Agricultural policy and strategic investment in information technology

In this article the perspective shifts to the “upstream” end of the agricultural knowledge and information system (AKIS). Because knowledge policy and strategic decision-making are not the prerogative of the public sector, organizations such as cooperative unions and multinational companies are included. After considering the influence of the changing environment on the nature of the AKIS, the role of knowledge management and policy in the emerging knowledge and information market is examined. Special attention is given to public and private R&D. The article then looks where information technology (IT) fits in and what considerations determine strategic investment in IT projects and sustained services. Some of the European experiences with this strategic investment are evaluated.     

VSearch: Macintosh software for experiments in visual search

In this paper, we describe software that turns a Macintosh computer into an off-the-shelf tool for experiments on visual search. Our design goals included portability (between members of the Macintosh computer family and between various research settings), user-friendliness (equivalent to Macintosh programming standards), flexibility (to allow replication and extension of important experiments on visual search), and adaptability (very short design-to-data and data-to-analysis turnaround times). We describe how the software meets these goals in three major phases of an experiment: stimulus construction, experimental control, and statistical analysis. We then list several landmark studies of visual search that can be easily designed and extended with the software. Finally, we outline plans for expanding the experimental variations that will be supported in future versions of the software.     

PIGEONS ARE SENSITIVE TO THE SPATIAL ORGANIZATION OF COMPLEX VISUAL STIMULI

Abstract— Two experiments investigated the role of spatial organisation in the discrimination and generalization of complex visual stimuli by pigeons. In Experiment 1, after pigeons had been trained to discriminate line drawings of four objects, they were tested with novel pictures in which the same component parts of the objects were spatially rearranged. The spatially scrambled pictures led to a dramatic drop in recognition accuracy, hut responding remained above chance. In Experiment 2, pigeons reached a high level of discriminative performance when required to choose among four different spatial arrangements of the same object parts. These results confirm Cerella's (1980) conclusion that pigeons discriminate the component parts of complex visual stimuli, but. unless it is assumed that the scrambling deleted or created emergent features, the results disconfirm his conclusion that spatial organization plays no role in pigeons' picture perception.     

ELI: An Interactive Elicitation Technique for Subjective Probability Distributions

Uncertain knowledge about continuous quantities is usually formalized through subjective probability distributions (SPD′s). However, results from past experimental research have often pointed to the rather poor quality of SPD′s. Moreover, previous attempts to improve SPD quality frequently appeared to be only partly successful; overconfidence especially proved to be an exceptionally persistent phenomenon. In the present study, method-induced biases in particular are considered to be responsible for the poor quality of SPD′s, and an alternative means for eliciting uncertain knowledge was designed to meet fundamental quality criteria to a more satisfactory degree. The direct realization of a proper scoring rule in a graphically oriented interactive computer program is one of the central features of this new elicitation technique, ELI. An experiment with 48 subjects was carried out to evaluate ELI performance and to compare it with the performance of (a) an existing elicitation technique and (b) a simple technique that only asks for a best guess and a lower and upper bound. The three techniques were evaluated and compared with respect to their contribution to reliable and valid SPD′s and with respect to their practical usefulness. The results indicated that for ELI the fundamental requirements were realized to a great extent. Furthermore, compared with the two other techniques, ELI performance appeared to be superior. In particular, only with the support of ELI did overconfidence appear to be almost absent.     

Order effects in belief updating with consistent and inconsistent evidence

The current study tests for the presence of differential order effects in evaluation tasks with consistent and inconsistent evidence as predicted by the Hogarth and Einhorn (1992) belief-adjustment model. The results, based on both between-subjects and within-subjects experiments, demonstrate that there were significant recency effects with inconsistent evidence as predicted, larger recency effects when the inconsistent evidence was farther apart in subjective value as predicted, and significant recency effects even when subjects were given training designed to both help them understand the task as completely as possible and to be better able to assess the pieces of evidence. By including a within-subjects design, we were able to demonstrate that the difference in subjective value between two pieces of evidence is the primary factor influencing the magnitude of the recency effect, regardless of whether the evidence is consistent or inconsistent. This latter finding is unique and contrary to previous research and theory.     

The effects of exposure to different sources of sexual information on sexual behavior: Comparing a “sex-expert system” to other educational material

Sexpert, an expert computer program designed to counsel couples on their sexual relationships, was evaluated. Eighty-one heterosexual couples were assigned to one of three experimental manipulations (Sexpert, video, and self-help book) or a control condition. Daily sexual behavior monitoring forms and structured retrospective reports served as measures of baseline and post-manipulation behavior. Daily monitoring of sexual behavior failed to show significant changes occurring after the manipulations. However, retrospective data concerning the postmanipulation period show that compared with the control, the Sexpert, video, and book manipulations had a significant positive impact on couples’ sexual behavior, communication, and learning about sexuality. Sexpert, video, and book were similarly evaluated, except that Sexpert was evaluated as more engaging. In addition, subjects retrospectively reported positive changes in communication, relationship satisfaction, and sexual behavior during the baseline period. This suggests that daily behavioral monitoring is intrusive and may confound the variables measured by it.     

Relation of parental support and control to adolescents' externalizing symptomatology and substance use: A longitudinal examination of curvilinear effects

Past research has generated inconsistent findings regarding the relation of parental control and support to adolescent problem behaviors. Using two waves of data collected 1 year apart, the current study examined the influence of parental control and support on adolescents' externalizing symptoms, alcohol use, and illicit substance use. A sample of adolescents and their parents (@#@ N =454) was studied, within which approximately half of the adolescents were at high risk because of parental alcoholism. Multipleregression analyses of crosssectional data showed a negative quadratic relation between parental control and adolescent externalizing symptomatology, and between parental control and adolescent illicit substance use. Parental control had a negative linear relation to adolescent alcohol use. Parental support showed a negative quadratic relation to adolescent illicit substance use, and negative linear relations to adolescent alcohol use and externalizing symptoms. Although longitudinally adjusted contemporaneous results were consistent with crosssectional findings, parental support and control were prospectively related only to adolescent alcohol use. The quadratic relations suggest that adolescents who receive either extreme of parental support or control are at risk for problem behaviors.