On the Classification of Colored Textures From a Texture-Ranking Experiment: Observers Ability of Discrimination Quantification

This paper is devoted to the construction of Fechnerian scales on a physical dimension of investigated colored textures. For this purpose, we considered the extension of the Mallows-Bradley-Terry model for the analysis of the data collected from a contrast-sorting experiment. A likelihood ratio test procedure was proposed in order to choose between the two following hypotheses: discrimination and non-discrimination between the investigated stimuli. In addition, post-hoc analyzes allowed us to find out which of the stimuli differ from the others. Our findings indicate that the subjective attribute of visual contrast appears to be a psycho physical scale that maps to the physical scale corresponding to the Michelson contrast. Mainly, the estimates of the model index of discrimination parameter of the stimuli show that the ability of the observers to discriminate between the textures according to the visual contrast varies with respect to the color ranges and the textures types. According to the luminance contrasts ability of discrimination, the Isotropic texture type is the best, followed by the Random-dots texture type, then by the Horizontal grating type and the Vertical grating type is the least. The Fechnerian scales on the physical dimension of the Michelson contrast of the colored textures depend on the chromaticness of the colored textures phases and the texture types. The psycho physical method of identification would be the best when determining the related thresholds.

What Are the Core Features of Psychopathy? A Prototypicality Analysis Using the Psychopathy Checklist-Revised (PCL-R)

What are the core features of psychopathy? Previous prototypicality analyses showed that many features were considered as highly prototypical. The authors extend this work by using forced ranking to grasp which features are most important. Forensic mental health professionals ranked the 20 Psychopathy Checklist-Revised (PCL-R) items on their importance to psychopathy. Affective-interpersonal features were judged to be of greater importance than behavioral–lifestyle features. The most important items were callous/lack of empathy, conning/manipulative, and lack of remorse or guilt, which were deemed more important than nearly all other PCL-R features. The prototypicality ranking of the 20 PCL-R items by the forensic mental health professionals showed strong overlap (r = .64 to .86) with psychometric indices of item importance (network centrality, item-total correlation, and item response theory discrimination parameter). Taken together, these findings clarify the relative importance of PCL-R features to psychopathy.

On the rock-physics basis for seismic hydrocarbon detection

One of the primary fluid indicators for direct hydrocarbon detection in sandstones using seismic reflectivity is the difference between the saturated-rock P-wave impedance and the rock-frame impedance. This can be expressed in terms of the difference between the observed P-wave impedance squared and a multiplier times the square of the observed S-wave impedance. This multiplier is a fluid discrimination parameter that laboratory and log measurements suggest varies over a wide range. Theoretically, this parameter is related to the ratio of the frame bulk and shear moduli and the ratio of the frame and fluid-saturated rock densities. In practice, empirical determination of the fluid discrimination parameter may be required for a given locality. Given sufficient data for calibration, the parameter can be adjusted so as to best distinguish hydrocarbon-saturated targets from brine-saturated rocks. Using an empirically optimized fluid discrimination parameter has a greater impact on hydrocarbon detection success rate in the oil cases studied than for gas reservoirs, for which there is more latitude. Application to a wide variety of well-log and laboratory measurements suggests that the empirically optimized parameter may differ from direct theoretical calculations made using Gassmann’s equations. Combining laboratory and log measurements for sandstones having a broad range of frame moduli, varying from poorly consolidated to highly lithified, reveals a simple linear empirical relationship between the optimized fluid discrimination parameter and the squared velocity ratio of brine-saturated sandstones.

Asymmetry Analysis of the Resonance Curve in Resonant Integrated Optical Gyroscopes

The Resonant Integrated Optic Gyroscope (RIOG) is a type of high accuracy gyroscope based on the Sagnac effect. A symmetrical resonance curve is very important to the performance of the RIOG. To further investigate and design a RIOG with a waveguide ring resonator, an in-depth research of the asymmetric resonance curve and its influence on the RIOG is fully developed. Four possible optical noises inducing the resonance curve asymmetry are analyzed and their mathematic models are established. These four optical noises are the normal mode effect, the backscattering noise, the backreflection noise and the polarization noise. Any asymmetry of the resonance curve will not only induce a large output bias error into the gyro output, but also seriously decrease the frequency discrimination parameter of the demodulation curve. By using a tunable fiber laser, the high aspect ratio silicon nitride WRR and the silicon dioxide WRR were tested. The experiment measured resonance curves can be well fitted with the theoretical simulation results. The experimental results show that a high aspect ratio silicon nitride waveguide can effectively suppress the polarization noise in the RIOG.

Using Item Response Theory to Evaluate Self-directed Learning Readiness Scale

Item Response Theory becomes one of the most popular methods for instruments development and evaluation methods. This baseline study is a self-directed learning readiness (SDLR) 40 item scale with data from 648 undergraduate psychology female students attending Qassim University in Saudi Arabia through randomized selection to evaluate an SDLR scale at item and scale levels using GRM. Results provide more detailed diagnostic information to modulate the scale. GRM analysis led to the detection of two locally dependent items, one item with low discrimination parameter and 15 model misfit items. The scale often tends to measure low and moderate levels of SDLR. Advanced psychometric evaluations should be made and the SDLR scale must be reviewed based on quantitative and qualitative analysis.

What are the core features of psychopathy? A prototypicality analysis using the Psychopathy Checklist-Revised (PCL-R)

What are the core features of psychopathy? Previous prototypicality analyses showed that many features were considered as highly prototypical. We extend this work by using forced ranking to grasp which features are most important. Forensic mental health professionals ranked the 20 Psychopathy Checklist-Revised (PCL-R) items on their importance to psychopathy. Affective-interpersonal features were judged to be of greater importance than behavioral-lifestyle features. The most important items were callous/lack of empathy, conning/manipulative, and lack of remorse or guilt, which were deemed more important than nearly all other PCL-R features. The prototypicality ranking of the 20 PCL-R items by the forensic mental health professionals showed strong overlap (r = .64 to .86) with psychometric indices of item importance (network centrality, item-total correlation, and IRT discrimination parameter). Taken together, our findings clarify the relative importance of PCL-R features to psychopathy.

Assessment of intertemporal preferences in type-2 diabetes patients and smokers

The experiment assesses the role of cortisol concentration on bloodstream as correlate of the intertemporal choice and temporal discrimination in Type-2 Diabetes Mellitus (T2DM) patients and smokers. The participants were evaluated in a two independent computerized tasks allowed to obtain the temporal discount function and it’s hyperbolic decay parameter (k), which refers to the tendency to discount the subjective value of future goods as a function of the delay to receiving them; and a temporal discrimination index (bisection point), this function relate the response proportion of “Long” stimuli with probe duration. The bisection point is the value at which responses to Short and Long stimuli occur with equal frequency. We analysed both parameters, then a comparisons of the temporal discount parameter[F(2,147) =79.858,p<,01]and time discrimination parameter[F(2,147) =49,51,p<,01]revealed statistically significant differences between control group and T2DM and smokers groups. We concluded that the choice for delayed rewards and the temporal discrimination of T2DM patients and smokers were influenced by the cortisol concentration in the bloodstream; the higher the concentration of cortisol in the bloodstream, the higherthe likelihood to choose immediate rewards over larger delayed rewards and the higher the tendency tooverestimate the passage of time. We propose to investigate the effects of salivary cortisol elevation levels through noninvasive pharmacologically induction on healthy adult humans, to extend the research line that assess the direct influence over intertemporal choice and temporal discrimination to increase the effect generality.

PEMILIHAN BUTIR SOAL PADA RANCANGAN TES ADAPTIF BERDASARKAN EFFICIENCY BALANCED INFORMATION

One of the most popular item selection methods in the design of adaptive testing is Maximum Information Method. This method provides the items with the maximum information at a certain level of selecting ability. The lack of this method is rarely accurate in estimating the level of ability of the examinees at the beginning of the test and tends to select items with higher discrimination-parameter value than items with lower discrimination-parameter. It creates problem in maintaining item bank. Therefore, another method should be found. The objective of the study is to determine the performance of the application of the estimation method Balanced Efficiency Information (EBI) on the design of an adaptive test. This research was carried out through a simulation study in the setting of organizing the Open University final exams. Item bank for the purposes of simulation models based on 3 parameters Item Response Theory was contructed a total of 900 items were generated base on the ideal parameter of the item specifications. Two selection criteria items were simulated, namely Information Maximum and EBI Maximum. Those two criteria were also designed to meet the content balancing. This is to ensure that the algorithm is appropriate with the applicable UT modular learning, meaning items of each module were proportionally represented and suited the blueprint. The tests will be stopped at when the standard error of estimate ( standard error of estimation = SEE ) is 0.3.The study summarized that the algorithm of EBI was more accurate than the Maximum Information criteria in estimating performance capabilities of participants. This is indicated by the value of the bias and the standard deviation of EBI is smaller than Maximum Information criterias. Another advantage of the application of the EBI Maximum is optimally utilizing of the item bank. The items with low level of the discrimination-parameter will also be chosen at the begining of the test. The maximum information criterion is more efficient in terms of test length but less optimally of the item bank utilization. Salah satu metode pemilihan butir soal yang popular digunakan dalam rancangan tes adaptif adalah metode Informasi Maksimum. Melalui metode ini, butir soal yang memiliki informasi maksimum pada tingkat kemampuan tertentu akan dipilih dan diberikan kepada peserta tes. Namun kelemahan dari metode ini adalah kurang akurat dalam mengestimasi tingkat kemampuan peserta pada awal tes dan memiliki kecenderungan untuk memilih butir dengan nilai daya pembeda parameter butir yang tinggi dibandingkan butir dengan nilai parameter daya pembeda yang rendah, sehingga menimbulkan masalah pemeliharaan butir soal dalam bank soal. Karena itu dicari cara lain untuk mengatasi masalah tersebut. Penelitian ini bertujuan untuk mengetahui performa hasil estimasi dari penerapan metode Efficiency Balanced Information (EBI) pada rancangan tes adaptif. Penelitian ini dilakukan melalui studi simulasi dalam setting penyelenggaraan ujian akhir semester Universitas Terbuka. Bank soal untuk keperluan simulasi dibangkitkan berdasarkan model Item Response Theory 3 parameter. Sebanyak 900 butir soal dalam bank soal bangkitan dengan spesifikasi parameter butir yang ideal. Dua kriteria pemilihan butir soal yang disimulasikan yaitu Informasi Maksimum dan EBI Maksimum yang juga dirancang agar memenuhi keseimbangan isi. Hal ini agar menjamin bahwa algoritma yang dihasilkan sesuai dengan pembelajaran moduler yang diterapkan UT, artinya butir soal setiap modul secara proporsional terwakili dan sesuai kisi-kisi. Aturan pemberhentian tes menggunakan kesalahan baku estimasi (standard error of estimation=SEE) sebesar 0,3. Hasil penelitian menyimpulkan bahwa algoritma rancangan tes adaptif dengan kriteria EBI menghasilkan performa hasil estimasi kemampuan peserta yang lebih akurat dibandingkan kriteria Informasi Maksimum. Hal ini ditunjukkan oleh nilai bias dan simpangan baku pengukuran yang lebih kecil dibandingkan kriteria Informasi Maksimum. Kelebihan lain dari penerapan kriteria EBI Maksimum adalah kebermanfaatan bank soal lebih optimal karena butir-butir soal dengan tingkat daya beda rendah juga dimunculkan khususnya pada awal tes. Sedangkan kriteria Informasi Maksimum walaupun lebih efisien dari sisi panjang tes tetapi kurang optimal dalam memanfaatkan bank soal.

Exploring the Full-Information Bifactor Model in Vertical Scaling With Construct Shift

To address the lack of attention to construct shift in item response theory (IRT) vertical scaling, a multigroup, bifactor model was proposed to model the common dimension for all grades and the grade-specific dimensions. Bifactor model estimation accuracy was evaluated through a simulation study with manipulated factors of percentage of common items, sample size, and degree of construct shift. In addition, the unidimensional IRT (UIRT) model, which ignores construct shift, was also estimated to represent current practice. It was found that (a) bifactor models were well recovered overall, though the grade-specific dimensions were not as well recovered as the general dimension; (b) item discrimination parameter estimates were overestimated in UIRT models due to the effect of construct shift; (c) the person parameters of UIRT models were less accurately estimated than those of bifactor models; (d) group mean parameter estimates from UIRT models were less accurate than those of bifactor models; and (e) a large effect due to construct shift was found for the group mean parameter estimates of UIRT models. A real data analysis provided an illustration of how bifactor models can be applied to problems involving vertical scaling with construct shift. General procedures for testing practice were recommended and discussed.