the data reasonably well. The path coefficients were quite high, particularly among the peer ratings. Leadership had a potent effect on the outcome measures, as did, to a lesser extent, the readiness of the community to collaborate with the students. CONCLUSION: This study was the first reported attempt to test a model of community-based education. Although the fit of the data to the model in the study was reasonable, further study is needed to unearth additional important elements of community-based education. This article also discusses methodologic shortcomings of the present study, such as a possible "halo effect" in the peer ratings and the retrospective nature of many of the measurements.

Ambulatory Care Facilities↗
PubMed1998

A failure to reproduce the intermediate effect in clinical case recall.

PURPOSE: To investigate the differences between experts, intermediates, and novices in diagnosing and representing clinical cases under various time constraints. METHOD: Second-, fourth-, and sixth-year medical students, and internists studied, diagnosed, and recalled four clinical cases from internal medicine. Participants were allowed to study each case for either 3 minutes, 1 minute 15 seconds, or 30 seconds. The study replicated in most ways the 1993 clinical case recall study of Schmidt and Boshuizen. RESULTS: As expected, diagnostic accuracy increased with level of expertise. However, this study failed to disclose the intermediate effect in clinical case recall that was found in the original study. Instead, a positive linear relation between expertise level and case recall was found. The discrepancy resulted from more elaborate recall by experts in the present study. Constraining processing time did not effect diagnostic accuracy, but equally affected the recall performances of the participants of all expertise levels. This contrasts with the earlier finding that experts' recall is independent of processing time. CONCLUSION: Although it is unclear why the experts' case processing was more elaborate in the present study than in the earlier study, it must be concluded that expert medical knowledge is so flexibly organized that experts can easily represent clinical cases in either the encapsulated or the elaborated mode.

Aged↗
PubMed1997

Measuring knowledge and clinical reasoning skills in a problem-based curriculum.

The purpose of this study was to investigate the validity of the Progress Test that was specially designed for measuring the growth of knowledge and clinical reasoning skills in a problem-based medical curriculum. Scores and subscores of students from the different categories of the Progress Test were compared with their scores on a Clinical Reasoning Tests. Both the Progress Test and the Clinical Reasoning Test revealed the same pattern of increasing scores over the years, and had a high intercorrelation. Further analyses revealed that the clinical sciences subscore in the progress test explained the variations in the clinical reasoning test scores. The knowledge of the behavioural sciences subscore made a small but independent contribution. The knowledge of the biomedical sciences subscore did not have this independent effect. These outcomes are discussed in this paper from the perspective of development of medical expertise research and theory. Some educational consequences are also discussed.

Curriculum↗
PubMed1996

The development of diagnostic competence: comparison of a problem-based, an integrated, and a conventional medical curriculum.

PURPOSE: To compare the diagnostic performances of students in five curriculum years educated at schools with problem-based, integrative, or conventional medical curricula. METHOD: Data were analyzed in 1994 for 612 students in their second, third, or fourth (preclinical) or fifth or sixth (clinical) years at three Dutch medical schools with problem-based, integrative, or conventional curricula. The students gave differential diagnoses for 30 case histories that were epidemiologically representative of Dutch society and covered all organ systems. The numbers of accurate diagnostic hypotheses were tallied for each of the groups involved. The data were analyzed using analysis of variance and post-hoc Newman-Keuls tests. RESULTS: Overall, the students trained within the problem-based framework and the students trained within the integrated curriculum made more accurate diagnoses than the students trained within the conventional curriculum. No overall differences were found between the students in the problem-based and integrated curricula, although the second- and third-year students from the latter performed better than the second- and third-year students from both other schools. CONCLUSION: Integration between basic and clinical sciences and an emphasis on patient problems may be the critical factors that determine superior diagnostic performance rather than whether a curriculum is self- or teacher-directed. Problem-based learning seems to live up to its expectations, but so does the integrated approach to medical education. In addition, the procedure for measuring diagnostic performance appears to be valid and to provide a simple means of measuring curriculum effects. It remains to be seen whether the findings would be replicated when students are allowed to freely gather data in open interaction with patients rather than respond to written presentations of cases.

Aged↗
PubMed1996

Effects of tutor expertise on student performance in relation to prior knowledge and level of curricular structure.

PURPOSE: To test whether there are effects of tutor expertise on student performance under conditions of curricular materials that have low or high levels of structure and that are poorly or well matched to students' levels of prior knowledge. METHOD: The study was conducted in 1994-95 at the medical school of the University of Limburg. The data set used for analysis included 135 tutorial groups (with ten to 12 students per group), 119 tutors (each running only one group per unit), and 15 units in four curriculum years. The analysis was conducted at the level of tutorial groups since a tutor's level of expertise might differ for distinct units. Tutors were asked to judge their levels of expertise related to the cases discussed, based on which a distinction was made between expert and non-expert tutors. The degrees of structure of curricular materials and students' levels of prior knowledge were rated by the students. Using analyses of variance, students' scores on end-of-unit tests (each with about 150 true-false items) were compared for groups led by expert and non-expert tutors under conditions of low and high levels of structure and low and high levels of prior knowledge. RESULTS: No difference was found between the test scores of groups led by expert and non-expert tutors. The interaction effects between expertise and structure and expertise and prior knowledge also turned out to be not statistically significant. CONCLUSION: The results suggest that expert tutors do not compensate for lack of curricular structure or students' lack of prior knowledge. This finding is not consistent with that of a recent study that expert tutors do compensate for lack of structure and lack of prior knowledge. This discrepancy may be accounted for by a much smaller range within which the structuredness of the curriculum and students' levels of prior knowledge varied in the present study compared with the previous study. An implication might be that faculty should put their efforts into designing structured curricula that are well matched to students' levels of prior knowledge instead of selecting hyper-expert tutors.

Curriculum↗
PubMed1996

The influence of medical expertise, case typicality, and illness script component on case processing and disease probability estimates.

The present study investigated the influence of medical expertise, case typicality, and illness script component (enabling conditions vs. consequences) on the speed of case information processing and subjective disease probabilities. It was hypothesized that expert subjects would process case information faster than nonexpert subjects, that typical information would be processed faster than atypical information, and that an interaction would be found between expertise level, typicality, and illness script: Experts were expected to be sensitive to typicality of both illness script components, while advanced students would be sensitive only to typicality of consequences. This sensitivity would also be reflected in assigned probability estimates. The data supported the predictions concerning the effects of expertise level and typicality; it was also found that expert physicians are particularly sensitive to a combination of prototypical enabling conditions and prototypical consequences. Implications of these results for the illness script theory are discussed.

Child↗
PubMed1996

Ultrastructural aspects of the neuroendocrine complex in the stomach in patients with either pernicious anemia or the Zollinger-Ellison syndrome.

The neuroendocrine complex of the gastrointestinal tract is defined as the presence of neuroendocrine cells in the lamina propria and in direct contact with nerve fibres of Meissner's plexus. The entire complex is separated from the interstitium by a basement membrane. To date, only a few studies have been published on the neuroendocrine complex. In this prospective electron microscopic study, we investigated the neuroendocrine complex of the stomach in 21 patients with pernicious anemia, and in eight patients with the Zollinger-Ellison syndrome. For each patient, six step biopsies obtained from the stomach at endoscopy were investigated. 16 out of the 21 patients with pernicious anemia, and four of the eight patients with the Zollinger-Ellison syndrome were found to have neuroendocrine complexes in the gastric mucosa. In patients with pernicious anemia who had neuroendocrine complexes more neuroendocrine complex-positive biopsies were found, on average, per patient, and more and larger neuroendocrine complexes, on average, per biopsy, than was the case in patients with the Zollinger-Ellison syndrome. These results show that in the gastric mucosa of patients with pernicious anemia, more marked proliferation of neuroendocrine complexes occur than in patients with Zollinger-Ellison syndrome.

Adult↗
PubMed1995

[Nerve-neuroendocrine complexes in stomach mucosa in Zollinger-Ellison syndrome].

Nerve fibre-neuroendocrine cell complexes (NF-NEC-C's) are neuroendocrine cells located in the lamina propria of the gastro-intestinal tract directly connected with nerve fibres of Meissner's plexus. We report on a patient with sporadic Zollinger-Ellison syndrome (ZES) with electron microscopically demonstrated multiple NF-NEC-C's in non-antral gastric mucosa. It is suspected that in ZES the hypergastrinaemia may represent a trophic stimulus for the proliferation of NF-NEC-C's in the gastric mucosa.

Adult↗
PubMed1995

What makes a tutor effective? A structural-equations modeling approach to learning in problem-based curricula.

PURPOSE: To test and further develop a causal model of the influence of tutor behaviors on student achievement and interest in the context of problem-based learning. METHOD: Data from 524 tutorial groups involving students participating in the four-year undergraduate health sciences curriculum at the University of Limburg in 1992-93 were analyzed. The tutorial groups were guided by 261 tutors. Overall, 3,792 data records were studied, with each student participating in an average of 2.3 groups. Correlations among tutors' social-congruence, expertise-use, and cognitive-congruence behaviors, small-group functioning, and student' self-study time, intrinsic interest in subject matter, and level of achievement were analyzed using structural-equations modeling. This statistical technique allows the investigator to test causal hypotheses on correlational data by comparing the structure of data with a theoretical model. RESULTS: After minor adaptations, the hypothesized causal model of the effective tutor fitted the data extremely will. Each tutor's level of expertise use and social congruence not only directly affected his or her level of cognitive congruence but also affected other elements of the model. Level of social congruence influenced group functioning in a direct fashion, while expertise use had a slightly negative effect on the students' level of self-study time and a slightly positive effect on level of achievement. As hypothesized, the level of cognitive congruence influenced tutorial-group functioning. Level of group functioning affected self-study time and intrinsic interest. Finally, time spent on self-study influenced level of achievement. CONCLUSION: The results suggest that subject-matter expertise; a commitment to students' learning and their lives in a personal, authentic way; and the ability to express oneself in the language used by the student are all determinants of learning in problem-based curricula. The theory of the effective tutor, presented in this article, merges two different perspectives prevalent in the literature. One perspective emphasizes the personal qualities of the tutor: his or her ability to communicate with students in an informal way, coupled with an empathic attitude that enables the tutor to encourage student learning by creating an atmosphere in which open exchange of ideas is facilitated. The other stresses the tutor's subject-matter knowledge as a determinant of learning. The data presented in this article suggest that what is needed, really, is much of both.

Achievement↗
PubMed1995

[Splenic vein aneurysm: diagnosis with color-coded duplex ultrasound].

This is a report on a 67-year-old woman who was admitted to our department with a suspected pseudocyst of the pancreas as diagnosed by ultrasonography performed elsewhere. A percutaneous US study revealed an echo-free space-consuming process measuring 3 cm in diameter and located cranially to the pancreas. On the basis of colour Doppler sonography, a splenic vein aneurysm was diagnosed. An endosonographic examination clearly visualized the aneurysm. Colour Doppler sonographic examination is a valuable diagnostic procedure for the differential diagnosis of "cystic" space-consuming processes in the region of the pancreas.

Aged↗
PubMed1995

[Treatment of severe concomitant injuries in severely burned patients].

Over a period of almost 6 years, 18 out of 320 burn patients treated in the burn centre had sustained additional severe trauma; for the most part the trauma was due to a motor vehicle accident or a fall. The risk of overlooking such additional injuries can be minimized by systematic examination and a team approach, the same as in normal multiple-trauma patients. Apart from the burn, life-threatening complications such as intra-abdominal bleeding or haemopneumothoracic injuries are to be treated immediately. In order to facilitate appropriate burn wound care and optimize mobilization, early internal or external fixation of unstable orthopaedic injuries should be performed as soon as possible. In our experience, operations carried out within 48 h after the injury have neither led to complications in wound healing nor to osteomyelitis.

Adolescent↗
PubMed1995

[Development and characterization of an absorbable temporary wound dressing].

Most of the temporary dressings used in the treatment of burns do not meet the objectives of a skin substitute concerning application, safety and comfort. Removal is often painful and traumatic and increases the risk of infection. Biodegradable polymers of lactic and caproic acid were developed as part of a research programme (BMFT/FRG 01 KG 8809/7), and chemical and physical properties were investigated. Films made of the copolymer material were characterized by structure, transparency, permeability, tensile strength, flexibility and degradation. The transparent films appeared increasingly opaque during hydrolysis. The water vapour permeance could be varied between 40 and 250 (40-136) ml/m2 per h (according to the method of measurement). The mechanical properties are characterized by a maximum elongation of > 2000% at 37 degrees C and a very low elastically modulus. When the results were compared with those of three established film dressings, no restriction was found in the aptitude of the material as a wound dressing.

Animals↗
PubMed1994

Resolving inconsistencies in tutor expertise research: does lack of structure cause students to seek tutor guidance?

PURPOSE: To investigate under what conditions tutors' subject-matter expertise influences student achievement. METHOD: Data were analyzed from 1,800 University of Limburg Faculty of Health Sciences students who in 1989-90 participated in tutorial groups led by content-expert staff tutors, non-expert staff tutors, or student tutors. Each student participated in an average of 4.1 tutorial groups. Overall, 4,111 data records were available for analysis. The basic analyses were of (1) students' achievement scores as a function of tutors' levels of subject-matter expertise and students' prior knowledge; (2) students' achievement scores as a function of tutors' levels of subject-matter expertise and educational units' levels of structure; and (3) differences in achievement between students guided by tutors of different levels of expertise in either high- or low-structure units. Statistical methods included analyses of variance. RESULTS: The level of subject-matter expertise of tutors had a positive influence on student achievement. Similar results were found for the students' prior knowledge and the levels of structure of the units; the more prior knowledge students had, the better were their performances on the end-of-unit test; and the higher the level of structure of the unit, the better the achievement. More important, interactions were found between tutor expertise on the one hand and prior knowledge and unit structure on the other, tutor expertise being mainly important if the unit was poorly structured or students reported lack of prior knowledge. CONCLUSION: The results suggest that students need a minimum level of structure in order to profit from problem-based instruction. This structure can be internally provided through prior knowledge available for understanding the new subjects, or offered by the environment in the form of cues of what is relevant and what should be the focus of the activities. If prior knowledge falls short, or if the environment lacks structure, students will turn to their tutors for help and direction. Under those conditions, students who are guided by a subject-matter expert tutor may benefit more than students guided by a non-expert staff tutor or by a student tutor. These findings may explain the widely divergent results of tutor-expertise research.

Achievement↗
PubMed1994

What drives the student in problem-based learning?

In problem-based learning, the development of self-directed learning skills is encouraged through confronting students with (professional) problems. However, several other elements of a problem-based curriculum, such as general teaching objectives, lectures and tutors, may have an impact on students' actual learning activities. The present study focuses on the extent to which various elements of a problem-based curriculum influence students' decisions on what to study. First, interviews were conducted to obtain qualitative data about what actually takes place when students initiate learning activities during self-study. Based on the findings of these interviews, a questionnaire was developed, consisting of statements describing elements of the learning process and their influence on student learning. Elements included in the questionnaire were: the discussion in the tutorial group, content tested, course objectives, lectures, the tutor and reference literature. The students reported that all these elements may have an impact on decisions on what to study. Moreover, first-year students tend to rely more on the literature cited in the references list and content covered in lectures and tests than students in the other three curriculum years. In general, the influence of these elements showed a decrease over the four curriculum years. The influence of the discussion in the tutorial group, on the contrary, tended to increase over the four curriculum years. These findings suggest that students in a problem-based curriculum become more accomplished self-directed learners over the four curriculum years, even although they are provided with many clues which may play a role in their decisions on what to study.

Decision Making↗
PubMed1994

A rating scale for tutor evaluation in a problem-based curriculum: validity and reliability.

An instrument has been developed to assess tutor performance in problem-based tutorial groups. This tutor evaluation questionnaire consists of 13 statements reflecting the tutor's behaviour. The statements are based on a description of the tasks set for the tutor. This study reports results on the validity and reliability of the instrument. Confirmatory factor analysis showed that a three-factor model fitted the data reasonably well. The three factors are: (1) guiding students through the learning process, (2) content knowledge input, and (3) commitment to the group's learning. Generalizability studies indicated that the rating scales provide reliable information with student responses of existing tutorial group sizes. It is concluded that the tutor evaluation questionnaire is a fairly valid and reliable instrument that can be used in staff development programmes.

Curriculum↗
PubMed1994

[Change in the treatment method of infected pseudarthrosis with bone loss of the tibia].

AIM OF INVESTIGATION: The treatment of nonunions complicated by infection and bone loss is divided into two stages. Having calmed down the infection by stabilizing, removal of infected and necrotic tissue and local antibacterial measures, the bone loss has to be filled up. Bridging the gap by means of autogenous cancellous bone grafting is complicated by a high rate of refractures depending on the length of bone loss. Therefore after changing the method and using the Ilizarov procedure it is of interest, whether this method offers advantages. Our experience is to be reported and discussed. METHODS: According to the clinical course two groups of patients with nonunions of the tibia complicated by infection and bone loss were compared. 25 previously evaluated patients of the years 1980/81 whose tibial bone loss was bridged by cancellous bone grafting (1st group) were compared with 16 patients who were treated by the Ilizarov method from May 1990 to October 1993 (2nd group). The average age was nearly the same (32.6/32.9 years). In the first group the average of bone loss measured 4 cm, in the second 7.8 cm. The number of initial operations to eliminate infection and the duration of fixator application from the beginning of bridging bone loss were compared as well as early and late complications, especially the rate of refracture and reinfection. RESULTS: 1.2 operations were needed to eliminate infection in the first group, in the second only one was necessary. The handling of the Ilizarov device is more difficult and needs training. The higher rate of early complications at the beginning decreased with increasing experience. The average of fixation time could be reduced by about ten days per cm of bone loss using the Ilizarov technique. By segmental transport new cortical bone is generated which surpasses cancellous bone grafting in regard to stability. This seems to be an important reason that refracture did not occur in the second group. Furthermore, reinfection could be avoided up to now obviously due to sufficient segmental resection of infected and necrotic tissue. Limited stores of autogenous cancellous bone are not to be feared. The total number of operations can be reduced. At the docking side early single cancellous bone grafting is recommended.

Adolescent↗
PubMed1993

Problem effectiveness in a course using problem-based learning.

BACKGROUND: Problem-based learning (PBL) emphasizes active generation of learning issues by students. Both students and teachers, however, tend to worry that not all important knowledge will be acquired. To explore this question, problem effectiveness (i.e., for each problem, the degree of correspondence between student-generated learning issues and present faculty objectives) was examined in three interdependent studies. METHOD: The three studies used the same participants: about 120 second-year students and 12 faculty tutors in a six-week course on normal pregnancy, delivery, and child development at the medical school of the University of Limburg in The Netherlands, 1990-91. The participants were randomly assigned to 12 tutorial groups that were each given the same 12 problems; the problems were based on 51 faculty objectives; the tutors were asked to record all learning issues generated by their groups. Study 1 addressed this question: To what degree are faculty objectives reflected by student-generated learning issues? Study 2: To what extent do students miss certain objectives, and are these objectives classifiable? Study 3: Do students generate learning issues not expected by the faculty, and are these issues relevant to course content, and finally, why do students generate these issues? To help answer these questions, the studies employed expert raters and a teacher familiar with the course content. RESULTS: Study 1: For the set of 12 problems, the average overlap between learning issues and faculty objectives was 64.2% with the percentages for individual problems ranging from 27.7% to 100%. Study 2: Of the 51 objectives, 30 were not identified by at least one tutorial group; these objectives were grouped into three categories; on average, each group failed to identify 7.4 objectives (15%). Study 3: Of 520 learning issues, 32 (6%) were unexpected; 15 of these were judged to be at least fairly relevant to course content; they were grouped into four categories. CONCLUSIONS: The students' learning activities covered an average of 64% of the intended course content; in addition, the students generated learning issues not expected by the faculty, and half of these issues were judged relevant to the course content. Thus, PBL seems to permit students to adapt learning activities to their own needs and interests.

Clinical Competence↗