A practical guide and software for analysing pairwise comparison experiments

Most popular strategies to capture subjective judgments from humans involve the construction of a unidimensional relative measurement scale, representing order preferences or judgments about a set of objects or conditions. This information is generally captured by means of direct scoring, either in the form of a Likert or cardinal scale, or by comparative judgments in pairs or sets. In this sense, the use of pairwise comparisons is becoming increasingly popular because of the simplicity of this experimental procedure. However, this strategy requires non-trivial data analysis to aggregate the comparison ranks into a quality scale and analyse the results, in order to take full advantage of the collected data. This paper explains the process of translating pairwise comparison data into a measurement scale, discusses the benefits and limitations of such scaling methods and introduces a publicly available software in Matlab. We improve on existing scaling methods by introducing outlier analysis, providing methods for computing confidence intervals and statistical testing and introducing a prior, which reduces estimation error when the number of observers is low. Most of our examples focus on image quality assessment.Comment: Code available at https://github.com/mantiuk/pwcm

Educational Attainment and Risk Preference

We explore the relationship between risk preference and educational attainment for a sample of adults drawn from the 1996 U.S. Panel Study of Income Dynamics (PSID). Using a sequence of questions from the 1996 PSID, we construct measures of an individual´s risk aversion and risk tolerance allowing us to explore the implications of interpersonal differences in risk preference for educational attainment. Our empirical findings suggest that an individual´s degree of risk aversion (tolerance) is inversely (positively) associated with their educational attainment. In addition, using the 1997 and 2002 Child Development Supplements of the PSID, we explore the relationship between the risk preference of parents and the academic achievements of their children. Our findings suggest that a parent´s degree of risk aversion (tolerance) is negatively (positively) related to the academic achievements of their children

Educational loans and attitudes towards risk

We explore the relationship between willingness to take financial risk and the probability of taking out a loan for educational purposes as well as the influence of risk attitudes on the size of the loan using data drawn from the U.S. Survey of Consumer Finances. The findings suggest a positive relationship between individuals’ willingness to take financial risk and the probability of taking out a loan for educational purposes. Similarly, individuals’ willingness to take financial risk appears to be an important determinant of the size of the educational loan. The findings suggest that non-white individuals and individuals from less wealthy backgrounds are less likely to finance education through loans which could potentially increase inequalities in education and income if such individuals are deterred from investing in human capital

Four keys to Chilean culture : authoritarianism, legalism, fatalism and compadrazgo

Chilean culture is said to be part of a wider Hispanic American culture that shares many traits (see Godoy et al. 1986; Subercaseaux 1999; Valdivieso and which could be identified as an identity with a Latin American sense (see Rodríguez et al. 2001). In this sense, though it may seem as if any attempt to describe or analyse particular operating elements, processes, systems and structures were a useless task, the nature of identity makes it a multiple and symbolically contradictory phenomenon, with relevant contextual 'consequences' and particularities that help identify a collective imaginary that can be associated with what means to be Chilean. As such, the importance of meaning lies not on its production but rather on its reception; therefore, we aim to address some elements of the reception that we have identified as 'critical' or 'diagnostic'. By 'critical', we mean those elements, which absence would substantively modify what is collectively associated with Chilean culture and by 'diagnostic', we suggest the possibility they offer of exploring meaningful contextual traits. In order to contextualise our analysis, we will focus on three discursive levels, namely organisational/structural, cultural/ideological and identity. At the organisational/structural level, we will make reference to structure and aesthetics in the broader sense of social context as well as in public and private organisations; at cultural/ideological level, we will make reference to practices, rituals, values and behaviours; and at the identity level we will make reference to strategies individuals use to manage their social identities

Game Transfer Phenomena in video game playing: a qualitative interview study

Video game playing is a popular activity and its enjoyment among frequent players has been associated with absorption and immersion experiences. This paper examines how immersion in the video game environment can influence the player during the game and afterwards (including fantasies, thoughts, and actions). This is what we describe as Game Transfer Phenomena (GTP). GTP occurs when video game elements are associated with real life elements triggering subsequent thoughts, sensations and/or player actions. To investigate this further, a total of 42 frequent video game players aged between 15 and 21 years old were interviewed. Thematic analysis showed that many players experienced GTP, where players appeared to integrate elements of video game playing into their real lives. These GTP were then classified as either intentional or automatic experiences. Results also showed that players used video games for interacting with others as a form of amusement, modeling or mimicking video game content, and daydreaming about video games. Furthermore, the findings demonstrate how video games sometimes triggered intrusive thoughts, sensations, impulses, reflexes, optical illusions, and dissociations

A generalized Finch-Skea class one static solution

In the present article, we discuss relativistic anisotropic solutions of the Einstein field equation for the spherically symmetric line element under the class I condition. To do so we apply the embedding class one technique using Eisland condition. Within this approach, one arrives at a particular differential equation that links the two metric components $e^{\nu}$ and $e^{\lambda}$. In order to obtain the full space-time description inside the stellar configuration we ansatz the generalized form of metric component $g_{rr}$ corresponding to the Finch-Skea solution. Once the space-time geometry is specified we obtain the complete thermodynamic description i.e. the matter density $\rho$, the radial, and tangential pressures $p_r$ and $p_t$, respectively. Graphical analysis shows that the obtained model respects the physical and mathematical requirements that all ultra-high dense collapsed structures must obey. The $M-R$ diagram suggests that the solution yields stiffer EoS as parameter $n$ increases. The $M-I$ graph is in agreement with the concepts of Bejgar et al. \cite{bej} that the mass at $I_{max}$ is lesser by few percent (for this solution $\sim 3\%$) from $M_{max}$. This suggests that the EoSs is without any strong high-density softening due to hyperonization or phase transition to an exotic state.Comment: 14 figures, Accepted in European Physical Journal

Rotational properties of the binary and non-binary populations in the Trans-Neptunian belt

We present results for the short-term variability of Binary Trans-Neptunian Objects (BTNOs). We performed CCD photometric observations using the 3.58 m Telescopio Nazionale Galileo, the 1.5 m Sierra Nevada Observatory telescope, and the 1.23 m Centro Astronomico Hispano Aleman telescope at Calar Alto Observatory. We present results based on five years of observations and report the short-term variability of six BTNOs. Our sample contains three classical objects: 2003MW12, or Varda, 2004SB60, or Salacia, and 2002 VT130; one detached disk object: 2007UK126; and two resonant objects: 2007TY430 and 2000EB173, or Huya. For each target, possible rotational periods and/or photometric amplitudes are reported. We also derived some physical properties from their lightcurves, such as density, primary and secondary sizes, and albedo. We compiled and analyzed a vast lightcurve database for Trans-Neptunian Objects (TNOs) including centaurs to determine the lightcurve amplitude and spin frequency distributions for the binary and non-binary populations. The mean rotational periods, from the Maxwellian fits to the frequency distributions, are 8.63+/-0.52 h for the entire sample, 8.37+/-0.58 h for the sample without the binary population, and 10.11+/-1.19 h for the binary population alone. Because the centaurs are collisionally more evolved, their rotational periods might not be so primordial. We computed a mean rotational period, from the Maxwellian fit, of 8.86+/-0.58 h for the sample without the centaur population, and of 8.64+/-0.67 h considering a sample without the binary and the centaur populations. According to this analysis, regular TNOs spin faster than binaries, which is compatible with the tidal interaction of the binaries. Finally, we examined possible formation models for several systems studied in this work and by our team in previous papers.Comment: Accepted for publication in Astronomy and Astrophysics (June 26th, 2014); minor changes with published version; 21 pages, 17 figures, 7 table

The gaseous extent of galaxies and the origin of Lyman alpha absorption systems. IV: Lyman alpha absorbers arising in a galaxy group

We present new GHRS observations of Lyman alpha absorption lines associated with a group of galaxies towards the QSO 1545+2101. We have identified eight distinct Lyman alpha absorption features in the spectrum of QSO 1545+2101 at a mean redshift of z=0.2648 with a velocity dispersion of 163 km/s. A group of galaxies is detected in the vicinity of this QSO at a mean redshift of z=0.2645 and velocity dispersion 239 km/s. The identification of discrete absorption systems indicates that they arise in clouds of neutral hydrogen rather than in a diffuse intragroup medium. Our analysis suggests that the Lyman alpha absorption lines are associated with individual galaxies in the group, although a one-to-one relationship between absorbers and galaxies is difficult to establish in such a dense environment.Comment: 16 pages, 3 figures. Accepted for publication in Ap