Can constrained relevance feedback and display strategies help users retrieve items on mobile devices?

Searching online information resources using mobile devices is affected by small screens which can display only a fraction of ranked search results. In this paper we investigate whether the search effort can be reduced by means of a simple user feedback: for a screenful of search results the user is encouraged to indicate a single most relevant document. In our approach we exploit the fact that, for small display sizes and limited user actions, we can construct a user decision tree representing all possible outcomes of the user interaction with the system. Examining the trees we can compute an upper limit on relevance feedback performance. In this study we consider three standard feedback algorithms: Rocchio, Robertson/Sparck-Jones (RSJ) and a Bayesian algorithm. We evaluate them in conjunction with two strategies for presenting search results: a document ranking that attempts to maximize information gain from the user’s choices and the top-D ranked documents. Experimental results indicate that for RSJ feedback which involves an explicit feature selection policy, the greedy top-D display is more appropriate. For the other two algorithms, the exploratory display that maximizes information gain produces better results. We conducted a user study to compare the performance of the relevance feedback methods with real users and compare the results with the findings from the tree analysis. This comparison between the simulations and real user behaviour indicates that the Bayesian algorithm, coupled with the sampled display, is the most effective. Extended version of “Evaluating Relevance Feedback Algorithms for Searching on Small Displays, ” Vishwa Vinay, Ingemar J. Cox, Natasa Milic-Frayling, Ken Wood published in the proceedings of ECIR 2005, David E. Losada, Juan M. Fernández-Luna (Eds.), Springer 2005, ISBN 3-540-25295-9     

Creating Better Learners Through Learning Science: A Sample of Methods

This article proposes the incorporation of learning science into the programming and operation of public libraries. Learning science, a multidisciplinary field spanning cognitive science, psychology, neuroscience, economics, anthropology, and linguistics, has identified proven methods for enhancing learning at any age. The article highlights some of the tools and insights that are most relevant to libraries in their role as centers for informal learning.     

Handwriting isolated cursive letters in young children: Effect of the visual trace deletion

This study assesses the handwriting of isolated cursive letters in five-year-old children and the effect of a modification in visual feedback. Sixty-four children copied twelve cursive letters with an inking pen and a non-inking pen. Reducing visual feedback decreased the mean number of penlifts, and increased mean velocity and fluency. However, it increased the size of the letters (trajectory length) and reduced their quality. We suggest that processing visual feedback of the emerging visual trace may interrupt the fluency of the movement, while writing without seeing the trace may place greater emphasis on motor control and the use of somatosensory feedback. This study supplies reflection about sensory feedback and the moment when it should be provided in handwriting instruction. Practitioners should be aware that variation in the writing environment (surface, tools …) modifies sensory feedback and affects handwriting learning (gesture and outcome) in different manner.     

The effect of anticipated achievement feedback on students' semantic processing as indicated by the N400 cloze effect

The present study examined the effects of anticipated achievement feedback on students' semantic processing on the neural level, using event-related brain potentials (ERPs). Participants (N = 79) anticipated either self-referential or normative achievement feedback regarding an announced upcoming test. Additionally, their performance expectations (low vs. no expectations) were orthogonally manipulated. Subsequently, students' on-line semantic processing was assessed by measuring the N400 cloze effect, a component in the EEG signal of which the amplitude is associated with semantic processing. Within the low performance-expectation condition, no effect of anticipated feedback on semantic processing was found. Within the no-performance-expectation condition, participants anticipating self-referential feedback showed a more widely distributed N400 cloze effect than participants anticipating normative feedback. The results confirmed the hypothesis that the mere expectation of a particular type of feedback can affect students' semantic processes.     

Implementing Conferences in College English Writing Class:The Effects of the Negotiated Input

The current study is to examine the interactional effects of writing conferences focusing on negotiated patterns of revi?sion in a college English writing class. Fifteen participants were required to w...     

An Overall Study on Automated Writing Evaluation

Automated Writing Evaluation (AWE) program is designed to provide instant scores based on automated writing scor?ing engine along with diagnostic feedback. Five main AWE programs are introduced, four i...     

社会体育指导员岗位素质应然与实然的调查研究

社会体育指导员作为社会体育发展的主要力量,提升自身的岗位素质成为社会体育指导员健身指导水平的保障。论文主要采用文献资料法、访谈法与问卷调查法,对社会体育指导员应有和实有的品质能力、技能能力、行为能力进行调查,研究认为,社会体育指导员的“应然”岗位素质均得到认可,而“实然”的岗位素质掌握程度不够理想,智能化设备使用能力成为短板,研究能为社会体育指导员在岗位上所应具备的岗位素质提供借鉴。     

运算放大器工作状态的判断及分析

在电子技术教学中,分析运算放大器系统时,应根据运算放大器系统的反馈情况,判断它的工作状态;分析工作状态时,要充分考虑运放系统是处于线性区还是饱和区。线性区可按虚短或虚地原则处理,饱和时不能按虚短原则处理,应用“虚短”和“虚地”时应注意“虚短”是“虚地”的特殊形式。     

A coach’s political use of video-based feedback: a case study in elite-level academy soccer

This paper examines the video-based pedagogical practices of Terry (pseudonym), a head coach of a professional junior academy squad. Data were collected through 6 in-depth, semi-structured interviews and 10 field observations of Terry’s video-based coaching in situ. Three embracing categories were generated from the data. These demonstrated that Terry’s video-based coaching was far from apolitical. Rather, Terry strategically used performance analysis technologies to help fulfil various objectives and outcomes that he understood to be expected of him within the club environment. Kelchtermans’ micropolitical perspective, Callero’s work addressing role and Groom et al.’s grounded theory were primarily utilised to make sense of Terry’s perceptions and actions. The findings point to the value of developing contextually grounded understandings of coaches’ uses of video-based performance analysis technology. Doing so could better prepare coaches for this aspect of their coaching practice.     

信息反馈与汉语修辞

言语交际。信息传递，不都是简单的、单向的、固定的、一次性的。更多的。因此而更有现实意义和理论价值的，乃是那些复杂的、双向的、随机的、多次传递方能完成的。因此，判定某处修辞是成功的还是失败的，必须考察其在一个复杂的修辞流程中所起的作用，视其所造成的到底是正反馈还是负反馈。如若其所造成的是正反馈，那么，不管它多么生动、形象，都是失败的修辞；如若造成的是负反馈，那么，不管它多么朴拙、背谬，都是成功的修辞。