The Concept of Good Classification (Diagnostic) Test

Author(s):  
Xenia Naidenova

In this chapter, the definition of good diagnostic test and the characterization of good tests are introduced and the concepts of good maximally redundant and good irredundant tests are given. The algorithms for inferring all kinds of good diagnostic tests are described in detail.

2013 ◽  
Vol 16 (1) ◽  
pp. 281-306 ◽  
Author(s):  
Kusaeri Kusaeri

Penelitian ini bertujuan 1) menemukan cara me-ngembangkan tes diagnostik dengan model DINA, sehingga mampu memberikan informasi salah konsepsi dalam aljabar, 2) mengidentifikasi karakteristik tes diagnostik yang baik yang dikembangkan dengan model DINA. Penelitian pengembangan ini merupakan penelitian empirik, dengan pendekatan deskriptif eksploratori. Pendekatan tersebut digunakan untuk mendeskrip-sikan tahapan pengembangan tes dan mencari karakteristik item. Subjek penelitian adalah siswa kelas VIII SMPN 1 Yogyakarta, SMPN 1 Sanden Bantul dan SMPN 1 Panjatan Kulon Progo. Data dianalisis dengan software CDM, Mplus dan R. Hasil penelitian menunjukan 1) tahapan pengembangan tes meliputi: identifikasi kompetensi dasar dan merumuskan indi-kator, menyusun learning continuum, menyusun hierarki materi, merumuskan atribut, mengonstruk soal, validasi ahli dan uji empirik. Setelah melalui tujuh tahapan, dikembangkan 37 item tes diagnostik, 2) dari 37 item tes diagnostik, 15 item di antaranya harus dihilangkan/dihapus dari paket tes,  karena tidak memenuhi uji fit model dan kualitas item tersebut jelek (indeks daya beda kurang dari 0,2).Kata kunci: DINA, latent class, atribut, salah konsepsi, dan aljabar _____________________________________________________________ DINA IN DEVELOPMENT MODEL USING DIAGNOSTIC TESTS FOR DETECTING WRONG CONCEPTIONAbstract This research aims to 1) find out a way to develop the diagnostic test  using the DINA model, so that it can give information about misconceptions in algebra, 2) Identify the characteristics of the good diagnostic test developed by using the DINA model. This research and development  is an empirical research with the descriptive explanatory used to describe the development stages of the test. The subjects of this research were year VIII students of SMPN 1 Yogyakarta, SMPN 1 Sanden Bantul, and SMPN 1 Panjatan, Kulon Progo. The data were analyzed by using the CDM, Mplus, and R software. The results of the study are as follows 1) The stages of the test development in this research were: identifying basic competence and formulating indicators, constructing the learning continuum, constructing the material hierarchy, formulating the attributes, constructing the problems, conducting validation by expert judgment, and administering an empirical test. Through those seven stages, 37 items of the diagnostic test were developed, 2) Of the 37 items, 15 items must be eliminated/discarded from the test. The items were eliminated because their quality was low and they did not meet the requirements of the model fit test because their discrimination indexes were less than 0.2.Keywords: DINA, latent class, attribute, misconceptions, and algebra


2019 ◽  
Vol 19 (14) ◽  
pp. 1263-1274 ◽  
Author(s):  
Anuradha Kalani ◽  
Komal Kalani ◽  
Poonam Chaturvedi ◽  
Pankaj Chaturvedi

Background:Filariasis affects millions of people in tropical and subtropical regions of the world and is caused by nematode roundworm. In order to develop a vaccine and specific diagnostic tests, it is important to characterize different stages of the filarial worms. Microfilariae (Mf) stage of the roundworm is found in host’s blood or lymph vessels and can be important not only for developing better immunodiagnostics but also for understanding immune recognition and its relevance to immunepathogenesis and protective immunity.Objective:The present study aimed to immunocharacterize Mf and adult worm antigens that could be helpful in future diagnostic tests.Method:Four different immune sera against Setaria cervi intact live, intact live with adjuvant, intact glutaraldehyde fixed with adjuvant and total somatic Mf were prepared and used for the immunocharacterization of Mf antigens.Results:Our study results suggest that compared to fixed intact Mf, live intact Mf are more immunogenic, as the immune sera generated against intact live Mf showed high ELISA reactivity with Setaria cervi Mf and adult worm antigens. All the four immune sera IgG fractions had surface specificity as determined through considerable ELISA reactivity with S. cervi intact Mf. When tested under native conditions (immunoelectrophoresis and crossed immunoelectrophoresis), all the four immune rabbit sera were able to detect antigens of S. cervi Mf and adult stages.Conclusion:These results can be useful in detailed understanding of the complex nature of the Mf and adult antigens, which are prerequisites in the development of vaccine and more specific diagnostic tests.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2313
Author(s):  
Maria Luisa Beconcini ◽  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi ◽  
Benedetta Puccini

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.


2021 ◽  
pp. 1-10
Author(s):  
Narjes Firouzkouhi ◽  
Abbas Amini ◽  
Chun Cheng ◽  
Mehdi Soleymani ◽  
Bijan Davvaz

Inspired by fuzzy hyperalgebras and fuzzy polynomial function (term function), some homomorphism properties of fundamental relation on fuzzy hyperalgebras are conveyed. The obtained relations of fuzzy hyperalgebra are utilized for certain applications, i.e., biological phenomena and genetics along with some elucidatory examples presenting various aspects of fuzzy hyperalgebras. Then, by considering the definition of identities (weak and strong) as a class of fuzzy polynomial function, the smallest equivalence relation (fundamental relation) is obtained which is an important tool for fuzzy hyperalgebraic systems. Through the characterization of these equivalence relations of a fuzzy hyperalgebra, we assign the smallest equivalence relation α i 1 i 2 ∗ on a fuzzy hyperalgebra via identities where the factor hyperalgebra is a universal algebra. We extend and improve the identities on fuzzy hyperalgebras and characterize the smallest equivalence relation α J ∗ on the set of strong identities.


2021 ◽  
Vol 22 (9) ◽  
pp. 4707
Author(s):  
Mariana Lopes ◽  
Sandra Louzada ◽  
Margarida Gama-Carvalho ◽  
Raquel Chaves

(Peri)centromeric repetitive sequences and, more specifically, satellite DNA (satDNA) sequences, constitute a major human genomic component. SatDNA sequences can vary on a large number of features, including nucleotide composition, complexity, and abundance. Several satDNA families have been identified and characterized in the human genome through time, albeit at different speeds. Human satDNA families present a high degree of sub-variability, leading to the definition of various subfamilies with different organization and clustered localization. Evolution of satDNA analysis has enabled the progressive characterization of satDNA features. Despite recent advances in the sequencing of centromeric arrays, comprehensive genomic studies to assess their variability are still required to provide accurate and proportional representation of satDNA (peri)centromeric/acrocentric short arm sequences. Approaches combining multiple techniques have been successfully applied and seem to be the path to follow for generating integrated knowledge in the promising field of human satDNA biology.


Author(s):  
M. Ferrara ◽  
M. Trombetti

AbstractLet G be an abelian group. The aim of this short paper is to describe a way to identify pure subgroups H of G by looking only at how the subgroup lattice $$\mathcal {L}(H)$$ L ( H ) embeds in $$\mathcal {L}(G)$$ L ( G ) . It is worth noticing that all results are carried out in a local nilpotent context for a general definition of purity.


2012 ◽  
Vol 730-732 ◽  
pp. 569-574
Author(s):  
Marta Cabral ◽  
Fernanda Margarido ◽  
Carlos A. Nogueira

Spent Ni-MH batteries are not considered too dangerous for the environment, but they have a considerable economical value due to the chemical composition of electrodes which are highly concentrated in metals. The present work aimed at the physical and chemical characterisation of spent cylindrical and thin prismatic Ni-MH batteries, contributing for a better definition of the recycling process of these spent products. The electrode materials correspond to more than 50% of the batteries weight and contain essentially nickel and rare earths (RE), and other secondary elements (Co, Mn, Al). The remaining components are the steel parts from the external case and supporting grids (near 30%) containing Fe and Ni, and the plastic components (<10%). Elemental quantitative analysis showed that the electrodes are highly concentrated in metals. Phase identification by X-ray powder diffraction combined with chemical analysis and leaching experiments allowed advancing the electrode materials composition. The cathode is essentially constituted by 6% metallic Ni, 66% Ni(OH)2, 4.3% Co(OH)2 and the anode consists mainly in 62% RENi5 and 17% of substitutes and/or additives such as Co, Mn and Al.


2021 ◽  
Vol 13 (6) ◽  
pp. 3272
Author(s):  
Paúl Carrión-Mero ◽  
Maribel Aguilar-Aguilar ◽  
Fernando Morante-Carballo ◽  
María José Domínguez-Cuesta ◽  
Cristhian Sánchez-Padilla ◽  
...  

In the last decade, in the mining district of Zaruma-Portovelo, there has been significant land subsidence related to uncontrolled mining activity. The purpose of this work was to carry out a surface and underground geomechanical characterization of a mining sector north of the city of Zaruma that allows the definition of potentially unstable areas susceptible to the mass movement. The methodology used consists of the following stages: (i) compilation of previous studies; (ii) surface and underground characterization of rocky material to establish its susceptibility to mass movement; (iii) interpretation of results; and (iv) proposal of action measures. Among the most relevant results, it stands out that 26.1% of the 23 stations characterized on the surface present conditions that vary from potentially unstable to unstable. In underground galleries, the studied mean values of the 17 stations indicate that the rock has a medium to good quality, representing a medium susceptibility to gallery destabilization. The results obtained for the surface areas (depths up to 50 m, where altered materials predominate) and the underground areas (depths > 50 m, where the alterations are specific) can be used to identify the areas with a more significant potential for instability. For both cases, it has been possible to define specific monitoring, control, and planning actions for sensitive areas.


1989 ◽  
Vol 12 (2) ◽  
pp. 263-266
Author(s):  
Prabir Bhattacharya ◽  
N. P. Mukherjee

For a finite group G and an arbitrary prime p, letSP(G)denote the intersection of all maximal subgroups M of G such that [G:M] is both composite and not divisible by p; if no such M exists we setSP(G)= G. Some properties of G are considered involvingSP(G). In particular, we obtain a characterization of G when each M in the definition ofSP(G)is nilpotent.


Sign in / Sign up

Export Citation Format

Share Document