Validity Arguments for Diagnostic Assessment Using Automated Writing Evaluation

Two examples demonstrate an argument-based approach to validation of diagnostic assessment using automated writing evaluation (AWE). Criterion ®, was developed by Educational Testing Service to analyze students’ papers grammatically, providing sentence-level error feedback. An interpretive argument was developed for its use as part of the diagnostic assessment process in undergraduate university English for academic purposes (EAP) classes. The Intelligent Academic Discourse Evaluator (IADE) was developed for use in graduate EAP university classes, where the goal was to help students improve their discipline-specific writing. The validation for each was designed to support claims about the intended purposes of the assessments. We present the interpretive argument for each and show some of the data that have been gathered as backing for the respective validity arguments, which include the range of inferences that one would make in claiming validity of the interpretations, uses, and consequences of diagnostic AWE-based assessments

Coulomb repulsion versus cycloaddition: formation of anionic four-membered rings from sodium phosphaethynolate, Na(OCP)

Carbon dioxide and two equivalents of Na(OCP) form, in an equilibrium reaction, a CO2 adduct of the composition Na2(P2C3O4). The anion of this salt, [O2C–P(CO)2P]2−, is built up by a four-membered 1,3-diphosphetane-2,4-dione ring and a carboxylate unit attached to one of the phosphorus atoms. A remarkable π-delocalization was observed within the OCPCO moiety. The stepwise reaction mechanism leading to Na2(P2C3O4) was investigated with quantum chemical calculations. Accompanied by the release of CO2, Na2(P2C3O4) reacts with both 2-iodopropane and 4,4′,4′′-trimethoxytriphenylmethyl chloride to form four-membered cyclic anions. For comparison the analogous reactions were performed with Na(OCP) instead of Na2(P2C3O4) and the results are discussed in detail

Is the phosphaethynolate anion, (OCP)-, an ambident nucleophile? A spectroscopic and computational study.

The reactivity of Na(OCP) was investigated towards triorganyl compounds of the heavier group 14 elements (R3EX R = Ph or iPr; E = Si, Ge, Sn, Pb; X = Cl, OTf). In the case of E = Si two constitutional isomers were formed and characterised in situ: R3Si–O–C[triple bond, length as m-dash]P is the kinetic and R3Si–P[double bond, length as m-dash]C[double bond, length as m-dash]O is the thermodynamic product, representing experimental evidence of the ambident character of the (OCP)− anion. Applying theoretical calculations and spectroscopic methods, the compound previously reported as iPr3Si–O–C[triple bond, length as m-dash]P can now unambiguously be identified as iPr3Si–P[double bond, length as m-dash]C[double bond, length as m-dash]O. The heavier analogues form exclusively the phosphaketene isomer R3E–P[double bond, length as m-dash]C[double bond, length as m-dash]O (E = Ge, Sn, Pb). DFT calculations were performed to gain deeper insight into the bonding and thermodynamic stability of these compounds

Cyclo-oligomerization of isocyanates with Na(PH2) or Na(OCP) as “P−” anion sources

We show that the 2-phosphaethynolate anion, OCP−, is a simple and efficient catalyst for the cyclotrimerization of isocyanates. This process proceeds step-wise and involves five-membered heterocycles, namely 1,4,2-diazaphospholidine-3,5-dionide anions and spiro-phosphoranides as detectable intermediates, both of which were also found to be involved in the catalytic conversion. These species can be considered as adducts of a phosphide anion with two and four isocyanate molecules, respectively, demonstrating that the OCP− anion acts as a formal “P−” source. The interconversion between these anionic species was found to be reversible, allowing them to serve as reservoirs for unique phosphorus-based living-catalysts for isocyanate trimerization

Oxido-pincer complexes of copper(II) - An EXAFS and EPR study of mono- and binuclear [(pydotH)2CuCl2](n) (n=1 or 2)

The oxido-pincer ligand pydotH2 (2,6-bis(1-hydroxy-1-o-tolyl-ethyl-η2O,O′)pyridine) forms two different CuII containing complexes when prepared from anhydrous CuCl2. A combination of EPR spectroscopy and EXAFS allowed to structurally characterise the light-green dimer of the formula [(pydotH2)CuCl(μ-Cl)2ClCu(pydotH2)] and the penta-coordinate olive-green monomer [(pydotH2)CuCl2]. The molecular entities imply that the ligand remains protonated upon coordination. When dissolved in DMF both compounds form monomeric species [(pydotH2)CuCl2(DMF)] which could be characterised in detail by EPR, UV–Vis/NIR spectroscopy and electrochemical measurements. The assignments were supported by comparison with CuII complexes of the related ligands 2,6-bis(hydroxymethyl)pyridine (pydimH2) and 2,6-bis(1-hydroxy-1-methyl)pyridine (pydipH2)

Adaptive and intelligent mentoring to increase user attentiveness in learning activities

In the past decades intelligent mentoring systems have rapidly increased. In e-learning environment there has been an exponential growth in technological development environments and number of users that are addressed, hence an intelligent mentoring system should capture the user’s attention in order to improve results when focused in (e)learning tasks (i.e. serve both as a support of presence lessons and for distance form of studies – e-learning). It is important to note that the process of teaching-learning requires an interaction between the different actors involved: the tutor, the student, the expert domain and the learning environment or interface. In this paper we propose an innovative approach of an intelligent mentoring system that monitors the user’s biometric behaviour and measures his/her attention level during e-learning activities. Additionally, a machine learning categorisation model is presented that monitors students’ activity during school lessons. Nowadays computers are used as important working tools in many places, where we intend to use non-invasive methods of intelligent orientation through the observation of the user’s interaction with the computer.This work has been supported by: SENESCYT - Universidad do Minho and Secretaría de Educación Superior, Ciencia, Tecnología e Innovación within the Project: SENESCYT-SDFC-DSEFC-2017-2855-O; Part-funded by ERDF European Regional Development Fund and by National Funds through the FCT Portuguese Foundation for Science and Technology within project NORTE-01-0247-FEDER-017832. The work of Filipe Gonçalves is supported by a FCT grant with the reference ICVS-BI-2016-005

Synthesis and Characterization of Terminal [Re(XCO)(CO)2(triphos)] (X=N, P): Isocyanate versus Phosphaethynolate Complexes

The terminal rhenium(I) phosphaethynolate complex [Re(PCO)(CO)2(triphos)] has been prepared in a salt metathesis reaction from Na(OCP) and [Re(OTf)(CO)2(triphos)]. The analogous isocyanato complex [Re(NCO)(CO)2(triphos)] has been likewise prepared for comparison. The structure of both complexes was elucidated by X‐ray diffraction studies. While the isocyanato complex is linear, the phosphaethynolate complex is strongly bent around the pnictogen center. Computations including natural bond orbital (NBO) theory, natural resonance theory (NRT), and natural population analysis (NPA) indicate that the isocyanato complex can be viewed as a classic Werner‐type complex, that is, with an electrostatic interaction between the ReI and the NCO group. The phosphaethynolate complex [Re(PCO)(CO)2(triphos)] is best described as a metallaphosphaketene with a ReI–phosphorus bond of highly covalent character

An isolable magnesium diphosphaethynolate complex

The reaction of magnesium chloride with two equivalents of sodium phosphaethynolate, Na[OCP]·(dioxane)2.5 (1), yields a magnesium diphosphaethynolate complex, [(THF)4Mg(OCP)2] (3). The formation of compound 3 goes through a monosubstituted chloromagnesium phosphaethynolate Mg(OCP)Cl (2). The structure of 3 was determined via a single crystal X-ray diffraction study. For comparison, we also report the structure of a monomeric sodium phosphaethynolate complex, [Na(OCP)(dibenzo-18-crown-6)] (4)