Response rate is not an effective mediator of learned stimulus equivalence in pigeons

We explored response rate as a possible mediator of learned stimulus equivalence. Five pigeons were trained to discriminate four clip art pictures presented during a 10-sec discrete-trial fixed interval (FI) schedule: two paired with a one-pellet reinforcer, which supported a low rate of responding, and two paired with a nine-pellet reinforcer, which supported a high rate of responding. After subjects associated one stimulus from each of these pairs with a discriminative choice response, researchers presented two new clip art stimuli during a 10-sec FI: one trained with a differential reinforcement of low rate schedule (DRL) after the FI and the other trained with a differential reinforcement of high rate schedule (DRH) after the FI. Each of the stimuli that were withheld during choice training was later shown to see if the choice responses would transfer to these stimuli. The results suggest that response rate alone does not mediate learned stimulus equivalence.     

Children with autism illuminate the role of social intention in word learning

To what extent do children with autism (AD) versus typically developing children (TD) rely on attentional and intentional cues to learn words? Four experiments compared 17 AD children (M age=5.08 years) with 17 language- and 17 mental-age-matched TD children (M ages=2.57 and 3.12 years, respectively) on nonverbal enactment and word-learning tasks. Results revealed variability in all groups, but particularly within the AD group. Performance on intention tasks was the most powerful predictor of vocabulary in the AD group but not in the TD groups. These findings suggest that word learning cannot be explained exclusively by either attentional or intentional processes, and they provide evidence of a special role for intentional understanding in the vocabulary development of AD children.     

The Long Decay Model of One-Dimensional Projectile Motion

This article introduces a research study on student model formation and development in introductory mechanics. As a point of entry, I present a detailed analysis of the Long Decay Model of one-dimensional projectile motion. This model has been articulated by Galileo (in De Motu) and by contemporary students. Implications for instruction are discussed.

---

ENGLISH UNIVERSITIES, ADDITIONAL FEE INCOME AND ACCESS AGREEMENTS: THEIR IMPACT ON WIDENING PARTICIPATION AND FAIR ACCESS

ABSTRACT:  This paper argues that the introduction of access agreements following the establishment of the Office for Fair Access (OFFA) has consolidated how English higher education institutions (HEIs) position themselves in the marketplace in relation to widening participation. However, the absence of a national bursary scheme has led to obfuscation rather than clarification from the perspective of the consumer. This paper analyses OFFA's 2008 monitoring report and a sample of twenty HEIs' original 2006 and revised or updated access agreements (2008) to draw conclusions about the impact of these agreements on notions of 'fair access' and widening participation. The authors conclude that, unsurprisingly in an increasingly market-driven system, institutions use access agreements primarily to promote enrolment to their own programmes rather than to promote system-wide objectives. As a consequence of this marketing focus, previous differences between pre-1992 and post-1992 institutions in relation to widening participation and fair access are perpetuated, leading to both confusion for consumers and an inequitable distribution of bursary and other support mechanisms for the poorest applicants to HE.     

药学无机化学教学方法改革初探

本文分析了无机化学课程体系和内容的现状,从教学方法、实验教学、教材建设、双语教学和改进教学水平等几个方面提出了一些对无机化学课程改革的想法和措施。     

Quality and relevance of domain-specific search: A case study in mental health

When searching for health information, results quality can be judged against available scientific evidence: Do search engines return advice consistent with evidence based medicine? We compared the performance of domain-specific health and depression search engines against a general-purpose engine (Google) on both relevance of results and quality of advice. Over 101 queries, to which the term ‘depression’ was added if not already present, Google returned more relevant results than those of the domain-specific engines. However, over the 50 treatment-related queries, Google returned 70 pages recommending for or against a well studied treatment, of which 19 strongly disagreed with the scientific evidence. A domain-specific index of 4 sites selected by domain experts was only wrong in 5 of 50 recommendations. Analysis suggests a tension between relevance and quality. Indexing more pages can give a greater number of relevant results, but selective inclusion can give better quality.     

Retrieving and classifying instances of source code plagiarism

Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents.     

谈谈植物学野外实习质量控制

在分析植物学野外实习教学质量存在问题的基础上,探讨了植物野外实习教学质量控制与管理的必要性,提出了植物野外实习教学质量控制与提高的途径及做法,以便植物实习管理、参与人员参考。     

The effect of network size on intra-network knowledge processes

This paper addresses a neglected topic in the knowledge management literature: how the size of a network of actors affects the nature of intra-network social relations and knowledge processes. It makes a theoretical contribution to developing understanding in this area drawing on a range of literatures including practice-based perspectives on knowledge, the literature on the embeddedness of social relations, and relevant knowledge management literature. The central focus of this paper is on the relationship between network size, network density, and how these variables affect intra-network knowledge processes. It suggests that as network size increases network density is likely to decrease (as it becomes problematic for the actors in such networks to retain strong ties with a significant proportion of the network's members), which it will be suggested has significant ramifications for intra-network knowledge processes. This paper concludes by reflecting on the implications of the ideas developed for network-based forms of organizing, and innovation processes.