Showing papers by "University of Oregon published in 1979"
TL;DR: The Organizational Commitment Questionnaire (OCQ) as discussed by the authors ) is a measure of employee commitment to work organizations, developed by Porter and his colleagues, which is based on a series of studies among 2563 employees in nine divergent organizations.
8,144 citations
TL;DR: In this article, Dawes presented evidence that even such improper linear models are superior to clinical intuition when predicting a numerical criterion from numerical predictors, and showed that unit (i.e., equal) weighting is quite robust for making such predictions.
Abstract: Proper linear models are those in which predictor variables are given weights in such a way that the resulting linear composite optimally predicts some criterion of interest; examples of proper linear models are standard regression analysis, discriminant function analysis, and ridge regression analysis. Research summarized in Paul Meehl's book on clinical versus statistical prediction—and a plethora of research stimulated in part by that book—all indicates that when a numerical criterion variable (e.g., graduate grade point average) is to be predicted from numerical predictor variables, proper linear models outperform clinical intuition. Improper linear models are those in which the weights of the predictor variables are obtained by some nonoptimal method; for example, they may be obtained on the basis of intuition, derived from simulating a clinical judge's predictions, or set to be equal. This article presents evidence that even such improper linear models are superior to clinical intuition when predicting a numerical criterion from numerical predictors. In fact, unit (i.e., equal) weighting is quite robust for making such predictions. The article discusses, in some detail, the application of unit weights to decide what bullet the Denver Police Department should use. Finally, the article considers commonly raised technical, psychological, and ethical resistances to using linear models to make important social decisions and presents arguments that could weaken these resistances. Paul MeehPs (1954) book Clinical Versus Statistical Prediction: A Theoretical Analysis and a Review of the Evidence appeared 25 years ago. It reviewed studies indicating that the prediction of numerical criterion variables of psychological interest (e.g., faculty ratings of graduate students who had just obtained a PhD) from numerical predictor variables (e.g., scores on the Graduate Record Examination, grade point averages, ratings of letters of recommendation) is better done by a proper linear model than by the clinical intuition of people presumably skilled in such prediction. The point of this article is to review evidence that even improper linear models may be superior to clinical predictions. Vol. 34, No. 7,571-582 A proper linear model is one in which the weights given to the predictor variables are chosen in such a way as to optimize the relationship between the prediction and the criterion. Simple regression analysis is the most common example of a proper linear model; the predictor variables are weighted in such a way as to maximize the correlation between the subsequent weighted composite and the actual criterion. Discriminant function analysis is another example of a proper linear model; weights are given to the predictor variables in such a way that the resulting linear composites maximize the discrepancy between two or more groups. Ridge regression analysis, another example (Darlington, 1978; Marquardt & Snee, 1975), attempts to assign weights in such a way that the linear composites correlate maximally with the criterion of interest in a new set of data. Thus, there are many types of proper linear models and they have been used in a variety of contexts. One example (Dawes, 1971) was presented in this Journal; it involved the prediction of faculty ratings of graduate students. All graduWork on this article was started at the University of Oregon and Decision Research, Inc., Eugene, Oregon; it was completed while I was a James McKeen Cattell Sabbatical Fellow at the Psychology Department at the University of Michigan and at the Research Center for Group Dynamics at the Institute for Social Research there, I thank all these institutions for their assistance, and I especially thank my friends at them who helped. This article is based in part on invited talks given at the American Psychological Association (August 1977), the University of Washington (February 1978), the Aachen Technological Institute (June 1978), the University of Groeningen (June 1978), the University of Amsterdam (June 1978), the Institute for Social Research at the University of Michigan (September 1978), Miami University, Oxford, Ohio (November 1978), and the University of Chicago School of Business (January 1979). I received valuable feedback from most of the audiences. Requests for reprints should be sent to Robyn M. Dawes, Department of Psychology, University of Oregon, Eugene, Oregon 97403. AMERICAN PSYCHOLOGIST • JULY 1979 • 571 Copyright 1979 by the American Psychological Association, Inc. 0003-066X/79/3407-0571$00.75 ate students at the University of Oregon's Psychology Department who had been admitted between the fall of 1964 and the fall of 1967—and who had not dropped out of the program for nonacademic reasons (e.g., psychosis or marriage)— were rated by the faculty in the spring of 1969; faculty members rated only students whom they felt comfortable rating. The following rating scale was used: S, outstanding; 4, above average; 3, average; 2, below average; 1, dropped out of the program in academic difficulty. Such overall ratings constitute a psychologically interesting criterion because the subjective impressions of faculty members are the main determinants of the job (if any) a student obtains after leaving graduate school. A total of 111 students were in the sample; the number of faculty members rating each of these students ranged from 1 to 20, with the mean number being 5.67 and the median being 5. The ratings were reliable. (To determine the reliability, the ratings were subjected to a oneway analysis of variance in which each student being rated was regarded as a treatment. The resulting between-treatments variance ratio (»j) was .67, and it was significant beyond the .001 level.) These faculty ratings were predicted from a proper linear model based on the student's Graduate Record Examination (GRE) score, the student's undergraduate grade point average (GPA), and a measure of the selectivity of the student's undergraduate institution. The cross-validated multiple correlation between the faculty ratings and predictor variables was .38. Congruent with Meehl's results, the correlation of these latter faculty ratings with the average rating of the people on the admissions committee who selected the students was .19; 2 that is, it accounted for one fourth as much variance. This example is typical of those found in psychological research in this area in that (a) the correlation with the model's predictions is higher than the correlation with clinical prediction, but (b) both correlations are low. These characteristics often lead psychologists to interpret the findings as meaning that while the low correlation of the model indicates that linear modeling is deficient as a method, the even lower correlation of the judges indicates only that the wrong judges were used. An improper linear model is one in which the weights are chosen by some nonoptimal method. They may be chosen to be equal, they may be chosen on the basis of the intuition of the person making the prediction, or they may be chosen at random. Nevertheless, improper models may have great utility. When, for example, the standardized GREs, GPAs, and selectivity indices in the previous example were weighted equally, the resulting linear composite correlated .48 with later faculty rating. Not only is the correlation of this linear composite higher than that with the clinical judgment of the admissions committee (.19), it is also higher than that obtained upon cross-validating the weights obtained from half the sample. An example of an improper model that might be of somewhat more interest—at least to the general public—was motivated by a physician who was on a panel with me concerning predictive systems. Afterward, at the bar with his' wife and me, he said that my paper might be of some interest to my colleagues, but success in graduate school in psychology was not of much general interest: "Could you, for example, use one of your improper linear models to predict how well my wife and I get along together?" he asked. I realized that I could—or might. At that time, the Psychology Department at the University of Oregon was engaged in sex research, most of which was behavioristically oriented. So the subjects of this research monitored when they made love, when they had fights, when they had social engagements (e.g., with in-laws), and so on. These subjects also made subjective ratings about how happy they were in their marital or coupled situation. I immediately thought of an improper linear model to predict self-ratings of marital happiness: rate of lovemaking minus rate of fighting. My colleague John Howard had collected just such data on couples when he was an undergraduate at the University of Missouri—Kansas City, where he worked with Alexander (1971). After establishing the intercouple reliability of judgments of lovemaking and fighting, Alexander had one partner from each of 42 couples monitor these events. She allowed us to analyze her data, with the following results: "In the thirty happily married ^This index was based on Cass and Birnbaum's (1968) rating of selectivity given at the end of their book Comparative Guide to American Colleges. The verbal categories of selectivity were given numerical values according to the following rale: most selective, 6; highly selective, 5; very selective (+), 4; very selective, 3; selective, 2 ; not mentioned, 1. Unfortunately, only 23 of the 111 students could be used in this comparison because the rating scale the admissions committee used changed slightly from year to year. 572 • JULY 1979 • AMERICAN PSYCHOLOGIST
1,924 citations
Book•
01 Jun 1979TL;DR: Buku ini berkaitan dengan pemahaman terhadap bahasa and tempatnya dalam kehidupan manusia. as mentioned in this paper.
Abstract: Buku ini berkaitan dengan pemahaman terhadap bahasa dan tempatnya dalam kehidupan manusia. Sementara persoalan pokok yang dibahas adalah bagaimana struktur bahasa berperan dalam pengembangan bahasa itu sendiri; seperti misalnya mengenai metodologi, grammar dan fungsi, tentang logika versus bahasa, kasus semantik dan fungsi pragmatik, dll.nLebih jauh, buku ini juga mengkaji bagaimana perubahan bahasa bisa terjadi serta bagaimana keterkaitan bahasa dengan disiplin seperti filogeni dan ontologi.
1,328 citations
TL;DR: The hippocampal cortex has the capacity for chunking, but the hippocampal (limbic) arousal system plays a critical role in this chunking process by differentiall y priming (partially activating) free, as opposed to bound, neurons as discussed by the authors.
Abstract: Horizontal versus vertical associative memory concepts are denned. Vertical associative memory involves chunking: the specification of new (previously free) nodes to represent combinations of old (bound) nodes. Chunking is the basis of semantic memory, configuring in conditioning, and cognitive (as opposed to stimulus-response) learning. The cortex has the capacity for chunking, but the hippocampal (limbic) arousal system plays a critical role in this chunking process by differentiall y priming (partially activating) free, as opposed to bound, neurons. Binding a neuron produces negatively accelerated repression of its connections to the hippocampal arousal system, consolidating the memory by protecting the newly bound neuron from diffuse hippocampal input and thus retarding forgetting. Disruption of the hippocampal arousal system produces the amnesic syndrome of an inability to do new chunking (cognitive learning)—anterograde amnesia—and an inability to retrieve recently specified chunks—retrograde amnesia.
454 citations
TL;DR: Support is provided for an analogue movement of attention across the visual field that does not involve the suppression found during saccades by reports that these shifts of attention can be time locked to a central cue.
Abstract: Several experiments have shown that attention as measured by simple reaction time to luminance increments can be shifted in the visual field while the eyes are kept in a fixed position. The shift of attention appears to take place within 50 msec following a cue indicating the most likely position of the target. The present study reports that these shifts of attention can be time locked to a central cue. Moreover, they show that a probe event located between the cue and the target receives maximal facilitation from attention at a time prior to maximal facilitation at the target. These results provide support for an analogue movement of attention across the visual field that does not involve the suppression found during saccades.
396 citations
TL;DR: In this paper, the Drell-Yan parton model for the high-energy process p+p→μ++μ−++X for dimuons with large invariant mass is studied in the case that the protons are polarized.
380 citations
TL;DR: The authors examined the effects of stereotypic expectancies on memory for behavioral events that confirm or disconfirm these expectancies, and concluded that subjects' superior recall of expectancy-confirming events may account for the selfperpetuating character of social stereotypes.
334 citations
Abstract: This study sought to (1) develop a comprehensive typology for interpreting and analyzing organizational environments, (2) empirically test the validity of the typology, and (3) examine the relation...
297 citations
TL;DR: The three-dimensional structure of a water-soluble bacteriochlorophyll a -containing protein from the green photosynthetic bacterium Prosthecochloris aestuarii has been determined by X-ray crystallography from a 2.8 A resolution electron density map based on four isomorphous derivatives.
267 citations
TL;DR: In this paper, Auger and Coster-Kronig transition probabilities have been calculated from perturbation theory for frozen orbitals, in the Dirac-Hartree-Slater approach.
253 citations
TL;DR: The ability of sir1-1 to supply all functions necessary for mating and sporulation and its effects in a cells are explained by proposing that Sir ("Silent-information regulator"), whose role may be to regulate expression of HMa and HM alpha, is defective in a function.
Abstract: A mutation has been identified that suppresses the mating and sporulation defects of all mutations in the mating-type loci of S. cerevisiae. This suppressor, sir1-1, restores mating ability to mat alpha 1 and mat alpha 2 mutants and restores sporulation ability to mat alpha 2 and mata1 mutants. MATa sir1-1 strains exhibit a polar budding pattern and have reduced sensitivity to alpha-factor, both properties of a/alpha diploids. Furthermore, sir1-1 allows MATa/MATa, mat alpha 1/mat alpha/, and MAT alpha/MAT alpha strains to sporulate efficiently. All actions of sir1-1 are recessive to SIR1. The ability of sir1-1 to supply all functions necessary for mating and sporulation and its effects in a cells are explained by proposing that sir1-1 allows expression of mating type loci which are ordinarily not expressed. The ability of sir1-1 to suppress the mat alpha 1-5 mutation is dependent on the HMa gene, previously identified as required for switching of mating types from a to alpha. Thus, as predicted by the cassette model, HMa is functionally equivalent to MAT alpha since it supplies functions of MAT alpha. We propose that sir1-1 is defective in a function. Sir ("Silent-information regulator"), whose role may be to regulate expression of HMa and HM alpha.
TL;DR: The data support the conclusion that foot orthotic devices can be successfully used to modify selected aspects of lower extremity mechanics during the sup port phase of running.
Abstract: Excessive foot pronation has been speculated to be a cause of leg and foot problems among runners. Foot orthotic devices are often used to modify this condition. Examination of the records of 180 patients treated for various running injuries showed that 83 individuals (46%) were prescribed orthotic devices and that 65 of these runners (78%) were able to return to their previous running programs. In order to assess further the effects of this type of orthotic device, six runners were selected from this group and filmed using two cameras (200 frames/sec) under three conditions: (1) barefoot, (2) regular shoe, and (3) regular shoe plus orthotic device. Both the period of pronation and the amount of maximum pronation were significantly reduced by using the foot orthotic device. The data support the conclusion that foot orthotic devices can be successfully used to modify selected aspects of lower extremity mechanics during the support phase of running.
TL;DR: The structure of a temperature sensitive (ts) mutant of T4 phage lysozyme is reported, allowing the first direct comparison of two protein structures in which all differences are directly related to a change in thermal stability.
Abstract: MOST proteins are denatured at temperatures above 50–60°C, although some enzymes, especially those from thermophilic organisms, remain active at temperatures up to 80–90 °C The determination of the three-dimensional structure of the thermostable protease thermolysin showed that heat-stable proteins do not contain unusual structural features absent from less stable proteins1,2 Furthermore, the amino acid sequences of similar proteins from both mesophilic and thermophilic sources have been shown to be homologous, suggesting that the respective structures are similar3,4 Nevertheless, such homologous amino acid sequences also include many differences which obscure those amino acid changes actually responsible for differences in thermostability We report here the structure of a temperature sensitive (ts) mutant of T4 phage lysozyme This permits the first direct comparison of two protein structures in which all differences are directly related to a change in thermal stability It is shown that, except for the replacement of a partially exposed arginine by a histidine, the three-dimensional structure of the ts lysozyme is virtually identical with that of native lysozyme
TL;DR: It appears that the yields of other extracellular products of P. aeruginosa besides toxin A are influenced by the concentration of iron in the growth medium, and this hemagglutinin was nondialyzable, heat stable, and resistant to Pronase and trypsin.
Abstract: The effect of the iron content of the medium on the yields of extracellular products by seven distinct strains of Pseudomonas aeruginosa was examined. All strains showed at least an 85% decrease in toxin A yields when grown in medium containing 5.0 μg of iron per ml (high iron) as compared to 0.05 μg/ml (low iron), whereas bacterial growth increased approximately twofold. During the course of examining extracellular products produced by P. aeruginosa, we found many strains that produced an extracellular factor which agglutinated erythrocytes. This hemagglutinin was nondialyzable, heat stable, and resistant to Pronase and trypsin. The effect of iron on extracellular yields of hemagglutinin was strain dependent; four of seven strains showed decreases in hemagglutinin yields in high-iron medium. Similarly, the effect of increasing the iron concentration of the growth medium on yields of total extracellular proteases or on elastase was strain dependent. The amount of total extracellular protein was decreased by at least 31% in the high-iron medium for all strains of P. aeruginosa examined. Detailed studies on one strain (WR-9) showed that, in the presence of increasing amounts of iron in the medium, the extracellular yields of toxin A, protease, and hemagglutinin were decreased in a similar manner. In addition, the kinetics of release of these extracellular products were similar at a given iron concentration. Thus it appears that the yields of other extracellular products of P. aeruginosa besides toxin A are influenced by the concentration of iron in the growth medium.
TL;DR: A plate assay to measure protease production by Pseudomonas aeruginosa is described, which is more sensitive and rapid than established methods.
Abstract: A plate assay to measure protease production by Pseudomonas aeruginosa is described. This assay is more sensitive and rapid than established methods.
TL;DR: It is demonstrated that Giardia excystation in acidic solutions, the pattern of trophozoite emergence during excy station, and a method for routine in vitro induction of excy Station are demonstrated, and the establishment of in vitro axenic cultures from excysted trophozites are demonstrated.
Abstract: MANY vertebrates, including humans, are hosts for the intestinal protozoan parasite, Giardia. This genus has a worldwide distribution1 and in recent years has become an increasingly important public health problem2–14. Human infections may be associated with intestinal discomfort, diarrhoea, and malabsorption syndromes15–17. The life cycle of Giardia is divided into trophozoite and cyst stages. When the cyst is ingested by the host, excystation occurs (trophozoites emerge) and the upper small intestine is colonised. Although research on Giardia excystation began nearly 50 yr ago18,19, conditions for the induction of the process were never defined. We demonstrate here (1) Giardia excystation in acidic solutions, (2) the pattern of trophozoite emergence during excystation, (3) a method for routine in vitro induction of excystation, and (4) the establishment of in vitro axenic cultures from excysted trophozoites.
TL;DR: The results show that the process of mating type interconversion is itself controlled during growth of a clone of homothallic cells, and propose that multiple cell types can be produced in a specific pattern during development of a higher eucaryote in a model involving sequential cassette insertion.
TL;DR: It is proposed that in the metathoracic ganglion the two extensor tibiae motor neurons have switched functions while retaining similar morphologies relative to the structure and function of their pro- and mesothoracics serial homologues.
Abstract: Twenty-one prothoracic and 17 mesothoracic motor neurons innervating leg muscles have been identified physiologically and subsequently injected with dye from a microelectrode. A tract containing the primary neurites of motor neurons innervating the retractor unquis, levator and depressor tarsus, flexor tibiae, and reductor femora is described. All motor neurons studied have regions in which their dendritic branches overlap with those of other leg motor neurons. Identified, serially homologous motor neurons in the three thoracic ganglia were found to have: (1) cell bodies at similar locations and morphologically similar primary neurites (e.g., flexor tibiae motor neurons), (2) cell bodies at different locations in each ganglion and morphologically different primary neurites in each ganglion (e.g., fast retractor unguis motor neurons), or (3) cell bodies at similar locations and morphologically similar primary neurites but with a functional switch in one ganglion relative to the function of the neurons in the other two ganglia. As an example of the latter, the morphology of the metathoracic slow extensor tibiae (SETi) motor neurons was similar to that of pro- and mesothoracic fast extensor tibiae (FETi) motor neurons. Similarly the metathoracic FETi bears a striking resemblance to the pro- and the mesothoracic SETi. It is proposed that in the metathoracic ganglion the two extensor tibiae motor neurons have switched functions while retaining similar morphologies relative to the structure and function of their pro- and mesothoracic serial homologues.
TL;DR: In this article, the energy spectrum of an electron in the presence of a uniform magnetic field and a potential of hexagonal symmetry is analyzed, and two alternative approaches are used, one that takes as a basis set free-electron Landau functions, and a second one that treats an effective single-band Hamiltonian with the Peierls substitution.
Abstract: The energy spectrum of an electron in the presence of a uniform magnetic field and a potential of hexagonal symmetry is analyzed. Two alternative approaches are used, one that takes as a basis set free-electron Landau functions, and a second one that treats an effective single-band Hamiltonian with the Peierls substitution. Both methods lead to consistent results. The energy spectrum is found to have recursive properties similar to those discussed by Hofstadter for the case of a square lattice. The density of states over each subband of the spectrum has the same structure as that for the original field-free band. The plot of integrated density of states versus field is also discussed.
TL;DR: In this paper, the authors constructed a psychometrically sound instrument for the measurement of aversive events and tested hypotheses about the occurrence of such events and depression in a group of participants.
Abstract: The goal was to construct a psychometrically sound instrument for the measurement of aversive events. Hypotheses about the occurrence of aversive events and depression were also tested. The Un plea...
TL;DR: Temperature, pH, time, and incubation medium were shown to affect the levels of excystation achieved and those conditions most closely approximating the organism's in vivo environment induced the highest levels ofExcystation.
TL;DR: The inverse relationship of spontaneous blinking rate and number of blink reflexes to habituation in early childhood and in disorders of dopamine transmission suggests that spontaneous blink rate and habituation of the blink reflex reflect maturation and integrity of dopaminergic circuits in the brain.
Abstract: Habituation of the blink reflex to glabellar percussion was examined in 164 infants and children from ages 2 days to 18 years and in 18 adults aged 18 to 50 years. Spontaneous blink rates were measured in 269 children and 179 adults. The mean number of glabellar taps required for habituation of the blink reflex increased from 2.7 (SD 1.2) at 0 to 2 months of age to a peak of 13.3 (SD 5.6) at age 3 to 4, remained at more than 10 until age 6, after which a rapid decline occurred, reaching the adult level of 2 to 5 blinks to habituation at age 12 years. The mean rate of spontaneous blinking was less than 2 per minute in early infancy and increased steadily during childhood up to age 14 or 15. The inverse relationship of spontaneous blink rate and number of blink reflexes to habituation in early childhood and in disorders of dopamine transmission suggests that spontaneous blink rate and habituation of the blink reflex reflect maturation and integrity of dopaminergic circuits in the brain.
TL;DR: Genetic and physical characterization of rearrangements of chromosome III which result in changes of cell type in S. cerevisiae are described and it is suggested this deletion removes MATalpha and activates cryptic MATa information stored in HMalpha as proposed in the cassette model of mating type interconversion.
TL;DR: In this article, the electronic structure of the (110) surface of GaAs is analyzed using a surface-relaxation model as determined by recent low-energy-electron diffraction studies.
Abstract: The electronic structure of the (110) surface of GaAs is analyzed using a surface-relaxation model as determined by recent low-energy-electron diffraction studies. A self-consistent pseudopotential calculation based on this model yields no intrinsic surface states within the fundamental band gap: a result not achieved in previous pseudopotential calculations. The calculations appear to be in good accord with recent photoemission measurements and we present an analysis of the surface-state energy spectra. In addition, our studies suggest that pseudopotential calculations coupled with angle-resolved photoemission measurements can be a sensitive probe of surface structural properties.
TL;DR: The cubital tunnel syndrome is a subgroup of ulnar neuropathies arising at the elbow, with nerve entrapment under the aponeurosis connecting the two heads of the flexor carpi ulnaris muscle, to separate it from tardy ulnar palsy.
Abstract: The cubital tunnel syndrome is a subgroup of ulnar neuropathies arising at the elbow, with nerve entrapment under the aponeurosis connecting the two heads of the flexor carpi ulnaris muscle. To separate this condition more clearly from tardy ulnar palsy, the clinical and electrophysiological features of 9 patients are presented, 6 of whom had the syndrome bilaterally. There was no history of trauma and no clinical or roentgenographic evidence of joint deformity in any of the patients. In 9 of the 15 ulnar nerves, abnormal conduction was localized to the level of the cubital tunnel (1.5 to 3.5 cm distal to the medial epicondyle). The findings were confirmed intraoperatively in 7 patients and corresponded to a tight band compressing the ulnar nerve and causing narrowing at the cubital tunnel with swelling proximally. This syndrome represents a common and distinct subgroup of ulnar neuropathies at the elbow.
TL;DR: It is concluded that under the conditions used, juvenile hormone permits vitellogenin uptake into the oocyte much more readily than does 20-hydroxy-ecdysone.