A Survey on Visual Query Systems in the Web Era (extended version) <s> Statement of the method <s> Visual query systems (VQSs) are query systems for databases that use visual representations to depict the domain of interest and express related requests. VQSs can be seen as an evolution of query languages adopted into database management systems; they are designed to improve the effectiveness of the human?computer communication. Thus, their most important features are those that determine the nature of the human?computer dialogue. In order to survey and compare existing VQSs used for querying traditional databases, we first introduce a classification based on such features, namely the adopted visual representations and the interaction strategies. We then identify several user types and match the VQS classes against them, in order to understand which kind of system may be suitable for each kind of user. We also report usability experiments which support our claims. Finally, some of the most important open problems in the VQS area are described. <s> BIB001 </s> A Survey on Visual Query Systems in the Web Era (extended version) <s> Statement of the method <s> Faceted metadata and navigation have become major topics in library science, information retrieval and Human-Computer Interaction (HCI). This work surveys a range of extant approaches in this design space, classifying systems along several relevant dimensions. We use that survey to analyze the organization of data and its querying within faceted browsing systems. We contribute formal entity-relationship (ER) and relational data models that explain that organization and relational query models that explain systems' browsing functionality. We use these types of models since they are widely used to conceptualize data and to model back-end data stores. Their structured nature also suggests ways in which both the models and faceted systems might be extended. <s> BIB002
A survey about a particular object must determine the relevant features of the object with respect to a particular purpose. Once the features have been determined, the next step is to find the possible values of these features. Finally, we have to determine the best combinations of the pairs (feature, value) for the particular purpose. Usually, we can extract the relevant features and their possible values from published papers about the object, by assuming features in their entirety or by adapting them to new perspectives appearing after the papers have been published. Moreover, we can add features detected by ourselves which were not previously included in any paper. The survey develops through several steps, which are usually interspersed. In the first step, a complete search of sources determines the candidate papers that deal with the object. In the second step, the relevant features of the object with respect to the particular purpose are determined. Our object in this survey are the visual query systems with the purpose of facilitating querying databases to non expert in Computer Science users. The survey BIB001 reviews up to 80 references from 1975 until 1996 used for querying traditional databases. For this survey, we have searched for papers related with VQS from 1997 to date and we have found 194 candidate papers. Next, we have discarded papers about query languages but without visual part (122) and papers about natural language query languages(8) because they deserve a separate survey. In the remaining 64 works, we have determined sets of 'similar papers' and we have discarded all but one paper in each set. A set of similar papers is composed of several papers built on different aspects of the same idea for a VQS. They also include preliminary versions of the VQS which were later on subsumed by more complete journal publications. We have found 30 similar papers. So, we have discarded 122 + 8 + 30 papers, that is, 160 papers. As a result, the number of papers reviewed in this survey is 34. In Table 1 we summarise all these figures. As for relevant features, we have extracted the following from the survey of Catarci BIB001 : 1. Visual representation adopted to present the reality of interest 2. Visual representation adopted to express queries The values of this feature have been determined from the work BIB001 and from other papers, such as BIB002 , where the faceted option appeared. For answering the question of this paper, we have added the following features