Using model-based scaffolds to support students solving context-based chemistry problems

ABSTRACT

Context-based learning aims to make learning more meaningful by raising meaningful problems. However, these types of problems often require reflection and thinking processes that are more complex and thus more difficult for students, putting high demands on students’ problem-solving capabilities. In this paper, students’ approaches when solving context-based chemistry problems and effects of systematic scaffolds are analysed based on the Model of Hierarchical Complexity. Most answers were initially assigned to the lowest level of the model; higher levels were reached without scaffolds only by few students and by most students with scaffolds. The results are discussed with regard to practical implications in terms of how teachers could make use of context-based tasks and aligned scaffolds to help students in this activity.     

Dynamische Probleml?sekompetenz

This article is about the importance and validity of dynamic problem solving (DPS) in predicting technical problem solving performances. In addition to DPS, fluid intelligence and technical knowledge were included in the study. Assessing DPS and fluid intelligence simultaneously also allowed for testing the empirical distinction between both constructs. Results are based on data of a sample of car mechatronics (n?=?129) and electronics technicians (n?=?88) and showed that DPS and fluid intelligence were empirically separable. In the first sample (electronics technicians) DPS explained technical problem solving performance best, although fluid intelligence showed incremental validity too. In the second sample (car mechatronics) fluid intelligence was weakly related to the criterion whereas DPS was not at all. When technical knowledge was added to the prediction, both DPS and fluid intelligence did not predict technical problem solving performance. However, in the sample of the electronics technicians fluid intelligence indirectly affected the criterion through technical knowledge. A discussion of the somewhat contradictory results, the different results patterns in the two samples and a theoretical explanation of the results are provided.     

Computer-based assessment of Complex Problem Solving: concept, implementation, and application

Complex Problem Solving (CPS) skills are essential to successfully deal with environments that change dynamically and involve a large number of interconnected and partially unknown causal influences. The increasing importance of such skills in the 21st century requires appropriate assessment and intervention methods, which in turn rely on adequate item construction, delivery, and scoring. The lack of assessment tools, however, has slowed down research on and understanding of CPS. This paper first presents the MicroDYN framework for assessing CPS, which is based on linear structural equation systems with input and output variables and opaque relations among them. Second, a versatile assessment platform, the CBA Item Builder, which allows the authoring, delivery, and scoring of CPS tasks for scientific and educational purposes is introduced. Third, we demonstrate the potential of such a tool for research by reporting an experimental study illustrating the effect of domain specific content knowledge on performance in CPS tasks both on an overall performance and on a process level. The importance of accessible and versatile technical platforms not only for assessment and research but also for intervention and learning are discussed with a particular focus on educational contexts.     

Gender Cue Effects in Children’s Pronoun Processing: A Longitudinal Eye Tracking Study

ABSTRACT

Children struggle with the resolution of pronouns during reading, but little is known about the sources of their difficulties. We conducted a longitudinal eye tracking experiment with 70 children in the final years of primary school. The children read sentences with a contextual resolution preference in which gender was either an informative resolution cue for the pronoun or not. We were interested in children’s processing of the pronoun and their resolution preferences, as well as the effects of individual differences of Grade level and reading skill. Children’s resolution ability improved with age, and good readers were more accurate than poor readers. In the eye-tracking measures, we found strong individual differences related to reading skill: Children with good reading skill took more time to read the pronoun region when pronoun gender was informative, suggesting that good readers make better use of the available information at the pronoun than poor readers.     

A novel μ-fluidic whole blood coagulation assay based on Rayleigh surface-acoustic waves as a point-of-care method to detect anticoagulants

A universal coagulation test that reliably detects prolonged coagulation time in patients, irrespective of the anticoagulant administered, has not been available to date. An easily miniaturised, novel μ-fluidic universal coagulation test employing surface acoustic waves (SAW) is presented here. SAW was employed to instantly mix and recalcify 6 μl citrated whole blood and image correlation analysis was used to quantify clot formation kinetics. The detection of clinically relevant anticoagulant dosing with old anticoagulants (unfractionated heparin, argatroban) and new anticoagulants (dabigatran, rivaroxaban) has been tested and compared to standard plasma coagulation assays. The applicability of this novel method has been confirmed in a small patient population. Coagulation was dose-proportionally prolonged with heparin, argatroban, dabigatran, and rivaroxaban, comparable to standard tests. Aspirin and clopidogrel did not interfere with the SAW-induced clotting time (SAW-CT), whereas the strong GPIIb/IIIa-inhibitor abciximab did interfere. Preliminary clinical data prove the suitability of the SAW-CT in patients being treated with warfarin, rivaroxaban, or dabigatran. The system principally allows assessment of whole blood coagulation in humans in a point-of-care setting. This method could be used in stroke units, emergency vehicles, general and intensive care wards, as well as for laboratory and home testing of coagulation.     

Football practice with youth players in the “Footbonaut”

In today’s leading football training centres, state-of-the-art performance diagnostic systems such as the “Footbonaut” allow controlled and standardized assessments of physical and mental components of agility, e.g. speed of action and ball control, that are considered to be decisive for talent identification and development. However, effects of induced physical and mental strain on performing football-specific practice patterns remain to be elucidated, particularly in youth players, and, thus, characterize the purpose of this study. 33 randomly assigned competitive football players (U14 to U16) performed a standardized Footbonaut practice pattern (i.e. 20 balls randomly drawn at 50?km/h each), prior to and immediately after either mentally demanding tasks (MDT; n?=?11; continuous Vienna Test System’s Stroop task and determination test), physically demanding tasks (PDT; n?=?11; consisted of 4?×?4?min of football-specific high-intensity intervals with 3?min of active recovery in between) or a control condition (CON; n?=?11). Continuous heart rates (HR) as well as self-perceptions of fatigue were assessed. Main findings revealed performances for speed of action (p?=?0.44; f?=?0.01) and ball control (p?=?0.15; f?=?0.03) that were not modulated in the face of induced physical and mental strain as indicated by increased HR following PDT (p?<?0.001; d?>?0.8), or in the face of increased self-perceptions of fatigue following PDT and MDT (both p?<?0.001; both d?>?0.8) compared to CON. This is in line with a suggested talent factor and previous reports on motivational trade-off aspects in youth players. However, the present study’s short-timed practice patterns make it difficult to reliably compare a measuring sensitivity to complex football-specific movement behavioural and technical proficiencies with respect to mental and physical strain of longer-lasting football games and, thus, need further investigation in favour of improving talent identification and development using the Footbonaut.