Newly-developed Model Research Articles

Nitrogen and phosphorus cycling for aquaculture ponds with artificially-controlled drainage: Sources, sinks and treatment strategies

Nitrogen (N) and phosphorus (P) loss from freshwater aquaculture ponds has been an on-going challenge due to its direct link to lake/river eutrophication. However, characterizing N & P cycling and its response to treatment strategies for the ecosystems is difficult due to the complexity of artificially-controlled drainage and biogeochemical cycling. To address this challenge, this study specifically developed a nutrient dynamic model (Pond-NP) for aquaculture ponds to track the daily sources, sinks and biogeochemical cycling of N & P. A month sampling program was carried out at a typical Chinese mitten crab (Eriocheir sinensis) culture pond during 2020–2022 to evaluate the model performance. The model achieved a model fit of Nash-Sutcliffe efficiency >0.43. Our modelling practices revealed that the studied pond had a total inputs of 187.3 kg N/ha/yr and 29.8 kg P/ha/yr, with N & P use efficiencies of 35.4% and 28.1%, respectively. Among the used N & P, macrophytes had a larger (>51.2%) contribution than the cultivated animals, resulting in a limited improvement (<2%) of nutrient use efficiency via the stocking strategies. More input N & P was lost to sediment (31.4% and 63.4% of total inputs) than surrounding rivers (17.6% and 8.5% of total inputs). Ex-situ ecological treatment was estimated to reduce N & P significantly (>40%) for aquaculture tail water, and was thus recommended to control N & P loss together with sediment reuse. This study demonstrated the high value of our newly-developed model in quantifying N & P loss, and thus supporting the design of N & P mitigation strategies for aquaculture ponds.

Integration of energy system and computable general equilibrium models: An approach complementing energy and economic representations for mitigation analysis

Energy system and computable general equilibrium (CGE) models play vital roles in climate change mitigation studies. These models have advantages and disadvantages, and attempts have been made to integrate them. This study aimed to describe the method for integrating energy system and CGE models and demonstrate the new model that captures the strengths of both models. The method developed in this study ensured the detailed convergence of the energy system by exchanging the results iteratively. We demonstrated the model integration by adopting the method to MESSAGEix-GLOBIOM and AIM/Hub and estimating a mitigation scenario that limits the temperature rise to below 2 °C under the middle-of-the-road socioeconomic projection in Shared Socioeconomic Pathways. As a result of the integration, the index showing the difference between the two models proposed in this study decreased from 1.0 to 0.066. Therefore, we confirmed that these models estimated consistent scenarios. The diagnostic indicators showed that compared to its counterpart CGE model, the newly-developed model was characterized by a higher contribution of demand-side reductions, a lesser alteration in the primary energy supply composition, and lower abatement costs. Given the convergence and advantages of the integrated framework, the proposed method is useful for further application to mitigation studies.

Modelling the influence of beach building pole heights on aeolian morphology and downwind sediment transport

Buildings on beaches either sit directly on the sediment surface or are placed on poles. These structures alter near-bed airflow around them. To quantify the influence of pole height on airflow, resulting bed morphology around these buildings and sediment fluxes passing these buildings towards the dunes, three-dimensional simulations were performed. To compute airflow, we used the open-source computational fluid dynamics software OpenFOAM. For sand transport and bed level changes, we used the Exner equation combined with Bagnold's sediment transport flux formulation, and a newly-developed model that couples the airflow model with the sediment transport model AeoLiS. In the simulations, we modelled a row of ten full-scale beach buildings on a flat/smooth sandy bed, with a constant gap size between neighbouring buildings, varying the pole heights between simulations. Our findings showed that elevated buildings affect the wind speed in a larger region, both upwind and downwind, compared to buildings without poles. The model simulations showed that airflow accelerated both underneath the elevated buildings and through the gaps between the buildings. Moreover, besides flow acceleration underneath the buildings, the elevated buildings induced slightly higher flow acceleration through the gaps between buildings. Depending on pole height to building width ratio, elevated buildings could both decrease and increase the downwind sediment flux compared to an undisturbed situation. For ratios between 0 and 0.5, downwind fluxes were reduced in a zone between 5 and 40 m behind the buildings, while for ratios above 1.3, downwind fluxes were observed to increase in a zone up to 20 m behind the buildings. Also, this study emphasizes the importance of selecting an optimal pole height to maximize the benefits of beach buildings in terms of passing on sediment transport towards the dunes.

Extension of the general unit hydrograph theory for the spread of salinity in estuaries

Abstract. From both practical and theoretical perspectives, it is essential to be able to express observed salinity distributions in terms of simplified theoretical models, which enable qualitative assessments to be made in many problems concerning water resource utilization (such as intake of fresh water) in estuaries. In this study, we propose a general and analytical salt intrusion model inspired by Guo's general unit hydrograph theory for flood hydrograph prediction in a watershed. To derive a simple, general and analytical model of salinity distribution, we first make four hypotheses on the longitudinal salinity gradient based on empirical observations; we then derive a general unit hydrograph for the salinity distribution along a partially mixed or well-mixed estuary. The newly developed model can be well calibrated using a minimum of three salinity measurements along the estuary axis and does converge towards zero when the along-estuary distance approaches infinity asymptotically. The theory has been successfully applied to reproduce the salt intrusion in 21 estuaries worldwide, which suggests that the proposed method can be a useful tool for quickly assessing the spread of salinity under a wide range of riverine and tidal conditions and for quantifying the potential impacts of human-induced and natural changes.

Improving the accuracy of beef cattle methane inventories in Latin America and Caribbean countries

On-farm methane (CH4) emissions need to be estimated accurately so that the mitigation effect of recommended practices can be accounted for. In the present study prediction equations for enteric CH4 have been developed in lieu of expensive animal measurement approaches. Our objectives were to: (1) compile a dataset from individual beef cattle data for the Latin America and Caribbean (LAC) region; (2) determine main predictors of CH4 emission variables; (3) develop and cross-validate prediction models according to dietary forage content (DFC); and (4) compare the predictive ability of these newly-developed models with extant equations reported in literature, including those currently used for CH4 inventories in LAC countries. After outlier's screening, 1100 beef cattle observations from 55 studies were kept in the final dataset (∼ 50 % of the original dataset). Mixed-effects models were fitted with a random effect of study. The whole dataset was split according to DFC into a subset for all-forage (DFC = 100 %), high-forage (94 % ≥ DFC ≥ 54 %), and low-forage (50 % ≥ DFC) diets. Feed intake and average daily gain (ADG) were the main predictors of CH4 emission (g d−1), whereas this was feeding level [dry matter intake (DMI) as % of body weight] for CH4 yield (g kg−1 DMI). The newly-developed models were more accurate than IPCC Tier 2 equations for all subsets. Simple and multiple regression models including ADG were accurate and a feasible option to predict CH4 emission when data on feed intake are not available. Methane yield was not well predicted by any extant equation in contrast to the newly-developed models. The present study delivered new models that may be alternatives for the IPCC Tier 2 equations to improve CH4 prediction for beef cattle in inventories of LAC countries based either on more or less readily available data.

Prediction of enteric methane production and yield in sheep using a Latin America and Caribbean database

Methane (CH4) produced from enteric fermentation in ruminants has a noticeable impact on climate change. Prediction models are an alternative to current laborious and costly in vivo CH4 measurement techniques. The objectives of this study were to: (1) collate a database of individual sheep records from CH4 emission studies conducted in the Latin America and Caribbean (LAC) region; (2) identify key variables for predicting CH4 production (g/d) and CH4 yield [g/kg of dry matter intake (DMI)]; (3) develop and cross-validate these newly-developed models; and (4) compare models’ predictive ability with equations currently used to support national greenhouse gas (GHG) inventories in the LAC region. After removing outliers, the final database retained 219 individual sheep records from 11 studies, 48.2% of the original database. Models were developed using a sequential approach, by incrementally adding different variables with increasing complexity. Production and yield of CH4 were predicted by fitting mixed-effects models with a random effect of study. The predictive accuracy of fitted CH4 prediction models was evaluated using a leave-one-out cross-validation. Overall, increasing model complexity improved the predictive performance of CH4 production and yield equations. Feed intake was the most important predictor of sheep CH4 production. Our best-developed CH4 production models outperformed Tier 2 equations from the Intergovernmental Panel on Climate Change (IPCC) in the growing lambs and mature sheep subsets, whereas they performed slightly worse in the complete subset. Methane yield can be predicted using dietary forage content only, or with an increased complexity model combining body weight, feeding level, and dietary forage content. The use of the newly-developed models rather than IPCC Tier 2 equations can substantially improve the accuracy of GHG inventories from LAC countries.

Analyzing the Impact of Causal Factors on Political Management to Determine Sustainability Policy under Environmental Law: Enriching the Covariance-based SEMxi Model

This research aims to develop a causal relationship model on political management for sustainability policy formation under Thai environmental law by applying the best and valid model with a non-spurious property called the Covariance-based on Structural Equation Model with exogenous variables (Covariance-based SEMxi Model). This newly-developed model is in distinction with any past models as it is made effectively applicable to any sectors across areas. The model can also be utilized to design a long-term forecasting model with the ability to determine appropriate future scenarios. When assessing the covariance-based SEMxi model performance, the mean absolute percentage error (MAPE) and the root mean square error (RMSE) are estimated at 1.19% and 1.30%, respectively, in comparison of other models, including Gray-Autoregressive Integrated Moving Average Model (GM-ARIMA), Gray Model (GM), Back Propagation Neural Network (BP), Artificial Neural Natural Model (ANN), and Multiple Regression Model (MR). As for the results, this research reveals a direct impact of economic factors on environmental and social factors. In the meanwhile, social factors have a direct impact on environmental and economic factors. The research also indicates a direct effect on the environment with a maximal magnitude of 67%. Whereas a direct effect of social factors on the environment is detected at the magnitude of 55%. These effects are perceived to exceed the specified carrying capacity set by Thailand. In addition, a causal relationship is observed between economic and social factors, where the environment is found with the lowest error correction capability of only 5 percent. At the same time, economic and social factors are noticed with greater correction capability of 59% and 31%, respectively. This finding implies that the ecosystem will experience slow recovery whenever it deteriorates. Hence, the government must place a higher concentration on the environment, while different measures on environmental legislation should be closely controlled to contain any future damage. Besides, energy consumption must be managed not to exceed the established carrying capacity by simultaneously implementing both proactive and reactive measures. This process can be strengthened by optimizing the newly-introduced model produced by this work for a scenario design in policy management to attain sustainability.

A Design Method for Low-Pressure Venturi Nozzles

The purpose of this work is to provide empirical design models for low-pressure, subsonic Venturi nozzles. Experimentally validated simulations were used to determine the effect of nozzle geometry and operating conditions on the suction ratio (ratio of suction mass flow rate to motive mass flow rate) of low-pressure, subsonic Venturi nozzles, over a wide range of geometries and operating conditions, through a parametric study. The results of the parametric study were used to develop seven empirical models, each with a different range of applicability or calculating a different indicator of nozzle performance (i.e., suction ratio, momentum ratio, or dynamic pressure ratio), of the Venturi nozzles using a constrained multi-variable global optimization method. Of the seven empirical models, the best models were found to be those for low- (less than one) and high-suction ratios (greater than one), with mean absolute percentage errors of 5% and 18%, respectively. These empirical models provide a design tool for subsonic, low-pressure Venturi nozzles that is more than an order of magnitude more accurate than a governing equation approach or conventional flow head calculations. These newly-developed empirical models can be applied for initial nozzle design when precise suction ratios are required.

Prediction of enteric methane production and yield in dairy cattle using a Latin America and Caribbean database

Successful mitigation efforts entail accurate estimation of on-farm emission and prediction models can be an alternative to current laborious and costly in vivo CH4 measurement techniques. This study aimed to: (1) collate a database of individual dairy cattle CH4 emission data from studies conducted in the Latin America and Caribbean (LAC) region; (2) identify key variables for predicting CH4 production (g d−1) and yield [g kg−1 of dry matter intake (DMI)]; (3) develop and cross-validate these newly-developed models; and (4) compare models' predictive ability with equations currently used to support national greenhouse gas (GHG) inventories. A total of 42 studies including 1327 individual dairy cattle records were collated. After removing outliers, the final database retained 34 studies and 610 animal records. Production and yield of CH4 were predicted by fitting mixed-effects models with a random effect of study. Evaluation of developed models and fourteen extant equations was assessed on all-data, confined, and grazing cows subsets. Feed intake was the most important predictor of CH4 production. Our best-developed CH4 production models outperformed Tier 2 equations from the Intergovernmental Panel on Climate Change (IPCC) in the all-data and grazing subsets, whereas they had similar performance for confined animals. Developed CH4 production models that include milk yield can be accurate and useful when feed intake is missing. Some extant equations had similar predictive performance to our best-developed models and can be an option for predicting CH4 production from LAC dairy cows. Extant equations were not accurate in predicting CH4 yield. The use of the newly-developed models rather than extant equations based on energy conversion factors, as applied by the IPCC, can substantially improve the accuracy of GHG inventories in LAC countries.

Characteristics of the Gut Microbiome and IL-13/TGF-β1 Mediated Fibrosis in Post-Kasai Cholangitis of Biliary Atresia.

Aims: Cholangitis in biliary atresia (BA), which accelerates liver fibrosis progression, is among the most common serious complications after Kasai surgery; however, its etiology remains elusive. Gut microbiome migration may contribute to post-Kasai cholangitis. Further, there is no appropriate model of BA post-Kasai cholangitis for use in investigation of its pathogenesis.Methods: We explored the characteristics of gut microbiome in patients with BA before and after Kasai procedure based on 16S rDNA sequencing. We isolated the dominant strain from patient stool samples and established an in vitro model by infecting patient-derived liver organoids. Bulk RNA-seq was performed, and we conducted qPCR, ELISA, and western blot to explore the mechanism of fibrosis.Results: Gut microbiome diversity was lower in patients after, relative to before, Kasai procedure, while the relative abundance of Klebsiella was higher. Patients who developed cholangitis within 1 month after discharge tended to have simpler gut microbiome composition, dominated by Klebsiella. Klebsiella pneumoniae (KPN) was isolated and used for modeling. RNA-seq showed that BA liver organoids expressed markers of hepatic progenitor cells (KRT19, KRT7, EPCAM, etc.) and that organoids were more stable and less heterogeneous among individuals than liver tissues. After infection with KPN, gene expression patterns in BA liver organoids were enriched in pathways related to infection, apoptosis, and fibrosis. Preliminary experiments indicated the presence of IL-13/TGF-β1-mediated fibrosis in post-Kasai cholangitis.Conclusions: Our findings using a newly-developed model, demonstrate a key role for Klebsiella, and a potential mechanism underlying fibrosis in post-Kasai cholangitis, mediated by the IL-13/TGF-β1 pathway.

Experimental and numerical study on multiaxial creep behavior of 16MND5 steel at 700℃

In-vessel retention (IVR) is an effective strategy of ensuring the structural integrity of RPV under severe accidents. In the IVR condition, due to the geometric discontinuity of pressure vessel, multiaxial creep is the main form of failure of RPV. Moreover, 16MND5 steel undergoes a phase transition from bainite to austenite. In order to study the multiaxial creep failure mechanism, creep tests on different notched bar are carried out at 700℃. The influence of grain boundary precipitation on creep behaviors was studied by micro-structural observation. Furthermore, based on the Kachanov-Robotnov continuous damage model (CDM), the term of activation energy Q is adopted in the newly-developed model as the correction parameter that is used to study the damage evolution and multiaxial creep behaviors of 16NND5 steel. Finally, the good agreement is achieved between theoretical prediction and experimental results.

Particle/gas partitioning for semi-volatile organic compounds (SVOCs) in Level III multimedia fugacity models: Gaseous emissions

Atmospheric transport is a global-scale process that moves semi-volatile organic compounds (SVOCs) rapidly from source regions to remote locations, where these chemicals have never been produced or used. Particle/gas (P/G) partitioning of SVOCs during atmospheric transport governs wet and dry deposition, and thereby controls the efficiency and scope of long-range atmospheric transport and fate for these sorts of compounds. Previous work has shown that the assumption of steady state between particulate and gaseous phases in the atmosphere leads to model results that more closely match observations especially for compounds that strongly favor the particulate phase. Here, the practical application of steady-state P/G partitioning in the atmosphere in multimedia fugacity models is presented in greater detail. A method is developed whereby the fugacity of a chemical in the particle-phase is set equal to that in the gaseous phase (a pseudo equilibrium) but still maintains steady state of the chemical between air and aerosols in the atmosphere. This procedure greatly simplifies the application of multimedia fugacity models. Using this approach, a condition of steady state between air and aerosols is developed and applied in a Level III six-compartment six-fugacity model, which becomes a much simpler Level III six-compartment four-fugacity model. This newly-developed model is then applied to data observed during a monitoring program.

Ligand-dependent kinase activity of MERTK drives efferocytosis in human iPSC-derived macrophages

Removal of apoptotic cells by phagocytes (also called efferocytosis) is a crucial process for tissue homeostasis. Professional phagocytes express a plethora of surface receptors enabling them to sense and engulf apoptotic cells, thus avoiding persistence of dead cells and cellular debris and their consequent effects. Dysregulation of efferocytosis is thought to lead to secondary necrosis and associated inflammation and immune activation. Efferocytosis in primarily murine macrophages and dendritic cells has been shown to require TAM RTKs, with MERTK and AXL being critical for clearance of apoptotic cells. The functional role of human orthologs, especially the exact contribution of each individual receptor is less well studied. Here we show that human macrophages differentiated in vitro from iPSC-derived precursor cells express both AXL and MERTK and engulf apoptotic cells. TAM RTK agonism by the natural ligand growth-arrest specific 6 (GAS6) significantly enhanced such efferocytosis. Using a newly-developed mouse model of kinase-dead MERTK, we demonstrate that MERTK kinase activity is essential for efferocytosis in peritoneal macrophages in vivo. Moreover, human iPSC-derived macrophages treated in vitro with blocking antibodies or small molecule inhibitors recapitulated this observation. Hence, our results highlight a conserved MERTK function between mice and humans, and the critical role of its kinase activity in homeostatic efferocytosis.

Experimental and numerical study on viscously-damped outriggers with amplifying devices

A novel concept, labeled as amplified viscously-damped outrigger (AVDO) is proposed in this paper. It combines the viscously-damped outrigger (VDO) and steel amplifying devices to make the damper achieve higher energy dissipation capacity. Two newly-proposed configurations of AVDO were fabricated and compared with the conventional VDO by the dynamic cyclic loading test. The test results showed that AVDO can effectively amplify the deformation and energy dissipation of the damper. The change rule of the amplification factor and the difference between the experimental value and the theoretical value was analyzed, which highlighted that the deformation of components and the clearance in the pin joint had a great influence on the amplification of AVDO. Furthermore, a newly-developed model of joint clearance was used in the FE analysis of AVDO and validated with the experimental results. The stiffness of amplifying devices and outriggers and the joint clearance size effect on displacement amplification factor of AVDO were investigated. The amplifying device and the outrigger need to have sufficient stiffness to ensure the amplification effectiveness of AVDO, and it is suggested to reduce the clearance in the pin joint wherever applicable.

Effectiveness of a Care Delivery Model for High-Need Community-Dwelling Older Adults

The effectiveness of sufficient care coordination for high-need community-dwelling older adults has not been discussed. This study aimed to examine the effectiveness of a newly-developed care delivery model for high-need community-dwelling older adults. A cluster randomized controlled trial with repeated measures design was employed. A total of 145 high-need older adults participated in the study and were randomly assigned to either the intervention group or comparison group. A categorized list of care services based on the types of high-need older adults as the intervention allowed care coordinators to make adequate care service linkages. The intervention period ranged over 6 months with regulated home visits and assesssments. Functional ability, quality of life, depressive symptoms, and healthcare and social service utilizations were measured at baseline, and at 3 and 6 months into the intervention. The participants’ satisfaction with care delivery was measured at the end of 6-month intervention. Results showed that the intervention group had a better functional ability, a higher quality of life, reduced depressive symptoms, and more efficient healthcare and social service utilizations than the comparison group at both the 3-month and 6-month intervals (all p < .05). By the end of the 6-month study, the intervention group were more satisfied with the care service linkages than the comparison group (p < .05). The positive effects of providing a categorized list of care services for care coordinators to make service linkages have been evidenced by the outcomes. The promising findings supported a further longer-term implementation of the care delivery model.

Nationwide estimates of nitrogen and phosphorus losses via runoff from rice paddies using data-constrained model simulations

Quantifying the surface runoff losses of nitrogen (N) and phosphorus (P) at the regional scale is still challenging, mainly due to the model deficiencies and the lack of high-resolution data of agricultural management practices. Here, we re-evaluate N and P runoff losses from single, early and late rice systems in China, using a newly-developed model that was constrained by 127 rainfall-runoff events in 11 sites and driven by the fertilization and irrigation schemes from national surveys covering most of rice-producing provinces. Results show that national N and P runoff losses from rice paddies were 272.6 ± 101.2 Gg N yr−1 and 17.0 ± 6.4 Gg P yr−1, which were 38% and 12% less than previous model estimates, respectively, but 43% more than those of the first National Pollution Census Program (NPCP). The hotspots of N and P runoff losses were identified, most of which occurred in south China (60% of the total), generated during non-fertilization period (>65%), and took place in single rice system (∼50%). These losses might be mitigated by ∼90% through the increase in weir outlet height and the application of shallow-wet irrigation, but remain relatively stable even if optimizing fertilization scheme. The detailed assessment of mitigation potentials highlights an urgency in environmental policy regulation as well as farmers’ accessibility to advanced irrigation technologies, which is expected to inform promotion towards more effective non-point source pollution controls in China and other rice-producing countries.

A comparative study of fuzzy logic-based models for groundwater quality evaluation based on irrigation indices

AbstractGroundwater quality modelling plays an important role in water resources management decision making processes. Accordingly, models must be developed to account for the uncertainty inherent in the modelling process, from the sample measurement stage through to the data interpretation stages. Artificial intelligence models, particularly fuzzy inference systems (FIS), have been shown to be effective in groundwater quality evaluation for complex aquifers. In the current study, fuzzy set theory is applied to groundwater-quality related decision-making in an agricultural production context; the Mamdani, Sugeno, and Larsen fuzzy logic-based models (MFL, SFL, and LFL, respectively) are used to develop a series of new, generalized, rule-based fuzzy models for water quality evaluation using widely accepted irrigation indices and hydrological data from the Sarab Plain, Iran. Rather than drawing upon physiochemical groundwater quality parameters, the present research employs widely accepted agricultural indices (e.g., irrigation criteria) when developing the MFL, SFL and LFL groundwater quality models. These newly-developed models, generated significantly more consistent results than the United States Soil Laboratory (USSL) diagram, addressed the inherent uncertainty in threshold data, and were effective in assessing groundwater quality for agricultural uses. The SFL model is recommended as it outperforms both MFL and LFL in terms of accuracy when assessing groundwater quality using irrigation indices.

A unified extension of super-efficiency in additive data envelopment analysis with integer-valued inputs and outputs: an application to a municipal bus system

Conventional data envelopment analysis (DEA) may generate the non-integer targets for integer-valued inputs and outputs of decision-making units (DMUs). To derive the convincing projections, integer-valued DEA has attracted much attention. Given the integrality restriction, Du et al. (Eur J Oper Res 218(1):186–192, 2012) proposed the super-efficiency approach consisting of additive integer-valued and additive super-efficiency integer-valued models for the differentiation of efficient DMUs, thereby raising the discriminatory power. This paper extends their approach to develop a simpler but stricter version, which we refer to as the unified additive super-efficiency model. The newly-developed model has three advantages. First, the slacks of input excess, input saving, output shortage and output surplus can be directly computed in a single program to obtain the efficiencies of inefficient DMUs and super-efficiencies of efficient DMUs. Secondly, it suggests the strongly Pareto-efficient projections for efficient DMUs. Finally, the identified super-efficiencies allow for the property of continuity. A comparison of the proposed model, with Du et al.’s (2012) and standard additive super-efficiency approaches is discussed using a numerical example. In addition, the applicability of the proposed model is illustrated by a data set covering 13 bus companies operating in the municipal bus system of Taichung. Our work not only provides managerial insights into the primary sources of inefficiency and super-efficiency but also contributes to the current understanding of how super-efficiency would be effectively and accurately measured in the presence of integer-valued data.

Listen to your customer - how to manage your restaurant more effectively

ABSTRACTTo be a successful restaurant in today’s consumer-savvy environment poses challenges not encountered by businesses even as recently as twenty years ago. Customers are well-informed, have high expectations, and are quick to share their pleasure (or displeasure) across a range of social media platforms. Imagine if restaurateurs could identify the exact preferences of their target market, allowing them to tailor the dining experience to their customers’ precise needs, while optimizing resource use. And if there was such a model, would a restaurant use it? This article outlines the development and success of a newly-developed model, Customer-driven Restaurant Analysis (CDRA).

Validating an ethical decision-making model of assessment using authentic scenarios

An ethical decision-making model in assessment was newly developed using researcher-developed scenarios. In this article, the authors examined the usability of this newly-developed model by applying authentic scenarios involving ethical dilemmas proposed by classroom teachers. Thirty-three educators in a graduate-level online assessment course participated in the study to describe their overall ethical decision-making process with a real scenario that they or their colleagues experienced in classroom assessment. The current study provided evidence supporting the validation of the newly-developed ethical decision-making model using authentic scenarios. The model can be used for teacher professional development at the district level and in teacher education at the university level.