A cognitive study of learning to program in introductory programming courses.

Programming is notoriously hard for novices to learn and a substantial number of learners fail in introduction to programming courses. It is not just a UK problem: a number of multi-institutional and multi-national studies reveal that the problem is well-known and is widespread. There is no general agreement about the causes or the remedies. The major factors which can be hypothesised as a cause of this phenomenon are: learners' psychology; teaching methods; complexity of programming. In this study, learners' common mistakes, bugs, misconceptions, frequencies and type of errors (syntactic and semantic) in the early stages of learning programming were studied. Noticing the patterns of rationales behind novices' mistakes swayed the study toward investigating novices' mental ability which was found to have a great effect on their learning performance. It was observed that novices reported a recognisable set of models of program execution each of which was logically acceptable as a possible answer and it appeared that some students even used these models systematically. It was suspected that the intellectual strategies behind their reasoning could have been built up from their programming background knowledge and it was surprising when it was found that some of those novices had not even seen a program before. A diagnostic questionnaire was designed that apparently examined a student's understanding of assignments and sequence but in fact was capturing the reasoning strategy behind their interpretation of each question, regardless of a correct or wrong answer. The questionnaire was administered in the first week of an introductory programming course, without giving any explanation of what the questions were about. A full response from most participants was received, despite the fact that the questions were unexplained. Confronted with a simple program, about half of novices seem to spontaneously invent and consistently apply a mental model of program execution. They were called the consistent subgroup. The other half are either unable to build a model or to apply one consistently. They were called the inconsistent subgroup. The first group perform very much better in their end-of-course examination than the rest. Meta-analysis of the results of six experiments in UK and Australia confirmed a strong effect of consistency on success which is highly significant (p < 0:001). A strong eect persisted in every group of candidates, sliced by background factors of programming experience (with/ without), relevant programming experience(with/without), and prior programming course (with/without) which might be thought to have had an effect on success. This result confirms that consistency is not simply provided by prior programming background. Despite the tendency in institutions to rely on students' prior programming background as a positive predictor for success, this study revealed that prior programming education did not have a noticeable eect on novices' success. A weak positive eect of prior programming experience was observed overall which appeared to be driven by one experiment with a programming-skilful population. This study shows that students in the consistent subgroup have the ability to build a mental model, something that follows rules like a mechanical construct. It also seems that when programming skill is measured by a weak assessment mechanism, the eect of consistency on success is reduced

MAT-732: EXPERIMENTAL STUDY ON THE CAPACITY OF BARRIER DECK ANCHORAGE IN MTQ PL-3 BARRIER REINFORCED WITH HM-GFRP BARS WITH HEADED ENDS

A recent design work conducted at Ryerson University on PL-3 bridge barrier has led to an economical glass fibre reinforced polymer (GFRP) bar detailing for sustainable construction. A PL-3 barrier wall of 27.6 m length was constructed using the proposed GFRP bar configuration, incorporating the use of V-Rod headed-end bars. The proposed barrier configuration was recently crash tested to qualify its use in Canada’s highway bridges. Then, wall segments of this barrier were tested under static loading to-collapse to determine their structural behavior, crack pattern and ultimate load carrying capacity under simulated vehicle impact load. Test results led to establishing two Standard drawings by Ontario Ministry of Transportation (MTO) for use by consulting engineers and contractors. The crash-tested barrier dimensions were identical to those specified by Ministry of Transportation of Quebec (MTQ) for PL-3 barrier except that the base of the barrier was 40 mm short and the deck slab is of 200 mm thickness, leading to reduction in the GFRP embedment depth into the deck slab. As such, Ryerson University research team proposed an experimental program to ensure that the resistance of barrier-deck junction, with the reduced width of barrier base and thickness of the deck slab, is greater of equal to the specified factored design load applied to the barrier wall simulating vehicle impact. This paper summarizes the experimental program to justify the modified barrier design to fit with MTQ barrier and deck slab dimensions and experimental findings when compared to the available factored applied moments specified in CHBDC of 2006 for the design of barrier-deck junction. Correlation between the experimental findings and the factored applied moments from CHBDC equivalent vehicle impact forces resulting from the finite-element modelling of the barrier-deck system was conducted followed by recommendations for use of the proposed design in highway bridges in the Province of Quebec

Functional Independence Measure in Iran: A Confirmatory Factor Analysis and Evaluation of Ceiling and Floor Effects in Traumatic Brain Injury Patients

Background: The functional independence measure (FIM) is one of the most important assessment instruments for motor and cognitive dependence in rehabilitation medicine; however, there is little data about its confirmatory factor analysis (CFA) and ceiling/floor effects from other countries and also in Iranian patients. Objectives: The aim of this study was to evaluate a two-factor model (motor and cognitive independence as latent variables) and ceiling/floor effects for FIM in Iranian patients with traumatic brain injuries (TBI). Patients and Methods: In this cross-sectional study, 185 subacute TBI patients were selected from emergency and neurosurgery departments of Poursina Hospital (the largest trauma hospital in northern Iran, Rasht) using the consecutive sampling method and were assessed for functional independence. Results: The results of this study showed that the floor effect was not observed; however, ceiling effects were observed for the FIM total score and its subscales. The confirmatory factor analysis showed that the chi-square/df ratio was 2.8 for the two-factor structure and the fit indices for this structural model including root mean square error of approximation (RMSEA) = 0.099, normed fit index (NFI) = 0.96, tucker lewis index (TLI) = 0.97, comparative fit index (CFI) = 0.97 were close to standard indices. Conclusions: Although ceiling effects should be considered for rehabilitation targets, the two-factor model of FIM (motor and cognitive independence) has an eligible fitness for Iranian patients with TBI

Programming: Predicting student success early in CS1. A re-validation and replication study

This paper describes a large, multi-institutional revalidation study conducted in the academic year 2015-16. Six hundred and ninetytwo students participated in this study, from 11 institutions (ten institutions in Ireland and one in Denmark). The primary goal was to validate and further develop an existing computational prediction model called Predict Student Success (PreSS). In doing so, this study addressed a call from the 2015 ITiCSE working group (the second Grand Challenge ), to systematically analyse and verify previous studies using data from multiple contexts to tease out tacit factors that contribute to previously observed outcomes . PreSS was developed and validated in a longitudinal study conducted over a three year period (twelve years previous from 2004- 06). PreSS could predict with near 80% accuracy, how a student would likely perform on an introductory programming module. Notably this could be achieved at a very early stage in the module. This paper describes a revalidation of the original PreSS model on a significantly larger multi-institutional data set twelve years after its initial development and looks at recent research on additional factors that may improve the model. The work involved the development of a fully automated end-to-end tool, which can predict student success early in CS1, with an accuracy of 71%. This paper describes, in detail the PreSS model, recent research, pilot studies and the re-validation and replication study of the PreSS model

The Relationship Between Serum Levels of Interleukins 6, 8, 10 and Clinical Outcome in Patients With Severe Traumatic Brain Injury

Background: Clinical outcome in patients with severe traumatic brain injury (TBI) depends on both primary and secondary brain injuries. Neuroinflammation is an important secondary mechanism, which occurs by releasing interleukins (ILs). Increased levels of ILs may affect clinical outcome following TBI. Objectives: This study aimed to determine the relationship between the serum levels of interleukins 6, 8 and 10 and clinical outcome in patients with severe TBI 6 months after injury. Patients and Methods: In a descriptive-analytical study, 44 patients with GCS ≤ 8 (Glasgow coma scale) and age ≥ 14 years were included. Their blood samples were collected at first 6 hours after injury. Clinical outcome was determined based on GOS (Glasgow Outcome Scale) at 6 months after head injury. Serum levels of interleukins 6, 8 and 10 were measured using the ELISA method. Spearman's rho, independent T-Test, and Mann-Whitney Test were used for data analysis. Results: Comparing the serum levels of interleukins in two groups with favorable and unfavorable clinical outcomes showed that the mean serum levels of interleukins 6 and 8 in group with favorable outcome was 85.2 ± 51.6 and 52.2 ± 31.9, respectively lower than those of group with unfavorable outcome with 162.3 ± 141.1 and 173.6 ± 257.3 (P < 0.03) and (P < 0.01). Conclusions: Increased serum levels of interleukins 6 and 8 as a predictive marker might be associated with unfavorable clinical outcome in patients with severe TBI

Decay constants of heavy pseudoscalar mesons from QCD sum rules

We revisit the sum-rule extraction of the decay constants of the D, Ds, B, and Bs mesons from the two-point correlator of heavy-light pseudoscalar currents. We use the operator product expansion for this correlator expressed in terms of the MSbar heavy-quark mass, for which the perturbative expansion exhibits a reasonable convergence. Our main emphasis is laid on the control over the uncertainties in the decay constants, related both to the input QCD parameters and to the limited accuracy of the method of sum-rules. This becomes possible due to the application of our procedure of extracting hadron observables that involves as novel feature dual thresholds depending on the Borel parameter. For charmed mesons, we find the decay constants f_D=206.2\pm 7.3(OPE)\pm 5.1(syst) MeV and f_Ds=245.3\pm 15.7(OPE)\pm 4.5(syst) MeV. For beauty mesons, the decay constants turn out to be extremely sensitive to the precise value of mb(mb). By requiring our sum-rule estimate to match the average of the lattice results for f_B, a very accurate value mb(mb)=4.245\pm 0.025 GeV is extracted, leading to f_B=193.4\pm 12.3(OPE)\pm 4.3(syst) MeV and f_Bs=232.5\pm 18.6(OPE)\pm 2.4(syst) MeV.Comment: 12 page

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe