Browsing by Author "Schaal, Markus"

Now showing 1 - 5 of 5

Open Access
Detecting user types in object ranking decisions
(ACM, 2009-10) Lu, X.; Schaal, Markus; Adalı, S.; Raju, A. K.
With the emergence of Web 2.0 applications, where information is not only shared across the internet, but also syndicated, evaluated, selected, recombined, edited, etc., quality emergence by collaborative effort from many users becomes crucial. However, users may have low expertise, subjective views, or competitive goals. Therefore, we need to identify cooperative users with strong expertise and high objectivity. As a first step towards this aim, we propose criteria for user type classification based on prior work in psychology and derived from observations in Web 2.0. We devise a statistical model for many different user types, and detection methods for those user types. Finally, we evaluate and demonstrate both model and detection methods by means of an experimental setup. Copyright 2009 ACM.
Open Access
Dynamics of commitment and contribution quality in collaborative communities
(IEEE, 2007-11) Schaal, Markus; Eren, Y.
It is well-known that commitment is an important ingredient for contributions of high quality. With the internet heading towards being an actionable social space, rather than a collection of web-sites, the issue of quality becomes crucial for sharing knowledge and action in collaborative scenarios. We propose a case study for the investigation of the influence of time, user feedback and interface complexity on contribution quality. We plan to exploit different online user groups across two different temporal phases for the evaluation.
Open Access
Evaluation of ontology enhancement tools
(Springer, 2005-10) Spiliopoulou, M.; Schaal, Markus; Müller, R. M.; Brunzel, M.
Mining algorithms can enhance the task of ontology establishment but methods are needed to assess the quality of their findings. Ontology establishment is a long-term interactive process, so it is important to evaluate the contribution of a mining tool at an early phase of this process so that only appropriate tools are used in later phases. We propose a method for the evaluation of such tools on their impact on ontology enhancement. We model impact as quality perceived by the expert and as statistical quality computed by an objective function. We further provide a mechanism that juxtaposes the two forms of quality. We have applied our method on an ontology enhancement tool and gained some interesting insights on the interplay between perceived impact and statistical quality. © 2006 Springer-Verlag.
Open Access
A graph based approach to estimating lexical cohesion
(ACM, 2008) Gürkök, Hayrettin; Karamuftuoglu, Murat; Schaal, Markus
Traditionally, information retrieval systems rank documents according to the query terms they contain. However, even if a document may contain all query terms, this does not guarantee that it is relevant to the query. The query terms can occur together in the same document, but may have been used in different contexts, expressing separate topics. Lexical cohesion is a characteristic of natural language texts, which can be used to determine whether the query terms are used in the same context in the document. In this paper we make use of a graph-based approach to capture term contexts and estimate the level of lexical cohesion in a document. To evaluate the performance of our system, we compare it against two benchmark systems using three TREC document collections. Copyright 2008 ACM.
Open Access
Notification value in personal travel asisstance
(Verlag Dr. Kovac, 2007) Schaal, Markus; Lenz, H. J.; Müller, R. M.