Events play a prominent role in our lives, such that many social media documents describe or are related to some event.Organizing social media documents with respect to events thus seems a promising approach to better manage and organize the ever-increasing amount of content in social media applications. A challenge is to automatize this process so that incoming documents can be assigned to their corresponding event without any user intervention. We present a system that is able to classify a stream of social media data into a growing and evolving set of events. By doing this, we successfully address two key problems that arise in this context: i) scaling to the data sizes and rates encountered in social media applications, and ii) tackling the new event detection problem, i.e. the problem of determining whether an incoming data item belongs to a new or a known event. We successfully address these problems by i) including a candidate retrieval step that retrieves a set of event candidates that the incoming data point is likely to belong to and ii) by including a function trained using machine learning techniques to determine whether the incoming data item belongs to the top scoring candidate or rather to a new event. We show that our system addresses the above mentioned challenging issues successfully and that it outperforms other state-of-the-art approaches in terms of quality and scalability.

The mechanical transmission of motion, which is observable in gears' turning direction (TD) and turning speed (TS) can be understood as part of the core concept "force and motion". Previous studies have suggested that most children before the age of nine have naïve concepts of gears' TD and TS. However, these studies relied on children's explanation data and might have therefore underestimated young children's potential. Moreover, these studies did not examine whether preschoolers can overcome their naïve concepts through teaching. Recently, educators have proposed guided play as an educational approach that combines children's play with teacher guidance in a purposefully designed environment. We conducted two subsequent studies. In Study 1, we investigated the children's (naïve) concepts of gears' TD and TS with a cross-sectional approach using a nonverbal test procedure. This study comprised 248 children aged 5-10 years and 73 adults. The results showed that the proportion of children with adequate concepts increased with age. More specifically, 7-to 8-year-olds differed significantly from 5-to 6year-olds, indicating a developmental shift around this age. However, naïve concepts of TS were more persistent with age than naïve concepts of TD. Altogether, the results indicated the potential to foster 5-to 6-year-olds' concepts of both TD and TS in an intervention. Thus, in Study 2, we

According to the German educational standards, students should be familiar with problem-solving as a general mathematical competency by the end of grade 4. Non-routine word problems are suitable tasks for mathematical problem-solving in elementary mathematics classes. They are characterized by the fact that the problemsolver cannot simply use well-trained algorithmic calculating procedures (Rasch, 2001). As a result, many students struggle with word problems in mathematics, especially with non-routine word problems (Hohn, 2012). Representation plays a central role in the process of problem-solving. It involves representing a problem situation adequately, constructing a mental model and comparing it in a dynamic and iterative process with the information externalized in the representation (Schnotz et al, 2011). This study aims to shed light on teacher-provided representations as cognitive tools for students when working on non-routine word problems. In an experimental study, we examined a sample of 67 primary school students who worked on six non-routine word problems with provided representations. The tasks were accompanied by a table or a drawing. Furthermore, the tables and drawings differed with regard to the amount of information provided. Statistical data analysis generated, among other findings, two results: Overall solution rates were low (10 to 24%). Tables and drawings facilitated the solution process differently depending on the type of word problem. Consequences for subsequent future research are discussed.

Results: At first few children used a Mass theory to explain their reasoning. However, after being confronted with counterevidence for the asymmetrical constructions, children changed their explanation and applied a Mass theory. More children in the play group with the highest degree of scaffolding, i.e., material + verbal scaffolds, acquired a Mass theory compared to the other groups. Fluid as well as crystallized intelligence contributed to children's acquisition of a Mass theory. Discussion: Counterevidence can support children in their acquisition of a Mass theory. A playful intervention with scaffolding supports children even more.

Introducing kindergarten children to the engineering design process (EDP) is an important objective of early STEM education. Studies indicate that children often miss the crucial steps of testing and optimising during the EDP and do not persist in making solutions better. The present study explores how children's goal awareness, self-evaluation ability, domain-specific content knowledge, spatial skills and intelligence relate to their persistence, testing and optimising behaviour and to solution quality. In a standardized procedure, 41 children (4 to 7 years) in Germany worked on an engineering task in the domain of gears. The engineering process was videotaped, children's testing and optimising, solution quality, goal awareness, self-evaluation, and task persistence were rated with a coding scheme and with interviewer questions. Domain-specific content knowledge, mental rotation ability and figural reasoning were measured with standardized tests. Correlational analyses indicated that goal awareness was positively related to solution quality. However, most children required support by the interviewer to retrieve the goal specifications. Moreover, children's self-evaluation was negatively related to task persistence. Most children were satisfied with their first solution, even when it did not meet the requirements. Our findings emphasize the important role of teachers in helping children to tackle challenges with the EDP.