A Study of Snippet Length and Informativeness: Behaviour, Performance and User Experience

The design and presentation of a Search Engine Results Page (SERP) has been subject to much research. With many contemporary aspects of the SERP now under scrutiny, work still remains in investigating more traditional SERP components, such as the result summary. Prior studies have examined a variety of different aspects of result summaries, but in this paper we investigate the influence of result summary length on search behaviour, performance and user experience. To this end, we designed and conducted a within-subjects experiment using the TREC AQUAINT news collection with 53 participants. Using Kullback-Leibler distance as a measure of information gain, we examined result summaries of different lengths and selected four conditions where the change in information gain was the greatest: (i) title only; (ii) title plus one snippet; (iii) title plus two snippets; and (iv) title plus four snippets. Findings show that participants broadly preferred longer result summaries, as they were perceived to be more informative. However, their performance in terms of correctly identifying relevant documents was similar across all four conditions. Furthermore, while the participants felt that longer summaries were more informative, empirical observations suggest otherwise; while participants were more likely to click on relevant items given longer summaries, they also were more likely to click on non-relevant items. This shows that longer is not necessarily better, though participants perceived that to be the case - and second, they reveal a positive relationship between the length and informativeness of summaries and their attractiveness (i.e. clickthrough rates). These findings show that there are tensions between perception and performance when designing result summaries that need to be taken into account

Diets of Desert Cottontail on Prairie Dog Colonies in Western South Dakota

Fecal pellets of desert cottontail (Sylvaligus audubonii) were collected during 1981 in May, June, July, August and September for dietary analysis to determine composition of forage plants. Four plants made up 70 percent of the total diet. Forage plants, in order of significance, were western wheat grass (Pascopyrum smithii), fescue (Festuca spp), squirretail (Sitanion hystrix), and plains muhly (Muhlenbergia cuspidata). The most common forb in diets was scarlet globemallow (Sphaeralcea coccinea) and the shrub, plains pricklypear (Opuntia polyacantha). Grasses in the diet ranged from 65 percent to 88 percent while forbs and shrubs ranged from 11 percent to 31 percent, 1 percent to 6 percent, respectively. Botanical composition in the plant community varied throughout the season

Transfer Learning for Multi-language Twitter Election Classification

Both politicians and citizens are increasingly embracing social media as a means to disseminate information and comment on various topics, particularly during significant political events, such as elections. Such commentary during elections is also of interest to social scientists and pollsters. To facilitate the study of social media during elections, there is a need to automatically identify posts that are topically related to those elections. However, current studies have focused on elections within English-speaking regions, and hence the resultant election content classifiers are only applicable for elections in countries where the predominant language is English. On the other hand, as social media is becoming more prevalent worldwide, there is an increasing need for election classifiers that can be generalised across different languages, without building a training dataset for each election. In this paper, based upon transfer learning, we study the development of effective and reusable election classifiers for use on social media across multiple languages. We combine transfer learning with different classifiers such as Support Vector Machines (SVM) and state-of-the-art Convolutional Neural Networks (CNN), which make use of word embedding representations for each social media post. We generalise the learned classifier models for cross-language classification by using a linear translation approach to map the word embedding vectors from one language into another. Experiments conducted over two election datasets in different languages show that without using any training data from the target language, linear translations outperform a classical transfer learning approach, namely Transfer Component Analysis (TCA), by 80% in recall and 25% in F1 measure

Diets of Cattle in North Central South Dakota

This study was conducted over a two year period during the summer months on the Grand River National Grasslands near Lemmon South Dakota on a 2,510 ha pasture to determine cattle diets. Cattle feces were collected monthly near each of 8 permanent water tanks located throughout the pasture. Microhistological analysis of cattle feces was used to identify and quantify diets by plant species. Eight common plant species comprised the greatest portion of the diet. Grasses and grass-like plants accounted for 84 percent to 99 percent of the diets with sedges common in spring (79%) and early summer (53%). Key forage species were, sedges (Carex spp), blue grama (Bouteloua gracilis), needle and thread (Hesperostipa comata) and green needlegrass (Nassella viridula) that comprised 82 percent of the diet. These plants are key forage species for monitoring seasonal grazing on the grasslands. Forbs ranged from less than 1 percent to 14 percent. Shrubs were a minor component of the diet making up less than 1 percent. Similarity indices changed throughout the season and ranged from 0 to 99 percent, indicating that some plants were highly selected or avoided by cattle (low similarities) and other plant species were consumed in the same proportions as available on the grassland. Rank order correlation indicated seasonal selectivity with an overall correlation of 0.75

Long-term safety of siltuximab in patients with idiopathic multicentric Castleman disease: a prespecified, open-label, extension analysis of two trials.

BACKGROUND:Siltuximab is recommended by international consensus as a first-line treatment for idiopathic multicentric Castleman disease on the basis of durable efficacy and safety data. This study was done to assess the long-term safety and activity of siltuximab over up to 6 years of treatment. METHODS:This study is a prespecified open-label extension analysis of a phase 1 trial (NCT00412321) and a phase 2 trial (NCT01024036), done at 26 hospitals worldwide. Patients in both studies were at least 18 years old with histologically confirmed, symptomatic Castleman disease. This extension study enrolled 60 patients who completed the previous trials without disease progression on siltuximab. Patients received siltuximab infusions of 11 mg/kg every 3 weeks (which could be extended to 6 weeks) for up to 6 years. Descriptive statistics were used to summarise the data. No formal hypothesis testing was performed. The primary endpoint was the safety of siltuximab, assessed at each dosing cycle. The study was registered with ClinicalTrials.gov, number NCT01400503 and with EudraCT, number 2010-022837-27. FINDINGS:Patient enrolment into the phase 1 trial was from June 20, 2005, to Sept 15, 2009, and enrolment into the phase 2 trial was from Feb 9, 2010, to Feb 3, 2012. Patients were enrolled in this long-term extension from April 1, 2011, to Jan 15, 2014. Median follow-up was 6 years (IQR 5·11-7·76). Median treatment duration, from the beginning of the previous trials to the end of the present study, was 5·5 years (IQR 4·26-7·14). Siltuximab was well tolerated; however, adverse events of grade 3 or worse were reported in 36 (60%) of 60 patients with the most common being hypertension (eight [13%]), fatigue (five [8%]), nausea (four [7%]), neutropenia (four [7%]), and vomiting (three [5%]). 25 (42%) patients reported at least one serious adverse event, which most commonly was an infection (eight [13%]). Only two serious adverse events, polycythaemia and urinary retention, were considered related to siltuximab treatment. 18 patients discontinued before study completion, either to receive siltuximab locally (eight) or because of progressive disease (two), adverse events (two), or other reasons (six). No deaths were reported. INTERPRETATION:These results show that siltuximab is well tolerated long term and provides important evidence for the feasibility of the life-long use required by patients with idiopathic multicentric Castleman disease. FUNDING:Janssen R&D and EUSA Pharma

An integrated approach to rotorcraft human factors research

As the potential of civil and military helicopters has increased, more complex and demanding missions in increasingly hostile environments have been required. Users, designers, and manufacturers have an urgent need for information about human behavior and function to create systems that take advantage of human capabilities, without overloading them. Because there is a large gap between what is known about human behavior and the information needed to predict pilot workload and performance in the complex missions projected for pilots of advanced helicopters, Army and NASA scientists are actively engaged in Human Factors Research at Ames. The research ranges from laboratory experiments to computational modeling, simulation evaluation, and inflight testing. Information obtained in highly controlled but simpler environments generates predictions which can be tested in more realistic situations. These results are used, in turn, to refine theoretical models, provide the focus for subsequent research, and ensure operational relevance, while maintaining predictive advantages. The advantages and disadvantages of each type of research are described along with examples of experimental results

Unbiased Comparative Evaluation of Ranking Functions

Eliciting relevance judgments for ranking evaluation is labor-intensive and costly, motivating careful selection of which documents to judge. Unlike traditional approaches that make this selection deterministically, probabilistic sampling has shown intriguing promise since it enables the design of estimators that are provably unbiased even when reusing data with missing judgments. In this paper, we first unify and extend these sampling approaches by viewing the evaluation problem as a Monte Carlo estimation task that applies to a large number of common IR metrics. Drawing on the theoretical clarity that this view offers, we tackle three practical evaluation scenarios: comparing two systems, comparing $k$ systems against a baseline, and ranking $k$ systems. For each scenario, we derive an estimator and a variance-optimizing sampling distribution while retaining the strengths of sampling-based evaluation, including unbiasedness, reusability despite missing data, and ease of use in practice. In addition to the theoretical contribution, we empirically evaluate our methods against previously used sampling heuristics and find that they generally cut the number of required relevance judgments at least in half.Comment: Under review; 10 page

An analysis of query difficulty for information retrieval in the medical domain

We present a post-hoc analysis of a benchmarking activity for information retrieval (IR) in the medical domain to determine if performance for queries with different levels of complexity can be associated with different IR methods or techniques. Our analysis is based on data and runs for Task 3 of the CLEF 2013 eHealth lab, which provided patient queries and a large medical document collection for patient centred medical information retrieval technique development. We categorise the queries based on their complexity, which is defined as the number of medical concepts they contain. We then show how query complexity affects performance of runs submitted to the lab, and provide suggestions for improving retrieval quality for this complex retrieval task and similar IR evaluation tasks

Identifying Predictors of Medication Adherence in Adult Patients with Asthma: A Social Problem-Solving Approach

Asthma is a chronic respiratory illness that has become major public health concern due to its rapid increase in prevalence and increasing economic burden. Asthma management, which includes asthma control, perceived control of asthma and medication adherence, has been documented to be extremely poor. One of the main reasons for poor management includes low rates of medication adherence. The primary goal of this research study was to identify factors related to medication adherence that can eventually be integrated into clinical practice. Identifying these factors would help increase adherence rates and decrease the burden of asthma on individuals as well as the entire population. The current study examined how individual variables are related to medication adherence in patients with asthma. Research has indicated that patients with high perceived stress are less likely to adhere to a prescribed medication regimen. Social problem-solving, which is the affective, cognitive and behavioral way individuals approach real world problems, is related to the management of various chronic conditions and may moderate the relationship between perceived stress and adherence outcomes. Adult asthma patients for this study were recruited from two different medical sites: an allergy and asthma private practice located in New Jersey and Drexel Pulmonary Medicine located in Philadelphia, PA. Self-report data was collected from participants (N = 104) including demographic information, asthma control, perceived control of asthma, perceived stress, social problem-solving behaviors and medication adherence. Additional patient information was gathered using patient medical and pharmacy records. Bivariate correlational analyses demonstrated positive associations between perceived stress and dysfunctional social problem-solving tendencies and negative associations between perceived stress and self-report adherence. Lower perceived stress was also associated with more adaptive social problem-solving tendencies and higher asthma control. Lower perceived control of asthma was associated with the dysfunctional social problem-solving dimensions and higher pharmacy reports of adherence. Analyses also revealed relationships between higher self-report adherence and more adaptive problem-solving abilities. A hierarchical regression analysis revealed that lower perceived control of asthma was predictive of higher pharmacy refill adherence rates. Social problem-solving did not significantly moderate the relationship between perceived stress and medication adherence. Exploratory analyses indicated that lower self-reports of adherence, lower perceived control of asthma, and more maladaptive problem-solving tendencies were all predictive of higher perceived stress. Additionally, a one-way analysis of variance (ANOVA) was conducted to examine differences among racial and ethnic groups. Individuals who identified as White reported greater self-report adherence, less perceived stress, better social problem-solving abilities, higher perceived control of asthma, and better objective control of asthma, as compared to other racial and ethnic groups. Results suggest integrative medical and psychosocial treatments should be adapted for individuals of various racial and ethnic backgrounds. Interventions that target social problem-solving abilities and perceived stress may be particularly beneficial for improving patient’s ability and perceived ability to successfully manage their asthma.M.S., Psychology -- Drexel Unviersity, 201