The Effect of Expertise on the Quality of Appraisal Services

This article examines the quality of appraisals as a function of expertise. In paraticular, we compare novices (beginning real estate students) to experts (practicing certified and/or designated appraisers) on three performance criteria. First, we examine differences in the values that these two groups attach to various property features. Second, we investigate the variation between their final market value estimates. The last task studied is whether appraisers can reliably provide a range about their market value that includes the actual sale price of the property. The results are based on a controlled experiment involving seventy-two novices and sixty-nine experts, where each participant was asked to determine a fair market value of a single-family home. Findings indicate that experienced appraisers do in fact exhibit less variation in their valuation of property characteristics, hence there is greater agreement in their market value estimates than is the case with novices. However, more experienced decision-makers tend to be overconfident of their ability: they are less likely to specify a range that includes the sale price than are novices.

Correcting political and consumer misperceptions

While fact-checking has grown dramatically in the last decade, little is known about the relative effectiveness of different formats in correcting false beliefs or overcoming partisan resistance to new information. This article addresses that gap by using theories from communication and psychology to compare two prevailing approaches: An online experiment examined how the use of visual “truth scales” interacts with partisanship to shape the effectiveness of corrections. We find that truth scales make fact-checks more effective in some conditions. Contrary to theoretical predictions and the fears of some journalists, their use does not increase partisan backlash against the correction or the organization that produced it

Occasional Paper No. 092-1: Health Care Perceptions of Nebraska\u27s Urban & Rural Aged

Random samples were drawn in Douglas County, Nebraska (N = 196, mean age = 73.8 years), in the counties surrounding Douglas County also served by the Eastern Nebraska Office on Aging (N = 104, mean age = 72.4 years), and in eleven of the rural Sandhills counties of Nebraska (N = 200, mean age = 76.6). Participants responded to structured interviews of 169 questions that included self-assessed health status, availability of health care and physician services, costs, attitudes toward health care services, health experiences and beliefs. While the Sandhills respondents were significantly older and had less access to health services, they also had fewer annual days of hospitalization. There were no differences in subjective ratings of health or in levels of satisfaction with health care or availability

Studies of the Potential Curve Crossing Problem I. Analysis of Stueckelberg\u27s Method

A detailed critical analysis is made of Stueckelberg\u27s treatment of inelastic transitions at a crossing of two potential curves. Using an asymptotic method analogous to the WKB approximation, Stueckelberg obtained the well-known Landau-Zener-Stueckelberg (LZS) formula for the inelastic transition probability. His method involved the determination of connection formulas linking amplitudes associated with his asymptotic approximants on either side of the crossing-point region. Here we show that (a) Stueckelberg\u27s asymptotic approximants are just the WKB approximants for elastic scattering on the adiabatic (noncrossing) potential curves; (b) Stueckelberg\u27s method for obtaining the connection formulas can be put on a rigorous footing, including sufficient conditions for its validity, using the classical trajectory equations derivable from a general semiclassical theory of inelastic atomic collisions; (c) there is an undetermined phase in the S matrix, which Stueckelberg incorrectly assumed to be zero, and which has the value 14π in the distorted-wave approximation; (d) Stueckelberg\u27s derivation is not valid whenever the inelastic transition probability is small, either in the rapid-passage (diabatic) case or the near-adiabatic limit; (e) for realistic model parameters, the conditions needed for Stueckelberg\u27s derivation to be valid are almost never satisfied. Since the LZS formula is known from numerical computations to be valid under some conditions when the Stueckelberg derivation is not valid, we conclude that analysis via connection-formula methods is not a useful technique for treating the crossing problem. In an appendix we derive an analytical result for the Stokes\u27s constants determining the Stueckelberg connection formulas. The result is an absolutely convergent, infinite series whose numerical evaluation would yield exactly the unknown phase associated with the LZS formula

\u3ci\u3eParavitellotrema overstreeti\u3c/i\u3e Sp. n. (Digenea: Hemiuridae) from the Colombian Freshwater Stingray \u3ci\u3ePotamotrygon magdalenae\u3c/i\u3e Dumeri

Paravitellotrema overstreeti from the freshwater stingray Potamotrygon magdalenae in northern Colombia most closely resembles P. thorsoni by possessing a muscular sinus organ and sinus sac as well as exhibiting a saccate rather than elongate prostatic vesicle, It differs by possessing lobate rather than spherical vitellaria, a smaller sinus organ and sinus sac, elongate rather than diamond-shaped prostatic cells enclosed in a delicate membrane rather than free in the parenchyma, and a metraterm joining the hermaphroditic duct immediately anterior to the prostatic vesicle rather than at the base of the sinus organ

Two New Species of \u3ci\u3eAcanthobothrium\u3c/i\u3e Van Beneden 1849 (Cestoidea: Tetraphyllidea) from Freshwater Stingrays in South America

Two new species of Acanthobothrium are reported from freshwater stingrays in northern South America. Acanthobothrium quinonesi sp. n. is described from Potamotrygon magdalenae Dumeril collected from the Magdalena River in northern Colombia and A. amazonensis sp. n. from P. circularis Garman collected in the Itacuai River of northwestern Brazil. Acanthobothrium quinonesi differs from A. amazonensis by having a smaller and anteriorly-curved cirrus sac, 43-60 rather than 50-72 testes, and bothridial hooks 100-142 μm long rather than 145-184 μm long. Characters used in the taxonomy of Acanthobothrium species are listed to show that the new species resemble each other and A. terezae, also from a South American freshwater stingray, more than they do any other members of the genus

Two New Tetraphyllidean Cestodes from \u3ci\u3ePotamotrygon circularis\u3c/i\u3e Garman (Chondrichthyes: Potamotrygonidae) in the Itacnai River, Brazill

The new genus Rhinebothroides is proposed to include three species of Rhinebothriumlike cestodes parasitizing freshwater stingrays in South America. They differ from Rhinebothrium species by having squared rather than elongate bothridia, by possessing internal seminal vesicles, and by exhibiting terminal genitalia at the ovarian level. Rhinebothroides circularisi sp. n. in Potamotrygon circularis from the Itacuai River in northwestern Brazil differs from R. moralarai by having more testes and bothridial loculi and differs from R. scorzai by lacking vitelline follicles proximate to the genital pore, by having a straight rather than coiled vagina, and by possessing craspedote rather than acraspedote proglottids. Potamotrygon circularis from the Itacuai River also hosted Potamotrygonocestus amazonensis sp. n. which differs from the only other member of the genus, P. magdalenensis, by having bothridial hooks 58-78µm long rather than 43-55 µm long, by possessing a shallow genital atrium rather than lacking one, and by having follicular rather than compact vitellaria