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Kinds of Preferences Terms modified by Preferences Selected AbstractsSEX CHROMOSOME LINKAGE OF MATE PREFERENCE AND COLOR SIGNAL MAINTAINS ASSORTATIVE MATING BETWEEN INTERBREEDING FINCH MORPHSEVOLUTION, Issue 5 2010Sarah R. Pryke Assortative mating is a key aspect in the speciation process because it is important for both initial divergence and maintenance of distinct species. However, it remains a challenge to explain how assortative mating evolves when diverging populations are undergoing gene flow (e.g., during hybridization). Here I experimentally test how assortative mating is maintained with frequent gene flow between diverged head-color morphs of the Gouldian finch (Erythrura gouldiae). Contrary to the predominant view on the development of sexual preferences in birds, cross-fostered offspring did not imprint on the phenotype of their conspecific (red or black morphs) or heterospecific (Bengalese finch) foster parents. Instead, the mating preferences of F1 and F2 intermorph-hybrids are consistent with inheritance on the Z chromosomes, which are also the location for genes controlling color expression and the genes causing low fitness of intermorph-hybrids. Genetic associations between color signal and preference loci on the sex chromosomes may prevent recombination from breaking down these associations when the morphs interbreed, helping to maintain assortative mating in the face of gene flow. Although sex linkage of reproductively isolating traits is theoretically expected to promote speciation, social and ecological constraints may enforce frequent interbreeding between the morphs, thus preventing complete reproductive isolation. [source] A NOVEL PREFERENCE FOR AN INVASIVE PLANT AS A MECHANISM FOR ANIMAL HYBRID SPECIATIONEVOLUTION, Issue 2 2007Dietmar Schwarz Homoploid hybrid speciation,speciation via hybridization without a change in chromosome number,is rarely documented and poorly understood in animals. In particular, the mechanisms by which animal homoploid hybrid species become ecologically and reproductively isolated from their parents are hypothetical and remain largely untested by experiments. For the many host-specific parasites that mate on their host, choosing the right host is the most important ecological and reproductive barrier between these species. One example of a host-specific parasite is the Lonicera fly, a population of tephritid fruit flies that evolved within the last 250 years likely by hybridization between two native Rhagoletis species following a host shift to invasive honeysuckle. We studied the host preference of the Lonicera fly and its putative parent species in laboratory experiments. The Lonicera fly prefers its new host, introduced honeysuckle, over the hosts of both parental species, demonstrating the rapid acquisition of preference for a new host as a means of behavioral isolation from the parent species. The parent taxa discriminate against each other's native hosts, but both accept honeysuckle fruit, leaving the potential for asymmetric gene flow from the parent species. Importantly, this pattern allows us to formulate hypotheses about the initial formation of the Lonicera fly. As mating partners from the two parent taxa are more likely to meet on invasive honeysuckle than on their respective native hosts, independent acceptance of honeysuckle by both parents likely preceded hybridization. We propose that invasive honeysuckle served as a catalyst for the local breakdown of reproductive isolation between the native parent species, a novel consequence of the introduction of an exotic weed. We describe behavioral mechanisms that explain the initial hybridization and subsequent reproductive isolation of the hybrid Lonicera fly. These results provide experimental support for a combination of host shift and hybridization as a model for hybrid speciation in parasitic animals. [source] RELATIVE ABUNDANCE AND THE SPECIES-SPECIFIC REINFORCEMENT OF MALE MATING PREFERENCE IN THE CHRYSOCHUS (COLEOPTERA: CHRYSOMELIDAE) HYBRID ZONEEVOLUTION, Issue 12 2005Merrill A. Peterson Abstract Most studies of reinforcement have focused on the evolution of either female choice or male mating cues, following the long-held view in sexual selection theory that mating mastakes are typically more costly for females than for males. However, factors such as conspecific sperm precedence can buffer females against the cost of mating mistakes, suggesting that in some hybrid zones mating mistakes may be more costly for males than for females. Thus, the historical bias in reinforcement research may underestimate its frequency. In this study, we present evidence that reinforcement has driven the evolution of male choice in a hybrid zone between teh highly promiscuous lealf beetles chyrsochus cobaltinus and C. auratus, the hybrids of which have extremely low fitness. In addition, there is evidence for male choice in these beetles and that male mating mistakes may be costly, due to reduced opportunities to mate with conspecific females. The present study combines laboratory and field methods to quantify the strenght of sexual isolation, test the hypothesis of reproductive character displacement, and assess the link between relative abundance and the strenght of selection against hybridization. We document that, while sexual isolation is weak, it is sufficient to produce positive assortative mating. In addtion, reproductive character displacement was only detected in the relatively rare species. The strong postzygotic barriers in this system are sufficient to generate the bimodality that characterizes this hybrid zone, but the weak sexual isolation is not, calling into question whether strong prezygotic isolation is necessary for the maintenance of bimodality. Growing evidence that the cost of mating mistakes is sufficient to shape the evolution of male mate choice suggests that the reinforecement of male mate choice may prove to be a widespread occurrence. [source] FEMALE SOLDIER BEETLES DISPLAY A FLEXIBLE PREFERENCE FOR SELECTIVELY FAVORED MALE PHENOTYPESEVOLUTION, Issue 5 2005Denson Kelly Mclain Abstract In Georgia (USA) the soldier beetle, Chauliognathus pennsylvanicus (Coleoptera; Cantharidae), exhibits clinal variation in the length of the spot on its elytron. This suggests that the viability of phenotypes varies by habitat. Evidence of viability selection comes from within-site changes in the spot length distribution across a breeding season. When males with spots of intermediate length became less frequent, they became disproportionately less likely to mate, consistent with either a loss of vigor among remaining males or female rejection of disfavored phenotypes. Persistent, daily courtship by males provides females with the opportunity to track changes in male phenotype frequency and to exercise choice for phenotypes favored under natural selection. A laboratory experiment in which the frequency of one spot morph (long) or the other (short) was increased from 25% to 75% over a period of 30 days revealed that females possess a flexible preference that leads them to prefer whichever spot type has become more common over time. A haploid genetic model demonstrates that a flexible female preference for the locally favored male phenotype can be selected for when different viability alleles, genetically correlated with the male trait, are favored in different habitats that are linked by gene flow. Thus, migration between different kinds of habitat patches of a metapopulation could maintain the variation in male quality. This variation favors female choice for any trait that is directly or indirectly favored by natural selection. Such choice imparts positive frequency-dependent selection that could rapidly fix traits pleiotropically linked to viability. Rapid fixation would cause differentiation between populations of colonizing species as females exercise choice for mates favored under new ecological conditions. [source] SEX DIFFERENCES IN THE PREFERENCE FOR PLACE OF DEATH IN COMMUNITY-DWELLING ELDERLY PEOPLE IN JAPANJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2008Miyako Yamasaki MD No abstract is available for this article. [source] EFFECT OF CaCl2 AND CONVECTIVE-OSMOTIC DRYING ON TEXTURE AND PREFERENCE OF APPLEJOURNAL OF FOOD QUALITY, Issue 6 2006L.A. OCHOA-MARTÍNEZ ABSTRACT Conventional air-drying combined with osmotic dehydration was researched as a potential method for drying apple cubes of superior quality. Samples were pretreated with CaCl2 at different temperatures and times. Pretreated apple cubes were dehydrated in a tray dryer. Then, osmotic dehydration with sucrose solutions was carried out. The curves for osmotic dehydration showed that the gain of solids was higher when 40% of water was removed by convective drying while the loss of weight was lower at the same level of dehydration at 65°Brix. Texture measurements indicated that the temperature of pretreatment affected the hardness and cohesiveness. Hardness values were higher at 40C, while cohesiveness values were lower at the same temperature. The CaCl2 at a given temperature did not have a significant effect on texture. Sensory evaluation showed that samples pretreated at 25C and osmotically dried at 50°Brix had the higher preference by the judges. [source] ASSESSMENT OF PREFERENCE WITH CONTROLS FOR RESPONSE BIAS OPERATING IN THE TEST SITUATION: A PRACTICAL EXAMPLE USING OMEGA-3 ENRICHED WHOLEGRAIN BREADS WITH ECUADORIAN CONSUMERSJOURNAL OF SENSORY STUDIES, Issue 5 2010YAMILLA ALVAREZ-COUREAUX ABSTRACT Ecuadorian consumers performed paired preference tests between sunflower rye bread and artisan wholegrain bread enriched with omega-3 fatty acids. Preferences for each were split fairly evenly. Further difference tests suggested that these preferences were elicited by visual rather than flavor/texture cues. The preference test included a "placebo" pair of "identical" stimuli to assess statistically whether the responses to the two test stimuli were merely because of response biases operating in the test situation and not differences in their sensory attributes. The concept of an "operational preference" was introduced to understand some of the ambiguities involved in the definition of preference. PRACTICAL APPLICATIONS The measurement of preference and acceptance of foods is important for product development and decisions regarding the launching of new products on to the market. The paired preference test has several problems associated with its design and analysis, and these are worthy of investigation. This article uses a practical example to illustrate some procedures developed as solutions to these challenges. Solutions to the problems involved in preference testing are essential so that the food industry can obtain trustworthy data. [source] PREFERENCE FOR ONE OF TWO IDENTICAL STIMULI: EXPECTATIONS, EXPLICIT INSTRUCTIONS AND PERSONAL TRAITSJOURNAL OF SENSORY STUDIES, Issue 2010KATHRYN W. CHAPMAN ABSTRACT Most consumers, given two identical food samples, express a preference for one, rather than choosing a no-preference option. The stability and potential causes of this seemingly irrational preference were examined across three trials under different conditions, specifically, when the first test pair was identical or different, and when participants were explicitly told that the pairs would often be identical. Choice of no preference typically increased from the first to second trial, especially for groups who saw a pair of different samples on the first trial. The explicit instruction that samples might be the same failed to reduce expressing a preference on the initial trial although it had some effect on later trials. Analysis, by individuals, of sequences of preference or no-preference responses across trials support independence of sequential responses and argue against stable personal traits as a predictor of preference choice. PRACTICAL APPLICATIONS More research needs to be done to understand the origins and operation of biases in preference tests. When tested under conditions in which the samples differ only slightly, participants tend to avoid the no-preference option. This is potentially important when interpreting the results of preference tests and assigning practical significance to their outcomes. Also, single trial testing may produce somewhat different results from multi-trial testing, the latter allowing for examination of effects of variation in recent experience. [source] DUNG BY PREFERENCE: THE CHOICE OF FUEL AS AN EXAMPLE OF HOW ANDEAN POTTERY PRODUCTION IS EMBEDDED WITHIN WIDER TECHNICAL, SOCIAL, AND ECONOMIC PRACTICES,ARCHAEOMETRY, Issue 1 2000B. SILLAR A discussion of how Andean potters acquire and use their fuels is used to demonstrate the ,embedded'nature of ceramic technology. The most common choice of fuel in the highlands of Peru and Bolivia is animal dung (mainly cow, sheep, and llama). This technological choice is related to wider social and economic practices (particularly in relation to animal husbandry) which has further repercussions that affect other technologies (such as agriculture practices). Such a succession of interrelated activities is not unique to pottery; it is fundamental to all technologies and should be considered within archaeological analysis. [source] PUBLIC PREFERENCES FOR REHABILITATION VERSUS INCARCERATION OF JUVENILE OFFENDERS: EVIDENCE FROM A CONTINGENT VALUATION SURVEY,CRIMINOLOGY AND PUBLIC POLICY, Issue 4 2006DANIEL S. NAGIN Research Summary: Accurately gauging the public's support for alternative responses to juvenile offending is important, because policy makers often justify expenditures for punitive juvenile justice reforms on the basis of popular demand for tougher policies. In this study, we assess public support for both punitively and nonpunitively oriented juvenile justice policies by measuring respondents' willingness to pay for various policy proposals. We employ a methodology known as "contingent valuation" (CV) that permits the comparison of respondents' willingness to pay (WTP) for competing policy alternatives. Specifically, we compare CV-based estimates for the public's WTP for two distinctively different responses to serious juvenile crime: incarceration and rehabilitation. An additional focus of our analysis is an examination of the public's WTP for an early childhood prevention program. The analysis indicates that the public is at least as willing to pay for rehabilitation as punishment for juvenile offenders and that WTP for early childhood prevention is also substantial. Implications and future research directions are outlined. Policy Implications: The findings suggest that lawmakers should more actively consider policies grounded in rehabilitation, and, perhaps, be slower to advocate for punitive reforms in response to public concern over high-profile juvenile crimes. Additionally, our willingness to pay findings offer encouragement to lawmakers who are uncomfortable with the recent trend toward punitive juvenile justice policies and would like to initiate more moderate reforms. Such lawmakers may be reassured that the public response to such initiatives will not be hostile. Just as importantly, reforms that emphasize leniency and rehabilitation can be justified economically as welfare-enhancing expenditures of public funds. The evidence that the public values rehabilitation more than increased incarceration should be important information to cost-conscious legislators considering how to allocate public funds. Cost-conscious legislatures may become disenchanted with punitive juvenile justice policies on economic grounds and pursue policies that place greater emphasis on rehabilitation. They may be reassured, on the basis of our findings, that the public will support this move. [source] A NEW ROLE FOR CONSUMERS' PREFERENCES IN THE PROVISION OF HEALTHCAREECONOMIC AFFAIRS, Issue 3 2006Harry Telser In the present allocation of resources in healthcare, preferences of consumers as the ultimate financiers of healthcare services are judged to be of little relevance. This state of affairs is being challenged because the past decade has seen great progress in the measurement of preferences, or more precisely, willingness-to-pay (WTP) as applied to healthcare services. This article reports evidence on WTP of the Swiss population with regard to three hypothetical modifications of the drug benefit to be covered by social health insurance: delaying access to the most recent therapeutic innovations (among them, drugs) by two years in exchange for a reduction of the monthly premium; substituting original preparations by generics, again in return for a lowered premium; and the exclusion of preparations for the treatment of minor complaints from the drug benefit. Using discrete-choice experiments, WTP and its determinants are estimated. Average WTP for avoiding such a delay (which acts across the board) is much higher than for eschewing the exclusive use of generics (which are claimed to be largely equivalent to the original) or the retention of ,unimportant' drugs in the list of benefits , a rating predicted by economic theory. In addition, a great deal of preference heterogeneity between the French-speaking minority and the German-speaking majority was found, pointing to considerable efficiency losses caused by uniformity of social health insurance. [source] ON THE PREFERENCES OF PRINCIPALS AND AGENTSECONOMIC INQUIRY, Issue 2 2010MARCO CASTILLO One of the reasons why market economies are able to thrive is that they exploit the willingness of entrepreneurs to take risks that laborers might prefer to avoid. Markets work because they remunerate good judgment and punish mistakes. Indeed, modern contract theory is based on the assumption that principals are less risk averse than agents. We investigate if the risk preferences of entrepreneurs are different from those of laborers by implementing experiments with a random sample of the population in a fast-growing, small-manufacturing, economic cluster. As assumed by theory, we find that entrepreneurs are more likely to take risks than hired managers. These results are robust to the inclusion of a series of controls. This lends support to the idea that risk preferences is an important determinant of selection into occupations. Finally, our lotteries are good predictors of financial decisions, thus giving support to the external validity of our risk measures and experimental methods (JEL C93, D81, D86). [source] MATE CHOICE AND HUMAN STATURE: HOMOGAMY AS A UNIFIED FRAMEWORK FOR UNDERSTANDING MATING PREFERENCESEVOLUTION, Issue 8 2010Alexandre Courtiol Assortative mating for human height has long attracted interest in evolutionary biology, and the phenomenon has been demonstrated in numerous human populations. It is often argued that mating preferences generate this pattern, but other processes can also induce trait correlations between mates. Here, we present a methodology tailored to quantify continuous preferences based on choice experiments between pairs of stimuli. In particular, it is possible to explore determinants of interindividual variations in preferences, such as the height of the chooser. We collected data from a sample of 200 individuals from France. Measurements obtained show that the perception of attractiveness depends on both the height of the stimuli and the stature of the individual who judged them. Therefore, this study demonstrates that homogamy is present at the level of preferences for both sexes. We also show that measurements of the function describing this homogamy are concordant with several distinct mating rules proposed in the literature. In addition, the quantitative approach introduced here fulfills metrics that can be used to compare groups of individuals. In particular, our results reveal an important disagreement between sexes regarding height preferences in the context of mutual mate choice. Finally, both women and men prefer individuals who are significantly taller than average. All major findings are confirmed by a reanalysis of previously published data. [source] HERITABILITY OF AND EARLY ENVIRONMENT EFFECTS ON VARIATION IN MATING PREFERENCESEVOLUTION, Issue 4 2010Holger Schielzeth Many species show substantial between-individual variation in mating preferences, but studying the causes of such variation remains a challenge. For example, the relative importance of heritable variation versus shared early environment effects (like sexual imprinting) on mating preferences has never been quantified in a population of animals. Here, we estimate the heritability of and early rearing effects on mate choice decisions in zebra finches based on the similarity of choices between pairs of genetic sisters raised apart and pairs of unrelated foster sisters. We found a low and nonsignificant heritability of preferences and no significant shared early rearing effects. A literature review shows that a low heritability of preferences is rather typical, whereas empirical tests for the relevance of sexual imprinting within populations are currently limited to very few studies. Although effects on preference functions (i.e., which male to prefer) were weak, we found strong individual consistency in choice behavior and part of this variation was heritable. It seems likely that variation in choice behavior (choosiness, responsiveness, sampling behavior) would produce patterns of nonrandom mating and this might be the more important source of between-individual differences in mating patterns. [source] THE EVOLUTION OF FEMALE MATING PREFERENCES: DIFFERENTIATION FROM SPECIES WITH PROMISCUOUS MALES CAN PROMOTE SPECIATIONEVOLUTION, Issue 10 2006Mark A. McPeek Abstract Females of many species are frequently courted by promiscuous males of their own and other closely related species. Such mating interactions may impose strong selection on female mating preferences to favor trait values in conspecific males that allow females to discriminate them from their heterospecific rivals. We explore the consequences of such selection in models of the evolution of female mating preferences when females must interact with heterospecific males from which they are completely postreproductively isolated. Specifically, we allow the values of both the most preferred male trait and the tolerance of females for males that deviate from this most preferred trait to evolve. Also, we consider situations in which females base their mating decisions on multiple male traits and must interact with males of multiple species. Females will rapidly differentiate in preference when they sometimes mistake heterospecific males for suitable mates, and the differentiation of female preference will select for conspecific male traits to differentiate as well. In most circumstances, this differentiation continues indefinitely, but slows substantially once females are differentiated enough to make mistakes rare. Populations of females with broader preference functions (i.e., broader tolerance for males with trait values that deviate from females most preferred values) will evolve further to differentiate if the shape of the function cannot evolve. Also, the magnitude of separation that evolves is larger and achieved faster when conspecific males have lower relative abundance. The direction of differentiation is also very sensitive to initial conditions if females base their mate choices on multiple male traits. We discuss how these selection pressures on female mate choice may lead to speciation by generating differentiation among populations of a progenitor species that experiences different assemblages of heterospecifics. Opportunities for differentiation increase as the number of traits involved in mate choice increase and as the number of species involved increases. We suggest that this mode of speciation may have been particularly prevalent in response to the cycles of climatic change throughout the Quaternary that forced the assembly and disassembly of entire communities on a continentwide basis. [source] ADVERTISEMENT-CALL PREFERENCES IN DIPLOID-TETRAPLOID TREEFROGS (HYLA CHRYSOSCELIS AND HYLA VERSICOLOR): IMPLICATIONS FOR MATE CHOICE AND THE EVOLUTION OF COMMUNICATION SYSTEMSEVOLUTION, Issue 2 2005H. Carl Gerhardt Abstract Signals used for mate choice and receiver preferences are often assumed to coevolve in a lock-step fashion. However, sender-receiver coevolution can also be nonparallel: even if species differences in signals are mainly quantitative, females of some closely related species have qualitatively different preferences and underlying mechanisms. T o-alternative playback experiments using synthetic calls that differed in fine-scale temporal properties identified the receiver criteria in females of the treefrog Hyla chrysoscelis for comparison with female criteria in a cryptic tetraploid species (H. versicolor); detailed preference functions were also generated for both species based on natural patterns of variation in temporal properties. The species were similar in three respects: (1) pulses of constant frequency were as attractive as the frequency-modulated pulses typical of conspecific calls; (2) changes in preferences with temperature paralleled temperature-dependent changes in male calls; and (3) preference functions were unimodal, with weakly defined peaks estimated at values slightly higher than the estimated means in conspecific calls. There were also species differences: (1) preference function slopes were steeper in H. chrysoscelis than in H. versicolor; (2) preferences were more intensity independent in H. chrysoscelis than in H. versicolor; (3) a synergistic effect of differences in pulse rate and shape on preference strength occurred in H. versicolor but not in H. chrysoscelis; and (4) a preference for the pulse shape typical of conspecific calls was expressed at the species-typical pulse duration in H. versicolor but not in H. chrysoscelis. However, females of H. chrysoscelis did express a preference based on pulse shape when tested with longer-than-average pulses, suggesting a hypothesis that could account for some examples of nonparallel coevolution. Namely, preferences can be hidden or revealed depending on the direction of quantitative change in a signal property relative to the threshold for resolving differences in that property. The results of the experiments reported here also predict patterns of mate choice within and between contemporary populations. First, intraspecific mate choice in both species is expected to be strongly influenced by variation in temperature among calling males. Second, simultaneous differences in pulse rate and pulse shape are required for effective species discrimination by females of H. versicolor but not by females of H. chrysoscelis. Third, there is greater potential for sexual selection within populations and for discrimination against calls produced by males in other geographically remote populations in H. chrysoscelis than in H. versicolor. [source] SEXUAL SELECTION AND THE EVOLUTION OF COSTLY FEMALE PREFERENCES: SPATIAL EFFECTSEVOLUTION, Issue 3 2000Troy Day Abstract., Models of Fisher's runaway process show that if there is a cost to female preference, no preference or male trait exaggeration will evolve. Surprisingly, this is true no matter how small the cost, which reveals that these models of Fisher's process are structurally unstable (Bulmer 1989). Here a model of Fisher's runaway process is presented to demonstrate that costly female preference evolves very easily when space is explicitly included in the model. The only requirement is that the optimal male phenotype changes across the species' range. The model shows that the spatial average of the female preference and male trait reach an evolutionary equilibrium that is identical to those of nonspatial models, but that the preference and male trait can deviate greatly from these averages at any point in space. For example, if random mating results in the lowest cost to females, then at equilibrium the spatial average preference will be zero. Nevertheless, there will be some locations at which females prefer males with larger ornaments and others where they prefer males with smaller ornaments. Results also show that the structural instability of nonspatial models of Fisher's process is less of a problem in spatial models. In particular, many of the main qualitative features of cost-free spatial models of Fisher's process remain valid even when there are small costs of female preference. Finally, the model shows that abrupt changes in the optimal male phenotype across space can result in an amplification of this pattern when preference has a small cost, but it can also result in a pattern similar to reproductive character displacement. Which of these occurs depends on the magnitude of the cost of female preference. This suggests that some patterns of reproductive character displacement in nature might be explained simply by sexual selection rather than by hybrid dysgenesis and reinforcement. [source] PHYSICAL AND COGNITIVE FUNCTIONING AND RESUSCITATION PREFERENCES OF AGED PATIENTSJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2005Marja-Liisa Laakkonen MD No abstract is available for this article. [source] CONSUMER PREFERENCES FOR PATHOGEN-REDUCING TECHNOLOGIES IN BEEF,JOURNAL OF FOOD SAFETY, Issue 2 2001KRISTA FINGERHUT ABSTRACT Two surveys were conducted by mail to evaluate consumers' preferences for beef treated by the steam and hot-water pasteurization technologies, in a comparison with beef treated by irradiation and nontechnology treated "regular" beef. More than 64% of the respondents reported that they preferred ground beef treated by irradiation to that treated by the two pathogen-reducing technologies. More than 87% of the respondents stated that they preferred ground beef treated by the two technologies to nontechnology treated beef. Sixty percent of the respondents reported that they were willing to pay for beef treated by the two pathogen-reducing technologies with an averaged willingness-to-pay of 0.36/lb over nontechnology treated beef. Compared with their counterparts; women, those having a better self-reported health status, and those with children at home (, 18 years of age) were more likely to report a preference for beef treated by the two heat-related pasteurization technologies. The income level of the respondents was negatively associated with their preference for beef treated by the two heat-related pasteurization technologies. The strong consumer preference coupled with willingness-to-pay for beef treated by the two pathogen-reducing technologies, suggest that consumers are willing to bear the cost of using these technologies if beef packers would invest in such technologies as a means of improving the quality of their products. [source] CONSUMER PREFERENCES FOR VISUALLY PRESENTED MEALSJOURNAL OF SENSORY STUDIES, Issue 2 2009HANS HENRIK REISFELT ABSTRACT The aim of the study was to investigate consumers' preferences for variations of a visually presented meal. The study was conducted in three middle-sized Danish towns, including 768 respondents who were presented with a computerized questionnaire that initially displayed four consecutive series of photos. The series each consisted of eight unique photos of randomized food dishes arranged around the center square in a 3 × 3 array. Five meal components, each with two levels, were investigated. One level of each component was used for each photo, in total 25 = 32 combinations. The respondents were asked to select the meal they preferred the most, the second most and the least, respectively. Significant interactions were found between meal components and background variables such as, gender, age, geographic variables, purchase store and level of education. The current procedure can be applied to help solve a number of problems involving consumer choices. PRACTICAL APPLICATIONS This study outlines an approach to use visual images for investigations of food. Our results suggest that rather complex food stimuli of great similarity can be used to subdivide consumers based on sociodemographic background variables. We present an efficient and cheap quick method that provides and captures more information than an ordinary survey that focuses merely on the most preferred option. As a prerequisite for success, stimuli should be well known and appropriately selected. Hence, the present quick method can easily be applied for several practical purposes, such as pretesting, labeling, product flop prevention, and for specific optimization and selection tasks, e.g., convenience meals and institutional meal services in various contexts. The conjoint layout used allows for late-based segmentation. It further allows for estimation on aggregate as well as individual level. The current approach is useful for database and/or online implementation. [source] PAIRED PREFERENCE TESTS: "50:50" AND "ALTERNATING" NO PREFERENCESJOURNAL OF SENSORY STUDIES, Issue 6 2008HAYDE ALFARO-RODRÍGUEZ ABSTRACT Because the concept of "No Preference" is ambiguous, two types of "No Preference" are defined: a "50:50" No Preference, defined operationally as consumers presented with both products having a 50% chance of choosing either, and an "Alternating" No Preference, where the probability is not 50%. The consumer would be more likely to choose one of the products. However, later, he or she might choose the other product. To investigate this, paired preference tests were performed with and without the "No Preference" option for various products. No discernible trend was noted for consumers who had chosen the "No Preference" option and distributed their votes among the preference options. These consumers and those who changed their preferences were classified according to the "50:50" No Preference and "Alternating" No Preference dichotomy accordingly. PRACTICAL APPLICATIONS Besides the tendency of consumers to report false preferences, paired preference tests have another problem: the concept of "No Preference" is ambiguous. It could mean that consumers liked both products equally and so would always have a 50% chance of choosing either. It could also mean that the probability is not 50% on any one occasion but varies so that one product is chosen on one occasion and the other product on another occasion. To avoid confusing the consumer so as to obtain more valid data, it is important to specify these two meanings of "No Preference." This study is a first step in that direction and should help consumers understand better the instructions for preference tests. [source] HIDDEN AND FALSE "PREFERENCES" ON THE STRUCTURED 9-POINT HEDONIC SCALEJOURNAL OF SENSORY STUDIES, Issue 6 2008XADENI VILLEGAS-RUIZ ABSTRACT An unspecified number of consumers who used a 9-point hedonic scale were frustrated because they could not express preferences for products with the same ratings. Accordingly, consumers were required to rate samples of yogurt on a 9-point structured hedonic scale. Consumers were able to express preference judgments because the testing was performed one-on-one with the experimenter. Thus, it was possible to determine the proportion of consumers who had given the same hedonic response to yogurts but still had preferences for one or other of the stimuli. Further testing, which included a pair of identical yogurts among the stimuli, allowed the proportion of preference and no preference responses elicited by identical stimuli to be determined in this context. Such data are useful as a control condition in preference testing, to assess the proportion of false preferences induced by the experimental conditions. PRACTICAL APPLICATIONS Consumer liking for various products is typically measured using the 9-point structured hedonic scale. Sometimes, consumers will give the same score to two products yet prefer one to the other. Such preferences are not recorded if the consumer is isolated from the experimenter and has no means of reporting them. However, the situation is easily rectified if the experimenter interacts one-on-one with the consumer. Sometimes, false preferences can be obtained from a hedonic scale. This tendency can be monitored by including identical stimuli in the measurements. The present study investigated the extent of such problems so that methods could be devised to address the problem. [source] A STUDY OF CHINESE-ORIGIN AND EUROPEAN-ORIGIN AUSTRALIAN CONSUMERS' TEXTURE PREFERENCES USING A NOVEL EXTRUDED PRODUCTJOURNAL OF SENSORY STUDIES, Issue 5 2001J.M. MURRAY ABSTRACT Diverse food choices and preferences are commonly observed between consumers cross-culturally, however, many aspects of these behavioral differences are not yet fully understood. In order to investigate cross-cultural texture preferences, six extruded snack samples, manufactured under different processing conditions to represent a range of textural characteristics were characterized by a trained panel using descriptive sensory analysis. In parallel, thirty-eight naive European-Origin and thirty-seven naive Chinese-Origin Australian consumers (t = 75) rated their preference for the snacks. The snacks were not representative of any snacks on the market and thus represented a " novel" product in both cultures. Additionally, consumers answered a simple questionnaire and completed the food neophobia scale. Results of descriptive analysis indicated significant differences (p,0.01) between the samples for 13 out of 15 descriptive attributes but no significant differences in preference were found between European-origin and Chinese-origin consumers. However, overall analysis of mean effects indicated that Chinese-origin consumers rated samples significantly higher than European-origin consumers (p,0.05), suggesting a cultural bias in the use of line scales. Gender did not influence texture preference, however, age significantly influenced preference for three of the samples (p,0.05) and analysis of mean effects also indicated differences in consumers' ratings which were related to age. Food neophobia classification did not influence preference, although many more Chinese-origin consumers (28) were classified as neophobic than were European-origin consumers (11). [source] FEEDING PREFERENCES OF THE MONKEY MIA DOLPHINS: RESULTS FROM A SIMULTANEOUS CHOICE PROTOCOLMARINE MAMMAL SCIENCE, Issue 4 2003Lawrence M. Dill Abstract The semiwild beach-feeding bottlenose dolphins (Tursiops aduncus) of Monkey Mia, Western Australia, provide an unparalleled opportunity to examine prey preference of this species. In a series of binary-choice feeding experiments, we took advantage of the animals' willingness to be fed by hand, to explore their preferences for fish species, size, and state (freshly caught or previously frozen). At the end of each beach visit, each dolphin was provided with a pair of fish but allowed to eat only the first one chosen. The dolphins appeared indifferent among the three species of fish offered to them (yellowtail trumpeter, Amniataba caudovittatus; striped trumpeter, Pelates sexlineatus; and western butterfish, Pentapodus vitta), which were of similar body form and matched for mass. Overall, the dolphins showed a slight preference for the larger of two yellowtail trumpeter offered, suggesting the capability for rational choice when there was a basis for it (most likely energy in this case), although there was considerable individual variation. The dolphins did not distinguish between freshly caught and previously frozen yellowtail. The methodology we describe can be used to generate data of potential value for understanding food and habitat selection of wild dolphins, and for modifying management practices for semiwild dolphins at Monkey Mia and elsewhere. [source] SOME REMARKS ON ARBITRAGE AND PREFERENCES IN SECURITIES MARKET MODELSMATHEMATICAL FINANCE, Issue 3 2004Marco Frittelli We introduce the notion of a market-free-lunch that depends on the preferences of all agents participating in the market. In semimartingale models of securities markets, we characterize no arbitrage (NA) and no-free-lunch-with-vanishing-risk (NFLVR) in terms of the market-free-lunch and show that the difference between NA and NFLVR consists in the selection of the class of monotone, respectively monotone and continuous, utility functions that determines the absence of the market-free-lunch. We also provide a direct proof of the equivalence between the absence of a market-free-lunch, with respect to monotone concave preferences, and the existence of an equivalent (local/sigma) martingale measure. [source] SECTOR-SPECIFIC EXTERNALITIES AND STATUS PREFERENCES IN THE UZAWA-LUCAS MODEL,THE JAPANESE ECONOMIC REVIEW, Issue 3 2008KOICHI KAWAMOTO This paper shows that introducing preferences for social status based on human capital holdings modifies the finding of Gómez (2004) that sector-specific externalities associated with human capital in the goods sector do not violate the optimality of the competitive economy in the Uzawa,Lucas model. The effect of an increase in the degree of sector-specific externalities is qualitatively the same as that of an increase in the strength of the desire for status. Hence, paradoxically, a greater degree of sector-specific externalities makes human capital accumulation more excessive from the social point of view. [source] A BROAD PERFORMANCE BENCHMARK BASED ON CITIZENS' PREFERENCES: THE CASE OF SWEDISH PUBLIC TRANSPORTATIONANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 4 2009Magnus Söderberg ABSTRACT,:,Benchmarks have been recommended for assessing the relative performance of local government services. However, these are often narrowly defined and therefore ignore important welfare dimensions. This paper proposes a framework for benchmarking based on a combination of production and cost characteristics and citizens' subjective perceptions. An evaluation consisting of Data Envelopment Analysis (DEA) and different regression models is applied on all 21 Swedish regional public transport authorities, covering the period 2002,2006 (n = 103). The results indicate that the industry as a whole is about 70% efficient and that efficiency can be improved by increasing the sizes of the urban and the bus vehicle-km shares. The optimal ownership structure is to have one large owner combined with about 25 small owners. [source] RISK ATTITUDES AND THE DEMAND FOR PRIVATE HEALTH INSURANCE: THE IMPORTANCE OF ,CAPTIVE PREFERENCES'ANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 4 2009Joan Costa-Font ABSTRACT,:,Captivity to a mainstream public insurer, is hypothesized to constrain the choice of purchasing private health insurance, by influencing risk attitudes. Namely, risk averse individuals are more likely to stay captive to the National Health System (NHS). To empirically test this hypothesis we use a small scale database from Catalonia to explore the determinants of private health insurance (PHI) purchase under different forms of captivity along with a measure of risk attitudes. Our results confirm that the captivity corrections are significant and can potentially bias the estimates of the demand for PHI. Risk aversion increases the probability of an individual being captive to the NHS. The latter suggests a potential behavioural (or cultural) mechanism to isolate the influence of risk attitudes on the demand for PHI in publicly financed health systems. [source] Preference-Based Constrained Optimization with CP-NetsCOMPUTATIONAL INTELLIGENCE, Issue 2 2004Craig Boutilier Many artificial intelligence (AI) tasks, such as product configuration, decision support, and the construction of autonomous agents, involve a process of constrained optimization, that is, optimization of behavior or choices subject to given constraints. In this paper we present an approach for constrained optimization based on a set of hard constraints and a preference ordering represented using a CP-network,a graphical model for representing qualitative preference information. This approach offers both pragmatic and computational advantages. First, it provides a convenient and intuitive tool for specifying the problem, and in particular, the decision maker's preferences. Second, it admits an algorithm for finding the most preferred feasible (Pareto-optimal) outcomes that has the following anytime property: the set of preferred feasible outcomes are enumerated without backtracking. In particular, the first feasible solution generated by this algorithm is Pareto optimal. [source] Designing mouse behavioral tasks relevant to autistic-like behaviors,DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2004Jacqueline N. Crawley Abstract The importance of genetic factors in autism has prompted the development of mutant mouse models to advance our understanding of biological mechanisms underlying autistic behaviors. Mouse models of human neuropsychiatric diseases are designed to optimize (1) face validity, i.e., resemblance to the human symptoms; (2) construct validity, i.e., similarity to the underlying causes of the disease; and (3) predictive validity, i.e., expected responses to treatments that are effective in the human disease. There is a growing need for mouse behavioral tasks with all three types of validity for modeling the symptoms of autism. We are in the process of designing a set of tasks with face validity for the defining features of autism: deficits in appropriate reciprocal social interactions, deficits in verbal social communication, and high levels of ritualistic repetitive behaviors. Social approach is tested in an automated three-chambered apparatus that offers the subject a choice between a familiar environment, a novel environment, and a novel environment containing a stranger mouse. Preference for social novelty is tested in the same apparatus, with a choice between the start chamber, the chamber containing a familiar mouse, and the chamber containing a stranger mouse. Social communication is evaluated by measuring the ultrasonic distress vocalizations emitted by infant mouse pups and the parental response of retrieving the pup to the nest. Resistance to change in ritualistic repetitive behaviors is modeled by forcing a change in habit, including reversal of the spatial location of a reinforcer in a T-maze task and in the Morris water maze. Mouse behavioral tasks that may model additional features of autism are discussed, including tasks relevant to anxiety, seizures, sleep disturbances, and sensory hypersensitivity. Applications of these tests include (1) behavioral phenotyping of transgenic and knockout mice with mutations in genes relevant to autism, (2) characterization of mutant mice derived from random chemical mutagenesis, (3) DNA microarray analyses of genes in inbred strains of mice that differ in social interaction, social communication and resistance to change in habit, and (4) evaluation of proposed therapeutics for the treatment of autism. Published 2004 Wiley-Liss, Inc. MRDD Research Reviews 2004;10:248,258. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||