Measuring and improving data quality of media collections for professional tasks

Carrying out research tasks on data collections is hampered, or even made impossible, by data quality issues of different types, such as incompleteness or inconsistency, and severity. We identify research tasks carried out by professional users of data collections that are hampered by inherent quality issues. We investigate what types of issues exist and how they influence these research tasks. To measure the quality perceived by professional users, we develop a quality metric. This allows us to measure the suitability of the data quality for a chosen user ta

Impact Analysis of OCR Quality on Research Tasks in Digital Archives

Humanities scholars increasingly rely on digital archives for their research in place of time-consuming visits to physical archives. This shift in research methodology has the hidden cost of working with digi- tally processed historical documents: how much trust can a scholar place in noisy representations of source texts? In a series of interviews with historians about their use of digital archives, we found that scholars are aware that optical character recognition (OCR) errors may bias their results. They were, however, unable to quantify this bias or to indicate what information they would need to estimate it. Based on the interviews and a literature study, we provide a classification scheme relating schol- arly research tasks to their specific OCR-induced uncertainty and the data required for more reliable uncertainty estimations. We conducted a use case study on a national newspaper archive with example research tasks. From this we learned what data is typically available in digital archives and how it could be used to reduce and/or assess the uncer- tainty in result sets. We conclude that the current knowledge situation on the users’ side as well as on the tool makers and data providers’ side is insufficient and needs further research to be improved

Second Screen Interactions for Automatically Web-Enriched Broadcast Video

Including hypermedia in broadcast video combines content formatted for a lean-forward medium (the Web) with a lean-back one (TV) to form a hybrid medium. We identify four challenges for interacting with and experiencing this new medium. We discuss the role a second screen may play in addressing these challenges

Is it a bird or is it a crow? The influence of presented tags on image tagging by non-expert users

Cultural heritage institutes often make use of tags to facilitate searching their collections. While professionals associated with these institutes are able to add high quality descriptions to objects in the collections, both their time and their areas of expertise are limited. As a result, online tagging by non-professional users is more frequently becoming deployed to increase the number of tags. When these users are asked to tag objects in the collection, they can be confronted with tags submitted by other users. These tags may be of varying quality and present in differing numbers, both of which may influence users' tagging behavior. We report on a study on the impact of presenting different types of tags on the quality and quantity of tags added by users. We conclude that there is no difference in the quality and quantity of added tags in all experimental conditions, with the exception of the condition in which incorrect tags were presented. In this condition, the quality of the tags added by users decreased. We discuss the implications of these findings on the design of tagging interfaces

Measuring the Effectiveness of Gamesourcing Expert Oil Painting Annotations

Tasks that require users to have expert knowledge are diffi- cult to crowdsource. They are mostly too complex to be carried out by non-experts and the available expert

Intricate visibility effects from resolved emission of young stellar objects: the case of MWC158 observed with the VLTI

In the course of our VLTI young stellar object PIONIER imaging program, we have identified a strong visibility chromatic dependency that appeared in certain sources. This effect, rising value of visibilities with decreasing wavelengths over one base, is also present in previous published and archival AMBER data. For Herbig AeBe stars, the H band is generally located at the transition between the star and the disk predominance in flux for Herbig AeBe stars. We believe that this phenomenon is responsible for the visibility rise effect. We present a method to correct the visibilities from this effect in order to allow "gray" image reconstruction software, like Mira, to be used. In parallel we probe the interest of carrying an image reconstruction in each spectral channel and then combine them to obtain the final broadband one. As an illustration we apply these imaging methods to MWC158, a (possibly Herbig) B[e] star intensively observed with PIONIER. Finally, we compare our result with a parametric model fitted onto the data.Comment: 14 pages, 7 figure

Gamesourcing Expert Painting Annotations

Online collections provided by museums are increasingly opened for contributions from users outside the museum. These initiatives are mostly targeted at obtaining tags describing aspects of artworks that are common knowledge. This does not require the contributors to have specific skills or knowledge. Museums, however, are also interested in obtaining very specific information about the subject matter of their artworks. We present a game that can help to collect expert knowledge by enabling non-expert users to perform an expert annotation task. This is achieved by simplifying the expert task and providing a sufficient level of annotation support to the users. In a user study we could prove the usefulness of our approach

Crowd vs Experts: Nichesourcing for Knowledge Intensive Tasks in Cultural Heritage

The results of our exploratory study provide new insights to crowdsourcing knowledge intensive tasks. We designed and performed an annotation task on a print collection of the Rijksmuseum Amsterdam, involving experts and crowd workers in the domain-specific description of depicted flowers. We created a testbed to collect annotations from flower experts and crowd workers and analyzed these in regard to user agreement. The findings show promising results, demonstrating how, for given categories, nichesourcing can provide useful annotations by connecting crowdsourcing to domain expertise

Sculpting the disk around T Cha: an interferometric view

(Abridged) Circumstellar disks are believed to be the birthplace of planets and are expected to dissipate on a timescale of a few Myr. The processes responsible for the removal of the dust and gas will strongly modify the radial distribution of the dust and consequently the SED. In particular, a young planet will open a gap, resulting in an inner disk dominating the near-IR emission and an outer disk emitting mostly in the far-IR. We analyze a full set of data (including VLTI/Pionier, VLTI/Midi, and VLT/NaCo/Sam) to constrain the structure of the transition disk around TCha. We used the Mcfost radiative transfer code to simultaneously model the SED and the interferometric observations. We find that the dust responsible for the emission in excess in the near-IR must have a narrow temperature distribution with a maximum close to the silicate sublimation temperature. This translates into a narrow inner dusty disk (0.07-0.11 AU). We find that the outer disk starts at about 12 AU and is partially resolved by the Pionier, Sam, and Midi instruments. We show that the Sam closure phases, interpreted as the signature of a candidate companion, may actually trace the asymmetry generated by forward scattering by dust grains in the upper layers of the outer disk. These observations help constrain the inclination and position angle of the outer disk. The presence of matter inside the gap is difficult to assess with present-day observations. Our model suggests the outer disk contaminates the interferometric signature of any potential companion that could be responsible for the gap opening, and such a companion still has to be unambiguously detected. We stress the difficulty to observe point sources in bright massive disks, and the consequent need to account for disk asymmetries (e.g. anisotropic scattering) in model-dependent search for companions.Comment: Removed the word "first" in the abstract of the paper: "obtained with the first 4-telescope combiner (VLTI/Pionier)