scholarly journals Improved Quality: Item and Test parameters

2021 ◽  
Vol 2020 ◽  
Author(s):  
Satyendra Nath Chakrabartty

Introduction:  Quality of a MCQ type test depends on qualities of the constituent items, assessed in terms of item reliability, item difficulty value, item discriminating value, etc. However, quality of a test involving reliability, validity, difficulty and discriminating values of the test etc. requires new approaches. Need is felt to find difficulty and discriminating values of an item and test using entire data and  to derive relationships amongst them including relationship with test reliability to see impact of item deletion. Methods: Using angular similarity approach, measures proposed for item difficulty and item discriminating value, difficulty and discriminating value of test. Relationship derived between (i) difficulty value and discriminating value of item; (ii) difficulty value and discriminating value of a test (iii) test discriminating value and test reliability as per theoretical definition. Cronbach alpha was expressed using sum of item difficulty values and test discriminating value Results and Discussion: Each proposed measure ranges between 0 to 1. Discriminating value of test and item as coefficient of variation satisfy desired properties and facilitates population estimations. Intersection of item difficulty and item discriminating curves provides a data driven criterion for item deletion, impact of which on test reliability may be checked.  In addition, the proposed measures facilitate testing of statistical hypothesis of departure of test reliability from unity, confidence interval of reliability, etc. Future problems suggested.

Author(s):  
Satyendra Nath CHAKRABARTTY

The paper proposes new measures of difficulty and discriminating values of binary items and test consisting of such items and find their relationships including estimation of test error variance and thereby the test reliability, as per definition using cosine similarities. The measures use entire data. Difficulty value of test and item is defined as function of cosine of the angle between the observed score vector and the maximum possible score vector. Discriminating value of test and an item are taken as coefficient of variation (CV) of test score and item score respectively. Each ranges between 0 and 1 like difficulty value of test and an item. With increase in number of correct answer to an item, item difficulty curve increases and item discriminating curve decreases. The point of intersection of the two curves can be used for item deletion along with other criteria. Cronbach alpha was expressed and computed in terms of discriminating value of test and item. Relationship derived between test discriminating value and test reliability as per theoretical definition. Empirical verifications of proposed measures were undertaken. Future studies suggested.re to enter text.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Rizki Nor Amelia ◽  
Anggi Ristiyana Puspita Sari ◽  
Sri Rejeki Dwi Astuti

The teacher-made chemistry test must have a good quality, due to the decision taken from the tests has an impact on the students. Therefore, the purpose of the research is to explore the quality of teacher-made chemistry tests such as item fit and person fit, items difficulty, and test reliability. The sample consisted of 356 senior students from senior high schools in Yogyakarta that were selected by cluster random sampling technique. The research used the teacher-made chemistry test consisted of 40 multiple choice items which were collected using documentation technique. Data were analyzed with Rasch Model using Winsteps 3.73 version. The result showed that all items in the teacher-made chemical test were proven to have good quality (fit model, good item difficulty, and good test reliability). Moreover, 18 students were identified as misfit persons. From the findings, the test can be used to assess the students’ learning outcomes, especially for the try-out of the final exam in senior high school. Besides, the students identified as person misfit should be further examined and receive teachers’ guidance.


2021 ◽  
Vol 14 (1) ◽  
pp. 205979912098778
Author(s):  
Satyendra Nath Chakrabartty

Through N-dimensional person space, the article gives measures of test parameters and item statistics, including difficulty/discriminating value of test, correlations between a pair of items, and item-total correlations with binary items using angular similarity between two vectors. Relationships between difficulty value and discriminating value of items and test were derived, including relationship between test reliability and test discriminating value. Reliability of a test as per theoretical definition in terms of length of score vectors of two parallel subtests and angle between such vectors was derived. The method was extended to find reliability of a battery of tests. Reliability and discriminating value of a Likert-type item and scale was found in terms of angular similarity without involving assumptions of continuous nature or linearity or normality for the observed variables, or the underlying variable being measured. The proposed methods also avoid test of unidimensionality or assumption of normality or bivariate normality associated with the polychoric correlations. Thus, the proposed methods are in fact nonparametric and considered as improvement over the existing ones. Reliability as a measure of association of two vectors and discrimination as a measure of distance between the vectors are likely to show a negative relationship.


2021 ◽  
Vol 11 (11) ◽  
pp. 5294
Author(s):  
Peer Decker ◽  
Ines Zerbin ◽  
Luisa Marzoli ◽  
Marcel Rosefort

Two different intergranular corrosion tests were performed on EN AW-6016 sheet material, an ISO 11846:1995-based test with varying solution amounts and acid concentrations, and a standard test of an automotive company (PV1113, VW-Audi). The average intergranular corrosion depth was determined via optical microscopy. The differences in the intergranular corrosion depths were then discussed with regard to the applicability and quality of the two different test methods. The influence of varying test parameters for ISO 11846:1995 was discussed as well. The determined IGC depths were found to be strongly dependent on the testing parameters, which will therefore have a pronounced influence on the determined IGC susceptibility of a material. In general, ISO 11846:1995 tests resulted in a significantly lower corrosion speed, and the corrosive attack was found to be primarily along grain boundaries.


2020 ◽  
Vol 32 (S1) ◽  
pp. 180-180
Author(s):  
Philippe Landreville ◽  
Alexandra Champagne ◽  
Patrick Gosselin

Background.The Geriatric Anxiety Inventory (GAI) is a widely used self-report measure of anxiety symptoms in older adults. Much research has been conducted on the psychometric properties of the GAI in various populations and using different language versions. Previous reviews of this literature have examined only a small proportion of studies in light of the body of research currently available and have not evaluated the methodological quality of this research. We conducted a systematic review of the psychometric properties of the GAI.Method.Relevant studies (N = 30) were retrieved through a search of electronic databases (Pubmed, PsycINFO, CINAHL, EMBASE and Google Scholar) and a hand search. The methodological quality of the included studies was assessed by two independent reviewers using the ‘‘COnsensusbased Standards for the selection of health status Measurement INstruments’’ (COSMIN) checklist.Results.Based on the COSMIN checklist, internal consistency and test reliability were mostly rated as poorly assessed (62.1% and 70% of studies, respectively) and quality of studies examining structural validity was mostly fair (60% of studies). The GAI showed adequate internal consistency and test-retest reliability. Convergent validity indices were highest with measures of generalized anxiety and lowest with instruments that include somatic symptoms. A substantial overlap with measures of depression was reported. While there was no consensus on the factorial structure of the GAI, several studies found it to be unidimensional.Conclusions.The GAI presents satisfactory psychometric properties. However, future efforts should aim to achieve a higher degree of methodological quality.


Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 318
Author(s):  
Merima Kulin ◽  
Tarik Kazaz ◽  
Eli De Poorter ◽  
Ingrid Moerman

This paper presents a systematic and comprehensive survey that reviews the latest research efforts focused on machine learning (ML) based performance improvement of wireless networks, while considering all layers of the protocol stack: PHY, MAC and network. First, the related work and paper contributions are discussed, followed by providing the necessary background on data-driven approaches and machine learning to help non-machine learning experts understand all discussed techniques. Then, a comprehensive review is presented on works employing ML-based approaches to optimize the wireless communication parameters settings to achieve improved network quality-of-service (QoS) and quality-of-experience (QoE). We first categorize these works into: radio analysis, MAC analysis and network prediction approaches, followed by subcategories within each. Finally, open challenges and broader perspectives are discussed.


2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Matthieu J. S. Brinkhuis ◽  
Alexander O. Savi ◽  
Abe D. Hofman ◽  
Frederik Coomans ◽  
Han L. J. Van der Maas ◽  
...  

With the advent of computers in education, and the ample availability of online learning and practice environments, enormous amounts of data on learning become available. The purpose of this paper is to present a decade of experience with analyzing and improving an online practice environment for math, which has thus far recorded over a billion responses. We present the methods we use to both steer and analyze this system in real-time, using scoring rules on accuracy and response times, a tailored rating system to provide both learners and items with current ability and difficulty ratings, and an adaptive engine that matches learners to items. Moreover, we explore the quality of fit by means of prediction accuracy and parallel item reliability. Limitations and pitfalls are discussed by diagnosing sources of misfit, like violations of unidimensionality and unforeseen dynamics. Finally, directions for development are discussed, including embedded learning analytics and a focus on online experimentation to evaluate both the system itself and the users’ learning gains. Though many challenges remain open, we believe that large steps have been made in providing methods to efficiently manage and research educational big data from a massive online learning system.


2021 ◽  
pp. 9-10
Author(s):  
Bhoomika R. Chauhan ◽  
Jayesh Vaza ◽  
Girish R. Chauhan ◽  
Pradip R. Chauhan

Multiple choice questions are nowadays used in competitive examination and formative assessment to assess the student's eligibility and certification.Item analysis is the process of collecting,summarizing and using information from students' responses to assess the quality of test items.Goal of the study was to identify the relationship between the item difficulty index and item discriminating index in medical student's assessment. 400 final year medical students from various medical colleges responded 200 items constructed for the study.The responses were assessed and analysed for item difficulty index and item discriminating power. Item difficulty index an item discriminating power were analysed by statical methods to identify correlation.The discriminating power of the items with difficulty index in 40%-50% was the highest. Summary and Conclusion:Items with good difficulty index in range of 30%-70% are good discriminator.


2017 ◽  
Vol 4 (02) ◽  
pp. 274-293
Author(s):  
Nur Hidayati ◽  
J.M.V. Mulyadi

ABSTRACT The purpose of this study is to examine whether variables such as quality of goods/services procurement committee, income of goods/services procurement committee, procurement system and procurement system, procurement ethic of goods/services and internal control system have influence to fraud of goods/ services procurement in the ministry of health affairs agency. Population in this research is all auditor related in process of procurement of goods/services, while the object of research (sample) that is as much as 56 people. The technique of determining the sample using purposive sampling method. Data were tested using validity test, reliability test, multicolinearity test, heteroskedasticity test, multiple regression analysis, hypothesis test and coefficient of determination. The result of the research shows that the quality of procurement committee variables significantly and negatively affect the fraud of procurement of goods/services. The income of the procurement committee does not significantly affect the procurement of goods/services, procurement system and procedures have significant effect and negative to the goods/service procurement, ethics have significant effect and negative to the procurement of goods/services and internal control system significantly and negative to the fraud of procurement of goods/services. ABSTRAK Tujuan dari penelitian ini adalah untuk menguji apakah variabel seperti kualitas panitia pengadaan barang/jasa, penghasilan panitia pengadaan barang/jasa, sistem dan prosedur pengadaan barang/jasa, etika pengadaan barang/jasa, dan sistem pengendalian internal memiliki pengaruh terhadap fraud pengadaan barang/jasa di Lingkungan Instansi Kementerian Kesehatan RI. Populasi dalam penelitian ini adalah seluruh auditor yang terkait dalam proses pengadaan barang/jasa, sedangkan yang dijadikan objek penelitian (sampel) yaitu sebanyak 56 orang. Teknik penentuan sampel menggunakan metode purposive sampling. Data diuji menggunakan uji validitas, uji reliabilitas, uji multikolinearitas, uji heteroskedastisitas, analisis regresi berganda, uji hipotesis dan koefisien determinasi. Hasil penelitian menunjukkan bahwa variabel kualitas panitia pengadaan berpengaruh secara signifikan dan negatif terhadap fraud pengadaan barang/jasa. Penghasilan panitia pengadaan tidak berpengaruh secara signifikan terhadap terhadap fraud pengadaan barang/jasa, sistem dan prosedur pengadaan berpengaruh secara signifikan dan negatif terhadap fraud pengadaan barang/jasa, ketika berpengaruh secara signifikan dan negatif terhadap fraud pengadaan barang/jasa dan sistem pengendalian internal berpengaruh secara signifikan dan negatif terhadap fraud pengadaan barang/jasa. JEL Classification: M41, M42, H57


2021 ◽  
Vol 15 (2) ◽  
pp. 234-241
Author(s):  
Efi Septianingsih ◽  
Mohammad Adam Jerusalem

The paper aims to develop the instrument about analogy test to measure the level of intelligence of undergraduate students. Determination of the number of samples is done by purposive sampling technique. This instrument is analyzed by factor analysis. Of the 15 items that will be used to develop the academic potential test instrument for verbal analogies, 4 analysis factors. The formation of these 4 factors is from Eigenvalues greater than 1 so that there are only 4 factors that fulfill the requirements. Furthermore, 15 items of the tested instrument to 91 undergraduate student respondents obtained 2 items of invalid instrument with correlation coefficient ≤0.3, Kaiser-Meyer-Olkin (KMO) and Bartlett's test amounted to 0.785 with p 0.05. Trial results from the results of the trial results obtained that the average validity of the questions is 96.8%. Test reliability was analyzed using the Alpha (α) formula of Cronbach. The calculation is done using the help of the IBM SPSS version 22.0 Windows program and the coefficient of 0.806 is obtained. Based on the results of the research, it can be concluded that the quality of the developed instrument items has been valid and reliable.


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