scholarly journals Identifying Informatively Easy and Informatively Hard Concepts

2022 ◽  
Vol 22 (1) ◽  
pp. 1-28
Author(s):  
R. Paul Wiegand ◽  
Anthony Bucci ◽  
Amruth N. Kumar ◽  
Jennifer Albert ◽  
Alessio Gaspar

In this article, we leverage ideas from the theory of coevolutionary computation to analyze interactions of students with problems. We introduce the idea of informatively easy or hard concepts. Our approach is different from more traditional analyses of problem difficulty such as item analysis in the sense that we consider Pareto dominance relationships within the multidimensional structure of student–problem performance data rather than average performance measures. This method allows us to uncover not just the problems on which students are struggling but also the variety of difficulties different students face. Our approach is to apply methods from the Dimension Extraction Coevolutionary Algorithm to analyze problem-solving logs of students generated when they use an online software tutoring suite for introductory computer programming called problets . The results of our analysis not only have implications for how to scale up and improve adaptive tutoring software but also have the promise of contributing to the identification of common misconceptions held by students and thus, eventually, to the construction of a concept inventory for introductory programming.

2017 ◽  
Vol 5 (2) ◽  
pp. 162-176
Author(s):  
Ismail Saglam

Baron and Myerson (BM; 1982, Econometrica, 50(4), 911–930) propose an incentive-compatible, individually rational and ex ante socially optimal direct-revelation mechanism to regulate a monopolistic firm with unknown costs. Their mechanism is not ex post Pareto dominated by any other feasible direct-revelation mechanism. However, there also exist an uncountable number of feasible direct-revelation mechanisms that are not ex post Pareto dominated by the BM mechanism. To investigate whether the BM mechanism remains in the set of ex post undominated mechanisms when the Pareto axiom is slightly weakened, we introduce the ∈-Pareto dominance. This concept requires the relevant dominance relationships to hold in the support of the regulator’s beliefs everywhere except for a set of points of measure ∈, which can be arbitrarily small. We show that a modification of the BM mechanism which always equates the price to the marginal cost can ∈-Pareto dominate the BM mechanism at uncountably many regulatory environments, while it is never ∈-Pareto dominated by the BM mechanism at any regulatory environment.


Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2837
Author(s):  
Saykat Dutta ◽  
Sri Srinivasa Raju M ◽  
Rammohan Mallipeddi ◽  
Kedar Nath Das ◽  
Dong-Gyu Lee

In multi/many-objective evolutionary algorithms (MOEAs), to alleviate the degraded convergence pressure of Pareto dominance with the increase in the number of objectives, numerous modified dominance relationships were proposed. Recently, the strengthened dominance relation (SDR) has been proposed, where the dominance area of a solution is determined by convergence degree and niche size (θ¯). Later, in controlled SDR (CSDR), θ¯ and an additional parameter (k) associated with the convergence degree are dynamically adjusted depending on the iteration count. Depending on the problem characteristics and the distribution of the current population, different situations require different values of k, rendering the linear reduction of k based on the generation count ineffective. This is because a particular value of k is expected to bias the dominance relationship towards a particular region on the Pareto front (PF). In addition, due to the same reason, using SDR or CSDR in the environmental selection cannot preserve the diversity of solutions required to cover the entire PF. Therefore, we propose an MOEA, referred to as NSGA-III*, where (1) a modified SDR (MSDR)-based mating selection with an adaptive ensemble of parameter k would prioritize parents from specific sections of the PF depending on k, and (2) the traditional weight vector and non-dominated sorting-based environmental selection of NSGA-III would protect the solutions corresponding to the entire PF. The performance of NSGA-III* is favourably compared with state-of-the-art MOEAs on DTLZ and WFG test suites with up to 10 objectives.


2017 ◽  
Vol 16 (2) ◽  
pp. ar35 ◽  
Author(s):  
Jenny L. McFarland ◽  
Rebecca M. Price ◽  
Mary Pat Wenderoth ◽  
Patrícia Martinková ◽  
William Cliff ◽  
...  

We present the Homeostasis Concept Inventory (HCI), a 20-item multiple-choice instrument that assesses how well undergraduates understand this critical physiological concept. We used an iterative process to develop a set of questions based on elements in the Homeostasis Concept Framework. This process involved faculty experts and undergraduate students from associate’s colleges, primarily undergraduate institutions, regional and research-intensive universities, and professional schools. Statistical results provided strong evidence for the validity and reliability of the HCI. We found that graduate students performed better than undergraduates, biology majors performed better than nonmajors, and students performed better after receiving instruction about homeostasis. We used differential item analysis to assess whether students from different genders, races/ethnicities, and English language status performed differently on individual items of the HCI. We found no evidence of differential item functioning, suggesting that the items do not incorporate cultural or gender biases that would impact students’ performance on the test. Instructors can use the HCI to guide their teaching and student learning of homeostasis, a core concept of physiology.


2020 ◽  
Vol 16 (2) ◽  
pp. 138-148
Author(s):  
Tiina Kiviniemi ◽  
Piia Nuora

A chemistry concept inventory (Chemical Concept Inventory 3.0/CCI 3.0), previously developed for use in Norwegian universities, was tested and evaluated for use in a Finnish university setting. The test, designed to evaluate student knowledge and learning of chemistry concepts, was administered as both pre- and posttest in first year general chemistry courses at the University of Jyväskylä. The results were evaluated using different statistical tests, focusing both on individual item analysis and the entire test. Some individual questions were found to be not discriminating or reliable enough or too difficult, yet the results, as a whole, indicate that the concept inventory is a reliable and discriminating tool that can be used in the Finnish university context.


2016 ◽  
Vol 15 (2) ◽  
pp. ar24 ◽  
Author(s):  
Katherine M. Stefanski ◽  
Grant E. Gardner ◽  
Rebecca L. Seipelt-Thiemann

Concept inventories (CIs) are valuable tools for educators that assess student achievement and identify misconceptions held by students. Results of student responses can be used to adjust or develop new instructional methods for a given topic. The regulation of gene expression in both prokaryotes and eukaryotes is an important concept in genetics and one that is particularly challenging for undergraduate students. As part of a larger study examining instructional methods related to gene regulation, the authors developed a 12-item CI assessing student knowledge of the lac operon. Using an established protocol, the authors wrote open-ended questions and conducted in-class testing with undergraduate microbiology and genetics students to discover common errors made by students about the lac operon and to determine aspects of item validity. Using these results, we constructed a 12-item multiple-choice lac operon CI called the Lac Operon Concept Inventory (LOCI), The LOCI was reviewed by two experts in the field for content validity. The LOCI underwent item analysis and was assessed for reliability with a sample of undergraduate genetics students (n = 115). The data obtained were found to be valid and reliable (coefficient alpha = 0.994) with adequate discriminatory power and item difficulty.


Author(s):  
Per-Odd Eggen ◽  
Jonas Persson ◽  
Elisabeth Egholm Jacobsen ◽  
Bjørn Hafskjold

A Chemistry concept inventory has been developed for assessing students learning and identifying the alternative conceptions that students may have in general chemistry. The conceptions in question are assumed to be mainly learned in school and to a less degree in student’s daily life. The inventory therefore aims at functioning as a tool for adjusting teaching practices in chemistry. The concept inventory presented here is mainly aimed at assessing students learning during general chemistry courses. The inventory has been administered and evaluated using statistical tests, focusing on both item analysis and on the entire test. The results indicate that the concept inventory is a reliable and discriminating tool in the present context.


Author(s):  
Cui Wang ◽  
Zhiwei Ma ◽  
Juliana Y. Leung ◽  
Stefan D. Zanon

Application of big data analytics in reservoir engineering has gained wide attention in recent years. However, designing practical data-driven models for correlating petrophysical measurements and Steam-Assisted Gravity Drainage (SAGD) production profiles using actual field data remains difficult. Parameterization of the complex reservoir heterogeneities in these reservoirs is not trivial. In this study, a set of attributes pertinent to characterizing stochastic distributions of shales and lean zones is formulated and used for correlating against a number of production performance measures. A comprehensive investigation of the heterogeneous distribution (continuity, size, proportions, permeability, location, orientation and saturation) of shale barriers and lean zones is presented. First, a series of two-dimensional SAGD models based on typical Athabasca oil reservoir properties and operating conditions are constructed. Geostatistical techniques are applied to stochastically model shale barriers, which are imbedded in a region of degraded rock properties referred to as Low-Quality Sand or LQS, among a background of clean sand. Parameters including correlation lengths, orientation, proportions and permeability anisotropy of the different rock facies are varied. Within each facies, spatial variations in water saturation are modeled probabilistically. In contrast to many previous simulation studies, representative multiphase flow functions and capillarity models are assigned in accordance to individual facies. A set of input attributes based on facies proportions and dimensionless correlation lengths are formulated. Next, to facilitate the assessment of different scenarios, production performance is quantified by numerous dimensionless output attributes defined from recovery factor and steam-to-oil ratio profiles. An additional dimensionless indicator is implemented to capture the production time during which the instantaneous steam-to-oil ratio has exceeded a particular economic threshold. Finally, results of the sensitivity analysis are employed as training and testing datasets in a series of neural network models to correlate the pertinent system attributes and the production performance measures. These models are also used to assess the consequences of ignoring lateral variation of heterogeneities when extracting petrophysical (log) data from vertical delineation wells alone. An important contribution of this work is that it proposes a set of input attributes for correlating reservoir heterogeneity introduced by shale barriers and lean zones to SAGD production performance. It demonstrates that these input attributes, which can be extracted from petrophysical logs, are highly correlated with the ensuing recovery response and heat loss. This work also exemplifies the feasibility and utility of data-driven models in correlating SAGD performance. Furthermore, the proposed set of system variables and modeling approach can be applied directly in field-data analysis and scale-up study of experimental models to assist field-operation design and evaluation.


2017 ◽  
Vol 14 (2) ◽  
pp. 2021
Author(s):  
Emrah Oğuzhan Dinçer ◽  
Derya Çobanoğlu Aktan

The aim of this study is to adapt “Star Properties Concept Inventory-SPCI” developed by Bailey, Johnson, Prather, and Slater (2012) into Turkish, and to make validity and reliability analyses of the inventory. The original inventory is consisted of 22 items. The study is conducted with the participation of 386 students from three different universities. Preservice science teachers and fourth grade astronomy students are formed this research group.  Cronbach’s alpha coefficient is determined as 0.82 for the inventory. As a result of item analysis of data gained from application of inventory; item discrimination indexes are found between 0.07 and 0.73, item difficulty indexes are found between 0.13 and 0.75.  While the average of test is found as 7.27, the average difficulty is 0.33. The content validity is determined by taking expert opinions.Extended English abstract is in the end of PDF (TURKISH) file.  ÖzetBu çalışmanın amacı, Bailey, Johnson, Prather ve Slater (2012) tarafından geliştirilen “Star Properties Concept Inventory-SPCI” Yıldız Özellikleri Kavram Envanterini (YÖKE) Türkçeye uyarlamak ve Türkçe uyarlamanın güvenirlik ve geçerlik çalışmasını yapmaktır. Envanterin orijinali 22 sorudan oluşmaktadır. Araştırma üç farklı üniversiteden toplam 386 öğrencinin katılımı ile gerçekleştirilmiştir. Araştırma örneklemi, astronomi bölümü dördüncü sınıf öğrencileri ile fen ve teknoloji öğretmen adaylarından oluşmaktadır.  Cronbach alfa katsayısı ölçme aracı için 0.82 olarak belirlenmiştir. Kavram testinin uygulanması sonucu elde edilen verilerin madde analizi sonucunda maddelerin ayırıcılık güçlerinin 0.07 ile 0.73 arasında, madde güçlük indislerinin de 0.13 ile 0.75 arasında olduğu bulunmuştur. Testin ortalaması 7.27 bulunurken, testin ortalama güçlüğü de 0.33’tür. Testin kapsam geçerliği uzman görüşleri alınarak belirlenmiştir.


2013 ◽  
Vol 12 (4) ◽  
pp. 655-664 ◽  
Author(s):  
Pamela Kalas ◽  
Angie O’Neill ◽  
Carol Pollock ◽  
Gülnur Birol

We have designed, developed, and validated a 17-question Meiosis Concept Inventory (Meiosis CI) to diagnose student misconceptions on meiosis, which is a fundamental concept in genetics. We targeted large introductory biology and genetics courses and used published methodology for question development, which included the validation of questions by student interviews (n = 28), in-class testing of the questions by students (n = 193), and expert (n = 8) consensus on the correct answers. Our item analysis showed that the questions’ difficulty and discrimination indices were in agreement with published recommended standards and discriminated effectively between high- and low-scoring students. We foresee other institutions using the Meiosis CI as both a diagnostic tool and an instrument to assess teaching effectiveness and student progress, and invite instructors to visit http://q4b.biology.ubc.ca for more information.


Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.


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