Cheating is a common phenomenon in high stakes admission, licensing and university exams and threatens their validity. To detect if some exam questions had been affected by cheating, we simulated how data would look like if some test takers possessed item preknowledge: Responses to a small number of items were set to correct for 1-10% of test takers. Item difficulty, item discrimination, item f...

We apply collaborative filtering (CF) to dichotomously scored student response data (right, wrong, or no interaction), finding optimal parameters for each student and item based on cross-validated prediction accuracy. The approach is naturally suited to comparing different models, both unidimensional and multidimensional in ability, including a widely used subset of Item Response Theory (IRT) m...

This paper presents description of real time database system. Like conventional database, real time data-base system must handle transactions with timing constraint. Real-time database systems must maintain both logical and temporal data integrity so that transactions can respond to real-world events timely and predictably. This paper, first presents concurrency control mechanism including vari...

We investigate the performance of three statistics, R1, R2 (Glas in Psychometrika 53:525-546, 1988), and M2 (Maydeu-Olivares & Joe in J. Am. Stat. Assoc. 100:1009-1020, 2005, Psychometrika 71:713-732, 2006) to assess the overall fit of a one-parameter logistic model (1PL) estimated by (marginal) maximum likelihood (ML). R1 and R2 were specifically designed to target specific assumptions of Rasc...

BACKGROUND Patient-generated health outcome measures are important in the assessment of long-term treatment goals for Rheumatoid Arthritis (RA), but few psychometrically sound measures are available. The MAPLe-RA (Measuring Actual Patient-Led expectations in RA) is a new questionnaire and its psychometric properties are not investigated. This study aims to examine these properties for each of t...

Given an undirected graph with nonnegative edge costs and an integer k, the k-MST problem is that of finding a tree of minimum cost on k nodes. This problem is known to be NP-hard. We present a simple approximation algorithm that finds a solution whose cost is less than 17 times the cost of the optimum. This improves upon previous performance ratios for this problem &O(k) due to Ravi et al., O(...

Introduction Given the profound changes caused in higher education by COVID-19 pandemic, affecting 1.6 billion students and 63 million educators globally, there arises necessity for quantifiable measures that capture essence of academic co-creation. This study aimed to develop validate a short scale co-creation (AC-S) sample students. Methods A total 3,169 from three Peruvian cities participate...

This paper introduces, as an optimistic concurrency control, a new certification method by means of intervals of timestamps, usable in a distributed database system. The main advantage of this method is that it allows a chronological validation order which differs from the serialization one (thus avoiding rejections or delays of transactions which occur in usual certification methods or in clas...

Item response theory is a large sample procedure to estimate item parameters based on individual response strings. However, what happens when the data available to estimate item parameters is small? This situation is common when new assessment items are tried out for inclusion in future operational assessments, commonly called field testing. In field tests, many items are spread out over a fixe...

The aim of the study was to evaluate a novel diagnostic scheme which combines quantitative PCR and High-Resolution Melting (qPCR-HRM) curve analysis for rapid differentiation based on E5 partial CDS of bovine papillomavirus type 1 or 2 (BPV-1 or BPV-2), and to perform a phylogenetic analysis of the complete CDS of the E5 gene of BPV detected in equine sarcoids. Samples of 38 skin lesions obtain...