Cluster versus POTENT Density and Velocity Fields: Cluster Biasing and Omega

The density and velocity fields as extracted from the Abell/ACO clusters are compared to the corresponding fields recovered by the POTENT method from the Mark~III peculiar velocities of galaxies. In order to minimize non-linear effects and to deal with ill-sampled regions we smooth both fields using a Gaussian window with radii ranging between 12 - 20\hmpc. The density and velocity fields within 70\hmpc exhibit similarities, qualitatively consistent with gravitational instability theory and a linear biasing relation between clusters and mass. The random and systematic errors are evaluated with the help of mock catalogs. Quantitative comparisons within a volume containing $\sim\!12$ independent samples yield \betac\equiv\Omega^{0.6}/b_c=0.22\pm0.08, where $b_c$ is the cluster biasing parameter at 15\hmpc. If $b_c \sim 4.5$, as indicated by the cluster correlation function, our result is consistent with $\Omega \sim 1$.Comment: 18 pages, latex, 2 ps figures 6 gif figures. Accepted for pubblications in MNRA

Training People to Think in Opposites Facilitates the Falsification Process in Wason’s Rule Discovery Task

With reference to Wason’s 2-4-6 rule discovery task, this study investigated the effects of a simple training session that prompted participants to “think in opposites”. The results showed a significant improvement in performance under the training condition when compared to the control condition, both in terms of the proportion of participants who discovered the correct rule and how quickly it was discovered. An analysis of whether or not participant submitted test triples formed of descending numbers showed that fewer participants under the control condition considered ascending/descending to represent a critical dimension and, in any case, this occurred later (that is, after more test triples) than in the training condition. These results are discussed in relation to previous literature showing improvements in performance that were prompted by strategies involving “contrast” as a critical factor. The limitations of the study are discussed, as well as the benefits of a training program like this, which is non-content related

Opposites in reasoning processes: do we use them more than we think, but less than we could?

Our aim in this paper is to contribute toward acknowledging the general role of opposites as an organizing principle in the human mind. We support this claim in relation to human reasoning by collecting evidence from various studies which shows that \u201cthinking in opposites\u201d is not only involved in formal logical thinking, but can also be applied in both deductive and inductive reasoning, as well as in problem solving. We also describe the results of a series of studies which, although they have been developed within a number of different theoretical frameworks based on various methodologies, all demonstrate that giving hints or training reasoners to think in terms of opposites improves their performance in tasks in which spontaneous thinking may lead to classic biases and impasses. Since we all possess an intuitive idea of what opposites are, prompting people to \u201cthink in opposites\u201d is something which is undoubtedly within everyone's reach and in the final section, we discuss the potential of this strategy and suggest possible future research directions of systematic testing the benefits that might arise from the use of this technique in contexts beyond those tested thus far. Ascertaining the conditions in which reasoners might benefit will also help in terms of clarifying the underlying mechanisms from the point of view, for instance, of analytical, conscious processing vs. automatic, unconscious processing

A che punto siamo con le ricerche sui contrari?

After considering the pervasiveness of same/different relationships in Psychology and the experimental evidence of their perceptual foundation in Psychophysics and Infant and Comparative Psychology, this paper develops its main argument. Similarity and diversity do not complete the panorama since opposition constitutes a third relationship which is distinct from the other two. There is evidence of this in the previous literature investigating the perceptual basis of opposition and in the results of the two new studies presented in this paper. In these studies, the participants were asked to indicate to what extent pairs of simple bi-dimensional figures appeared to be similar, different or opposite to each other. A rating task was used in Study 1 and a pair comparison task was used in Study 2. Three main results consistently emerged: Firstly, opposition is distinct from similarity and difference which, conversely, are in a strictly inverse relationship. Secondly, opposition is specifically linked to something which points in an allocentrically opposite direction. Thirdly, alterations to the shape of an object are usually associated with the perception of diversity rather than opposition. The implications of a shift from a dyadic (same/different) to a triadic (similar/different/opposite) paradigm are discussed in the final section

Comprensione da parte dei non esperti dei termini frequentemente utilizzati dagli esperti per descrivere proprietà sensoriali del vino: un'indagine basata sui contrari

Expert wine tasters have a greater ability than non-experts to discriminate between and evaluate the sensory properties of wine. In this paper we explore non-experts’ understanding of a set of 64 terms which are frequently used as descriptors of the sensory properties of wine. These terms can be found in guidebooks on Italian wine, in production specifications and in the official tasting scales of the Italian Sommelier Association. The 64 target terms were selected in a preliminary phase of Study 1. These terms were then presented to 558 Italian non-expert consumers who were asked to identify the opposite of each target term, in relation to red and white wines respectively. The findings a) suggest that non-experts are able to think of the sensorial properties of wine in terms of dimensions modeled by two opposite poles (and it is interesting to note that this is in line with the bipolar structure of many dimensions used by experts); b) made it possible to identify the properties that are consistently associated by non-experts with the same dimension and those which, in contrast, evoke different opposites (i.e. the underlying dimension is less univocal) and c) reveal that the target properties generally evoke similar dimensions when applied to both red and white wines. In Study 2, the gap between the experts’ interpretation of the terms and that of the non-experts was explored. Taken as a whole, the results of the study indicate an empirical methodology that may be used to investigate how standard consumers understand descriptions of wine. They may also provide food for thought regarding the ambiguity embedded in these descriptions due to potential discrepancies between the lexicons that experts and non-experts refer to in the world of wine tasting

The role of training or hints relating to \u201cthinking in opposites\u201d in insight problem solving

In recent years, there has been a growing desire to remove the mystery from insight, the underlying processes of which are not fully understood (Gilhooly et al., 2015). The present research focuses on the hypothesis that \u201cthinking in opposites\u201d might facilitate the process of representational change required for solving visuo-spatial insight problems (Bianchi et al., 2019; Branchini et al., 2015, 2016). There is evidence in Cognitive Science that opposites (or contrasts) are a central cognitive structure in space perception (e.g. Bianchi et al., 2017) and language (e.g. Jones et al., 2012) and they are fundamental to inductive (Gale and Ball, 2012) and deductive reasoning (Augustinova, 2008). They are also involved in creative thinking (Rothenberg, 2001). In particular, the study reports the results of research carried out with the aim of investigating whether prompting problem solvers to use a strategy based on the manipulation of opposites (i.e. inside-outside, large-small) would improve their performance (Bianchi et al., 2019). Two hundred and forty undergraduate students were asked to analyze the spatial features inherent to six problems in terms of opposites before embarking on their search for a solution. Two hint and two training conditions were studied. The results show that success rates increased when the participants were explicitly trained to use opposites. In relation to the current debate on the factors which facilitate insight problem solving (e.g. Ahmed and Patrick, 2006; Cunningham and MacGregor, 2008; Patrick et al., 2015), our results add evidence that a prompt \u201cto think in opposites\u201d is a facilitating factor when it is given explicitly (i.e. as part of training). The findings are also discussed in relation to a debate on the same subject regarding the differences between the role of Type 1 processes (which are automatic, unconscious and associative) and that of Type 2 processes (which are controlled, conscious and analytical) (e. g. Weisberg, 2015, 2018). In particular, we provide suggestions concerning the nature of the role of opposites in the generation of potential solutions (Type 1 processes) and in the evaluation of these various potential alternatives with a view to homing in on a single solution (Type 2 processes)

The Bulk Motion of Flat Edge-On Galaxies Based on 2MASS Photometry

We report the results of applying the 2MASS Tully-Fisher (TF) relations to study the galaxy bulk flows. For 1141 all-sky distributed flat RFGC galaxies we construct J, H, K_s TF relations and find that Kron $J_{fe}$ magnitudes show the smallest dispersion on the TF diagram. For the sample of 971 RFGC galaxies with V_{3K} < 18000 km/s we find a dispersion $\sigma_{TF}=0.42^m$ and an amplitude of bulk flow V= 199 +/-61 km/s, directed towards l=301 degr +/-18 degr, b=-2 degr +/-15 degr. Our determination of low-amplitude coherent flow is in good agreement with a set of recent data derived from EFAR, PSCz, SCI/SCII samples. The resultant two- dimensional smoothed peculiar velocity field traces well the large-scale density variations in the galaxy distributions. The regions of large positive peculiar velocities lie in the direction of the Great Attractor and Shapley concentration. A significant negative peculiar velocity is seen in the direction of Bootes and in the direction of the Local void. A small positive peculiar velocity (100 -- 150 km/s) is seen towards the Pisces-Perseus supercluster, as well as the Hercules - Coma - Corona Borealis supercluster regions.Comment: 10 pages, 5 figures. A&A/2003/3582 accepted 15.05.200

Galaxy and Cluster Biasing from Local Group Dynamics

Comparing the gravitational acceleration induced on the Local Group of galaxies by different tracers of the underline density field we estimate, within the linear gravitational instability theory and the linear biasing ansatz, their relative bias factors. Using optical SSRS2 galaxies, IRAS (PSCz) galaxies and Abell/ACO clusters, we find b_{O,I} ~ 1.21 +- 0.06 and b_{C,I} ~ 4.3 +- 0.8, in agreement with other recent studies. Finally, there is an excellent one-to-one correspondence of the PSCz and Abell/ACO cluster dipole profiles, once the latter is rescaled by b_{C,I}, out to at least ~150 h^{-1} Mpc.Comment: 7 pages, 5 figures, accepted for publication in MNRA

The Hubble flow around the Local Group

We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < D_LG < 3.0 Mpc, the Local flow is characterized by the Hubble parameter H_loc = (78+/-2) km/(s*Mpc), the mean-square peculiar velocity sigma_v = 25 km/s, corrected for errors of radial velocity measurements (~4 km/s) and distance measurements (~10 km/s), as well as the radius of the zero-velocity surface R_0 = (0.96+/-0.03) Mpc. The minimum value for sigma_v is achieved when the barycenter of the LG is located at the distance D_c = (0.55+/-0.05) D_M31 towards M31 corresponding to the Milky Way-to-M31 mass ratio M_MW / M_M31 ~ 4/5. In the reference frame of the 30 galaxies at 0.7 - 3.0 Mpc, the LG barycenter has a small peculiar velocity ~(24+/-4) km/s towards the Sculptor constellation. The derived value of R_0 corresponds to the total mass M_T(LG) = (1.9+/-0.2) 10^12 M_sun with Omega_m = 0.24 and a topologically flat universe, a value in good agreement with the sum of virial mass estimates for the Milky Way and M31.Comment: 14 pages, 6 figures, 1 table. Accepted for publication in MNRA