Personalised Search Time Prediction using Markov Chains

For improving the effectiveness of Interactive Information Retrieval (IIR), a system should minimise the search time by guiding the user appropriately. As a prerequisite, in any search situation, the system must be able to estimate the time the user will need for finding the next relevant document. In this paper, we show how Markov models derived from search logs can be used for predicting search times, and describe a method for evaluating these predictions. For personalising the predictions based upon a few user events observed, we devise appropriate parameter estimation methods. Our experimental results show that by observing users for only 100 seconds, the personalised predictions are already significantly better than global predictions

The effect of membership in the European Community on Maltese pharmacists

On 16th July, 1990, Malta applied formally to become a full member of the European Community. There is no doubt that membership of the European Community will have a considerable effect on the lives of all the people and in particular the professions. Pharmacists in Malta will also be effected by this, and the profession has already reported to the Government on this situation, after closely analysing the situation prevailing in other EC member states as regards the pharmacy profession (Pharmacy in the European Community, 1990).peer-reviewe

Validating simulated interaction for retrieval evaluation

A searcher’s interaction with a retrieval system consists of actions such as query formulation, search result list interaction and document interaction. The simulation of searcher interaction has recently gained momentum in the analysis and evaluation of interactive information retrieval (IIR). However, a key issue that has not yet been adequately addressed is the validity of such IIR simulations and whether they reliably predict the performance obtained by a searcher across the session. The aim of this paper is to determine the validity of the common interaction model (CIM) typically used for simulating multi-query sessions. We focus on search result interactions, i.e., inspecting snippets, examining documents and deciding when to stop examining the results of a single query, or when to stop the whole session. To this end, we run a series of simulations grounded by real world behavioral data to show how accurate and responsive the model is to various experimental conditions under which the data were produced. We then validate on a second real world data set derived under similar experimental conditions. We seek to predict cumulated gain across the session. We find that the interaction model with a query-level stopping strategy based on consecutive non-relevant snippets leads to the highest prediction accuracy, and lowest deviation from ground truth, around 9 to 15% depending on the experimental conditions. To our knowledge, the present study is the first validation effort of the CIM that shows that the model’s acceptance and use is justified within IIR evaluations. We also identify and discuss ways to further improve the CIM and its behavioral parameters for more accurate simulations

Aphids associated with shrubs, herbaceous plants and crops in the Maltese Archipelago (Hemiptera, Aphidoidea)

A survey of the aphids associated with Maltese shrubs, herbaceous plants and crops was carried out. Sixty six aphid species were recorded from more than 90 species of host plants. Forty eight aphids were recorded from the Maltese islands for the fi rst time bringing the total number of aphid species known from these islands to 99. New records include: Acyrthosiphon lactucae, A. pisum, Anoecia vagans, Aphis alienus, A. euphorbiae, A. hederae, A. lambersi, A. multifl orae, A. nasturtii, A. parietariae, A. picridicola, A. ruborum, A. sedi, Aulacorthum solani, Brachycaudus helichrysi, Capitophorus sp. nr. similis, Clypeoaphis suaedae, Cryptomyzus korschelti, Dysaphis apiifolia, D. foeniculus, D. pyri, D. tulipae, Hyadaphis coriandri, H. foeniculi, H. passerinii, Hyperomyzus lactucae, Idiopterus nephrelepidis, Macrosiphoniella absinthii, M. artemisiae, M. sanborni, Macrosiphum euphorbiae, Ma. rosae, Melanaphis donacis, Metopolophium dirhodum, Pterochloroides persicae, Rectinasus buxtoni, Rhopalosiphum maidis, R. padi, R. rufi abdominale, Schizaphis graminum, Semiaphis dauci, Sipha maydis, Sitobion avenae, S. fragariae, Therioaphis alatina, Uroleucon inulae, U. hypochoeridis and U. sonchi. Of these 99 aphid species, 58 are of economic importance and 16 are alien introductions. For 15 of the aphid species, a total of 22 new host-plant records are made. Ten species of ants were found attending 18 aphid species.peer-reviewe

The impact of result diversification on search behaviour and performance

Result diversification aims to provide searchers with a broader view of a given topic while attempting to maximise the chances of retrieving relevant material. Diversifying results also aims to reduce search bias by increasing the coverage over different aspects of the topic. As such, searchers should learn more about the given topic in general. Despite diversification algorithms being introduced over two decades ago, little research has explicitly examined their impact on search behaviour and performance in the context of Interactive Information Retrieval (IIR). In this paper, we explore the impact of diversification when searchers undertake complex search tasks that require learning about different aspects of a topic (aspectual retrieval). We hypothesise that by diversifying search results, searchers will be exposed to a greater number of aspects. In turn, this will maximise their coverage of the topic (and thus reduce possible search bias). As a consequence, diversification should lead to performance benefits, regardless of the task, but how does diversification affect search behaviours and search satisfaction? Based on Information Foraging Theory (IFT), we infer two hypotheses regarding search behaviours due to diversification, namely that (i) it will lead to searchers examining fewer documents per query, and (ii) it will also mean searchers will issue more queries overall. To this end, we performed a within-subjects user study using the TREC AQUAINT collection with 51 participants, examining the differences in search performance and behaviour when using (i) a non-diversified system (BM25) versus (ii) a diversified system (BM25+xQuAD) when the search task is either (a) ad-hoc or (b) aspectual. Our results show a number of notable findings in terms of search behaviour: participants on the diversified system issued more queries and examined fewer documents per query when performing the aspectual search task. Furthermore, we showed that when using the diversified system, participants were: more successful in marking relevant documents, and obtained a greater awareness of the topics (i.e. identified relevant documents containing more novel aspects). These findings show that search behaviour is influenced by diversification and task complexity. They also motivate further research into complex search tasks such as aspectual retrieval -- and how diversity can play an important role in improving the search experience, by providing greater coverage of a topic and mitigating potential bias in search results

Looking for opportunities : challenges in professional procurement search

Procurement legislation stipulates that information about the goods, services, or works, that tax-funded authorities wish to purchase are made publicly available in a procurement contract notice. However, for businesses wishing to tender for such competitive opportunities, finding relevant procurement contract notices presents a challenging professional search task. In this talk, we will provide an overview of procurement search and then describe the challenges in addressing the related search and recommendation tasks

Laryngeal lymphoma : the high and low grades of rare lymphoma involvement sites

The larynx is an extremely rare site of involvement by lymphomatous disease.We present two cases of isolated laryngeal high-grade and another low-grade lymphoma, together with a literature review of laryngeal lymphoma management.peer-reviewe

Study of the impacts of droplets deposited from the gas core onto a gas-sheared liquid film

The results of an experimental study on droplet impactions in the flow of a gas-sheared liquid film are presented. In contrast to most similar studies, the impacting droplets were entrained from film surface by the gas stream. The measurements provide film thickness data, resolved in both longitudinal and transverse coordinates and in time together with the images of droplets above the interface and images of gas bubbles entrapped by liquid film. The parameters of impacting droplets were measured together with the local liquid film thickness. Two main scenarios of droplet-film interaction, based on type of film perturbation, are identified; the parameter identifying which scenario occurs is identified as the angle of impingement. At large angles an asymmetric crater appears on film surface; at shallow angles a long, narrow furrow appears. The most significant difference between the two scenarios is related to possible impact outcome: craters may lead to creation secondary droplets, whereas furrows are accompanied by entrapment of gas bubbles into the liquid film. In addition, occurrence of partial survival of impacting droplet is reported