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Understanding high-level performance requires effective methods of studying expertise and expert performers. Representative tasks that capture the key components of expertise can be identified, allowing expert performance to be studied under controlled conditions. Well-designed representative tasks can allow researchers to elucidate the underlying mechanisms for superior performance, stratify performers based on skill, and uncover the developmental steps taken by those performers to reach their current levels of performance. In the present chapter, the authors first provide a general overview of the concepts of representative tasks and simulated task environments. The authors then describe in more detail how representative tasks and simulated task environments can be used to achieve the twin goals of understanding expert performance and developing training on the basis of expert performers. The authors then present examples of recent research involving representative tasks. The chapter concludes with the authors presenting future directions for the use of representative tasks in research and practice.

Backgrounds With the increasing use of simulation in nursing education and a growing acceptance of simulation as a component of student's clinical experiences, there is a need to provide evidence of a relationship between knowledge, performance in simulated task environments, and actual clinical performance. Methods This study used a pre/post test design to examine the relationship between standardized test scores and performance in real-time and simulated critical care settings. Performance in a simulated task environment and scores on standardized tests were examined before and after a 4-week critical care experience in a group of senior nursing students. Results Findings from the study demonstrate statistically significant relationships among the three variables. Conclusions Findings from the study provide evidence for the effectiveness of simulated scenarios as a means to assess clinical performance and to differentiate between high- and low-performing students.

Research on decision-making under stress has mainly involved laboratory-based studies with few contextual descriptions of decision-making under stress in the natural ecology. We examined how police officers prepared for, coped with and made decisions under threat-of-death stress during real events. A delayed retrospective report method was used to elicit skilled police officers' thoughts and feelings during attempts to resolve such events. Reports were analysed to identify experiences of stress and coping, and thought processes underpinning decision-making during the event. Officers experienced a wide range of events, coped with stress predominantly via problem-focused strategies, and adapted their decision-making under stress based on the available context. Future officer training should involve a greater variety of training scenarios than is involved in current training, and expose trainees to the possible variants of each situation to foster better situational representation and, thus, a more reliable and adaptive mental model for use in decision-making. Practitioner Summary: This study concerns decision-making and coping strategies used by skilled police officers during real threat-of-death situations. Officers' decision-making strategies differed according to the complexity of the situation and they coped with the stress of these situations via attempts to resolve the situations (e.g. by planning responses) and, to a lesser extent, via attempts to deal with their emotions.

A better understanding of the factors influencing medical team performance and accounting for expert medical team performance should benefit medical practice. Therefore, the aim here is to highlight key issues with using deliberate practice to improve medical team performance, especially given the success of deliberate practice for developing individual expert performance in medicine and other domains. Highlighting these issues will inform the development of training for medical teams. The authors first describe team coordination and its critical role in medical teams. Presented next are the cognitive mechanisms that allow expert performers to accurately interpret the current situation via the creation of an accurate mental "model" of the current situation, known as a situation model. Following this, the authors propose that effective team performance depends at least in part on team members having similar models of the situation, known as a shared situation model. The authors then propose guiding principles for implementing team deliberate practice in medicine and describe how team deliberate practice can be used in an attempt to reduce barriers inherent in medical teams to the development of shared situation models. The paper concludes with considerations of limitations, and future research directions, concerning the implementation of team deliberate practice within medicine.

Background Falls represent a significant threat to patient safety for hospitalized patients throughout the world. Little is known, however, regarding nurses' immediate responses to the discovery of a fallen patient. Objectives The objective of this study was to perform an experimental examination of experienced and novice nurses' reaction to the discovery of a fallen patient who has sustained a closed head injury. Design The study was based upon the expert performance approach, which utilizes a mixed methods approach to determining performance characteristics of individuals performing in a variety of domains. Setting The study was accomplished using a simulated task environment developed specifically for research concerning the performance of health professionals. Participants The study included 12 experienced and 10 novice nurses, all of whom were currently employed in critical care settings. Methods The study used directly observed performance, which was quantified through the use of direct coding of clinical behaviors and the analysis of verbal reports of thought. Results The data indicate that experienced participants were not only more likely to call for help but that they were more likely to precede this action by checking for responsiveness, and then, after calling for help, establish the effectiveness of the patient's airway, breathing and circulation. These data confirmed that experienced participants were more likely to engage in the appropriate sequence of actions when faced with this unexpected and highly stressful situation. Conclusions Novice nurses' superficial assessment of the situation and subsequent failure to react properly implied an overall pattern of superior performance by the experienced nurses. The results indicated that, compared with novice nurses, experienced nurses are more likely to initiate standard treatment protocols in situations such as the one reported in this study.

The recognition-primed decision (RPD) model and Take the First (TTF) heuristic assert that successful and experienced decision makers typically generate relatively few options, and generate a satisficing, or the best, option first. Moreover, the TTF heuristic suggests that as more options are generated the likelihood that the best option will be selected is reduced. An alternative proposal suggests that the ability to anticipate the outcome of a situation is actually positively related to the number of options generated. To test these opposing claims we compared high and low performing critical-care nurses on three simulated critical care scenarios and measured their option generation behaviors and the courses of action pursued. Consistent with RPD and TTF, the data suggest that high performers generate fewer options than low performers during situational assessment. However, counter to RPD and TTF, the current data suggest that the selection of options generated later in the process may actually facilitate better outcomes. Implications for the design of instruction and training materials are discussed.

In military and sports tasks, individuals are often required to perform in a complex and dynamic environment and obtain a tactical advantage over an opponent even when only partial or incomplete information is available. Successful performance in both domains is typically dependent upon the ability to work both independently and as a team in an effective manner by combining perceptual, cognitive, motor, and social skills, often under stressful circumstances. Despite these similarities, and the extensive literature bases amassed on training in each field, there has been little, if any, cross-fertilization or collaboration. We offer a synopsis of perceptual-cognitive and decision skills training research from the fields of sport psychology, expert performance, human factors, and military psychology with a view toward highlighting commonalities and differences in approach to training. Attention is drawn to the experimental designs and interventions employed, as well as methodological shortcomings and how these have been addressed. In addition, we highlight the differences in how training recommendations have been derived, discuss questions that have been raised in developing and validating training programs, and, in particular, emphasize the need for evidence-based practice. Our aim is to offer conclusions from the sport psychology literature that can inform the design, structure, content, and implementation of future military decision training.

Contains fulltext : 64508.pdf (Publisher’s version ) (Closed access) Two studies compared Dutch college students' individuation of women and men. Participants read trait descriptions and formed impressions of male and female targets. They then attempted to recall which traits had described each target. Consistent with the status hypothesis, participants viewed men as higher status and made fewer recall errors overall for male targets, indicating greater individuation of men. However, this effect was moderated by attitudes. Participants with more traditional attitudes toward women's roles individuated men more than women, whereas those with less traditional views individuated women and men equally. 6 p.

Background: Medication errors are costly in both human and financial loss. Interpretations of prescription instructions have been found to vary considerably, including discrepancies between patients and prescribing physicians. Objective: Identify discrepancies in interpretation of prescription instructions between healthcare consumers, nurses, and physicians Method: Research Design: Cross-sectional study; Setting: Large university, 2 hospitals and various clinics in Mississippi and Florida; Participants: 74 young healthcare consumers, 34 RNs, and 36 physicians; Measures: Questionnaires asking for interpretations (i.e., what times would/should you take the drug) for various prescription instructions were provided to healthcare consumers, nurses, and physicians. Results: There was considerable within-group variability in the interpretation of prescription instructions by all groups including physicians. Moreover, physicians, nurses, and healthcare consumers exhibited between group variability in their interpretation of prescription instructions. None of the instructions were uniformly interpreted and a fair number of consumer and nurse interpretations resulted in potentially unsafe schedules of drug administration. Some physicians and nurses also apparently lacked awareness of the potential for interpretation variability. Conclusions: Because two healthcare providers can have different intentions for identical instructions, an awareness and subsequent education of potential sources of misinterpretation is vital. The present results indicate a need to identify and explore within-group variability of intent among physicians and other healthcare providers.

The aim of this article was to provide a response that supports and extends Schiavenato’s call for a theoretically guided approach to simulation use in nursing education. We propose that a theoretical framework for simulation in nursing must first include, as a basis, a theoretical understanding of human performance and how it is enhanced. This understanding will, in turn, allow theorists to provide a framework regarding the utility, application, and design of the training environment, including internal and external validity. The expert performance approach, a technique that recently has been termed Expert-Performance-based Training (ExPerT), is introduced as a guiding framework for addressing these training needs. We also describe how the theory of deliberate practice within the framework of ExPerT can be useful for developing effective training methods in health care domains and highlight examples of how deliberate practice has been successfully applied to the training of psychomotor and cognitive skills.

SUMMARY Significant real estate activity by Vietnamese households in Adelaide did not occur until 1979, and since then the groups buying activity has been heavily concentrated in the northwest region of the metropolitan area. Therefore, the median housing price paid by Vietnamese buyers has not kept pace with the median price paid by all buyers. Concentration also causes Vietnamese buyers to be disproportionately active in the middle‐to‐lower end of the market, within which there has been a strong preference for rural properties and for houses rather than home units and maisonettes. Amongst Vietnamese buyers who subsequently sell their properties, the majority have not re‐entered the market and their capital gain from ownership has been marginal.

A consistent, albeit fragile, finding over the last couple of decades has been that verbalization of hard-to-verbalize stimuli, such as faces, interferes with subsequent recognition of the described target stimulus. We sought to elicit a similar phenomenon whereby visualization interferes with verbal recognition—that is, visual overshadowing. We randomly assigned participants ( n = 180) to either concrete (easy to visualize) or abstract (difficult to visualize) sentence conditions. Following presentation, participants were asked to verbalize the sentence, visualize the sentence, or work on a filler task. As predicted, visualization of an abstract verbal stimulus resulted in significantly lower recognition accuracy; unexpectedly, however, so did verbalization. The findings are discussed within the framework of fuzzy-trace theory.

In April 1986 housing finance allocation procedures were deregulated. The impact of this decision on levels of finance borrowed by households was assessed for 2562 buyers of houses and home units in the Adelaide Statistical Division during May and June 1986. Sales price and mortgage data suggest two tendencies influencing the relationship between price and mortgage. Firstly, low price purchasers have small deposits and borrow heavily to effect their purchase. Secondly, high price buyers, with large deposits, are nevertheless taking out large loans to finance housing. Levels of gearing show market socio-economic bias, low cost buyers being more likely to be overcommitted.

In recent models of decision-making, cognitive scientists have examined the relationship between option generation and successful performance. These models suggest that those who are successful at decision-making generate few courses of action and typically choose the first, often best, option. Scientists working in the area of expert performance, on the other hand, have demonstrated that the ability to generate and prioritize task-relevant options during situation assessment is associated with successful performance. In the current study, we measured law enforcement officers’ performance and thinking in a simulated task environment to examine the option generation strategies used during decision-making in a complex domain. The number of options generated during assessment (i.e., making decisions about events in the environment) and intervention (i.e., making decisions about personal courses of action) phases of decision-making interact to produce a successful outcome. The data are explained with respect to the development of a situational representation and long-term working memory skills capable of supporting both option generation processes.

The present study investigated whether a differential number of perceived subgroups for men and women mediated the previous finding that men and women with more traditional attitudes concerning women's roles individuate men more than women, whereas individuals with less traditional attitudes better individuate women (Stewart, Vassar, Sanchez, & David, 2000). Participants were asked to recall traits of 2 male and 2 female targets described to them. Comparison of memory errors for male vs female targets indicated relative individuation of men and women. Participants also generated subgroups of men and women and indicated their familiarity with these groups. As predicted, relative number of subgroups but not differential familiarity mediated the relationship between attitudes and relative individuation of men and women. More complex representations of women are proposed to facilitate organization of information about new members of this group.

Enzyme histochemistry has revealed that encapsulation reactions surrounding larvae of the nematode Angiostrongylus cantonensis 4 wk after infection of the gastropod Biomphalaria glabrata are the sites of highly localized acid phosphatase and nonspecific esterase activities. Lesser amounts of alkaline phosphatase and β-glucuronidase activities also occur within such capsules, but aminopeptidase activity cannot be demonstrated. In addition, it has been ascertained that acid phosphatase activity gradually increases as the encapsulation reaction progresses during the first to the fourth week postinfection.

Nearly 2% of the specimens of the mudflat snail, Nassarius obsoletus, collected during June and July of 1972 from southern New Jersey has been found to be parasitized by sporocysts of the trematode Zoogonus rubellus. This parasite causes what is essentially total parasitic castration of this estuarine mollusc. The gonads of the hosts are almost completely absent and in their place, large, vacuolated Leydig cells fill the spaces not occupied by parasites on the periphery of the digestive glands. There is no doubt that the snails would have been sexually mature at the time of collection since all noninfected specimens included either fully developed ova or sperm. It is postulated that the destruction of the host's gonad has resulted from what is being designated as “direct chemical castration,” i.e., the sex cells are destroyed by some substance secreted by the parasite rather than as the result of direct mechanical damage. Since N. obsoletus also serves as the intermediate host for the avian schistosome Austrobilharzia variglandis, the etiologic agent for “swimmer's itch” in the same area, the potential importance of Z. rubellus as a biological control agent against A. variglandis is raised.

The most common route of infection of Biomphalaria glabrata experimentally exposed to first-stage larvae of Angiostrongylus cantonensis is via penetration of the gastric and prointestinal walls after ingestion. Subsequently, most parasites migrate through the kidney and rectal ridge to the mantle collar and head-foot of the gastropod at which sites they become lodged. Nematodes are encapsulated in B. glabrata beginning by 24/2-48 h post-infection. Encapsulation occurs as a two-phase process involving (1) initial infiltration and aggregation of basophilic hemolymph cells around the parasite and (2) subsequent transformation of such cellular aggregates into more fibrous-appearing nodules. The small number of parasites which localize in such tissues as the rectal ridge, kidney, or vascular connective tissue near the gonad are similarly encapsulated.

The tegumentary ultrastructure of Leucochloridiomorpha constantiae metacercariae and adults has been described. A filamentous glycocalyx invests the tegument of metacercariae and large numbers of biconcave, disk-shaped secretion vesicles are found in its outer zone, cytoplasmic bridges and cytons. Mitochondria within the outer tegumentary zone of metacercariae are restricted to its basal half. The transformation of metacercariae to adults involves the loss of the glycocalyx, a decrease in the number of disk-shaped secretion vesicles, a more uniform distribution of mitochondria through the outer tegumentary zone, an apparent degeneration of cytons, a thinning of the fibrous basal lamina and a decrease in the number of visible cytoplasmic bridges traversing it. The significance of these events for a metacercaria which does not encyst within the molluscan host is discussed. In addition, crystalline, spine-like inclusions in the outer tegumentary zone of adult L. constantiae are described and their possible function discussed.

A review of literature dealing with neurosecretion in the Platyhelminthes is presented and presumptive neurosecretory cells associated with the cerebral ganglia and longitudinal nerve cords of Leucochloridiomorpha constantiae metacercariae and adults are described. Both the mean number of aldehyde-fuchsin stained presumptive neurosecretory cells and the intensity of staining are less in adults than in metacercariae. This suggests that maturation in this trematode may be directly or indirectly associated with a reduction in neurosecretion as in nereid annelids. Results of cytochemical studies indicate the neurosecretory product contains a glycoprotein.

Monometacercarial infections of the trematode, Leucochloridiomorpha constantiae, in the bursa of Fabricius of the domestic chick produce adults capable of self-insemination and eggs containing miracidia. Observations on worm pairing, cross-copulation, and the absence of autocopulation suggest cross-insemination as the prevalent mode of reproduction in double-worm infections. Eggs containing miracidia were first seen in flukes from 7-day-old doubleand 9-day-old single-infections and the number of such eggs was markedly reduced in the latter. Experiments reviewed by Bacha (1966), Nollen (1968), and Fan and Chiang (1970) indicate that certain species of hermaphroditic digenetic trematodes are capable of producing eggs containing miracidia in situations that preclude cross-insemination, presumably by self-fertilization or parthenogenesis. Using autoradiographic techniques Nollen (1968) demonstrated that although Philophthalmus megalurus adults are capable of self-insemination, the usual mode of reproduction is cross-insemination when more than one worm is present. The purpose of this study was to determine if Leucochloridiomorpha constantiae adults are capable of self-insemination and the production of eggs containing miracidia in situations that preclude cross-insemination, and to examine reproduction in flukes permitted to cross-inseminate. Results of observations on reproduction in singleand double-worm infections of L. constantiae in the domestic chick are presented herein. MATERIALS AND METHODS Metacercariae were dissected from uteri of naturally infected Campeloma decisum snails (Mueller, 1935; Allison, 1943) collected in Jenning's Lake, Camden County, New Jersey. Fresh larvae or those stored for up to 2 days in Ringer's at 10 C with no apparent decrease in viability were used. The "cloacal drop" method of Allison (1943) was used to expose 121 1to 2-day-old domestic chicks Received for publication 9 February 1971. * Supported in part by a research grant from The Lafayette College Committee on Advanced Study and Research. t Present address: Institute for Pathobiology, Lehigh University, Bethlehem, Pennsylvania 18015. anesthetized with Equi-Thesin (Fried and Berry, 1961) to either 1 or 2 metacercariae per chick (Tables I, II). Chicks were necropsied 7 to 10 days postexposure and the bursa of Fabricius was removed and inverted in Ringer's. Following in situ observations each worm was examined live under light coverslip pressure within 1 to 2 min of its removal. To assess development, each worm's uterus was teased in 1 to 2 ml of Ringer's and 100 to 200 eggs per worm examined at random. Fully developed eggs, i.e., those containing a pear-shaped miracidium (Allison, 1943) were scored and tabulated in percentage per worm (Tables I, II).

Leucochloridiomorpha constantiae metacercariae grew, attained sexual maturity, and produced eggs containing fully developed miracidia in the bursa of Fabricius of the domestic chick and on the chick chorioallantois. Chicks cloacally exposed to metacercariae remained infected up to 8 weeks although the bursa was still present after 12 and 13 weeks. Following cloacal exposure with metacercariae, a low percentage of worms was recovered from the rectum of chemically bursectomized chicks. Body and testicular growth were greater in chickthan in chorioallantoic worms although as development progressed both demonstrated similar testicular-to-body size ratios. Daily development in the chick and on the chorioallantois has been described through sexual maturity. Chorioallantoic worms became ovigerous and contained eggs with miracidia later than chick worms and frequently produced aberrant eggs and abnormal stages of spermatogenesis, suggesting the chick is a more favorable site for development. Leucochloridiomorpha constantiae (Mueller, 1935) parasitizes the bursa of Fabricius of the black duck, Anas rubripes, and has been maintained in the small intestine of raccoons, and in the bursa of domestic ducks and chicks in the laboratory (Gower, 1938; Allison, 1943; Fried and Harris, 1971). Free metacercariae obtained from the uterus of naturally infected Campeloma decisum snails are suitable for experimental studies since they are easily maintained in the laboratory, infect domestic chicks and the chick chorioallantois, and become ovigerous in these sites within 3 or 4 days. This paper reports studies on infection, growth, and development of this trematode in the chick and on the chorioallantois. MATERIALS AND METHODS As described previously (Fried and Harris, 1971), metacercariae obtained from C. decisum snails were used to infect 1and 2-day-old domestic chicks cloacally and worms were recovered from the bursa. Chicks exposed to 4 to 6 metacercariae were necropsied at intervals from 5 min to 13 weeks to determine infectivity. Growth and development studies were made on worms reReceived for publication 7 September 1971. * Supported in part by a research grant from the Lafayette College Committee on Advanced Study and Research. t Present address: Institute for Pathobiology, Lehigh University, Bethlehem, Pennsylvania 18015. + Present address: Cornell University Medical College, New York, New York 10021. covered daily from 1 to 7 days following exposure of chicks to either 3 or 5 metacercariae. Infectivity was also determined for 14 1and 2-day-old chicks exposed orally to a total of 116 metacercariae (5, 6, or 10 each) in Ringer's and necropsied 3 days later. Chemically bursectomized chicks were hatched from eggs which, on the 3rd day of incubation, had been dipped, pointed end down, into cold 3% testosterone propionate (Nutritional Biochemicals Co., Cleveland, Ohio) in 95% ethanol to a depth of approximately 40 mm for 5 sec (Glick and Sadler, 1961). Infectivity was determined for 14 1and 2-day-old bursectomized chicks exposed cloacally to a total of 94 metacercariae (3 to 17 each) and necropsied at intervals from 4 hr to 3 days. Metacercariae transferred through 3 changes of sterile Ringer's were placed on chorioallantoic membranes of 8to 10-day-old fertile white leghorn eggs (Zwilling, 1959). Eggs which received 5 or 6 metacercariae each were incubated at 37.5 C and flukes were recovered daily from 1 to 8 days postinoculation. Metacercariae, chick-, and chorioallantoic worms were pipetted into hot AFA (Fried, 1962a), stained in Gower's (1939) carmine, cleared in terpineol, mounted in Permount, and used for growth measurements. Worms stained intravitally with neutral red were examined under light coverslip pressure to assess development and observations were also made on Bouin's and Caroy fixed paraffin sections stained with either Harris' hematoxylin or Heidenhain's iron alum hematoxylin and eosin.