Connecting high school physics experiences,outcome expectations,physics identity,and physics career choice: A gender study

This study explores how students' physics identities are shaped by their experiences in high school physics classes and by their career outcome expectations. The theoretical framework focuses on physics identity and includes the dimensions of student performance, competence, recognition by others, and interest. Drawing data from the Persistence Research in Science and Engineering (PRiSE) project, which surveyed college English students nationally about their backgrounds, high school science experiences, and science attitudes, the study uses multiple regression to examine the responses of 3,829 students from 34 randomly selected US colleges/universities. Confirming the salience of the identity dimension for young persons' occupational plans, the measure for students' physics identity used in this study was found to strongly predict their intended choice of a physics career. Physics identity, in turn, was found to correlate positively with a desire for an intrinsically fulfilling career and negatively with a desire for personal/family time and opportunities to work with others. Physics identity was also positively predicted by several high school physics characteristics/experiences such as a focus on conceptual understanding, real‐world/contextual connections, students answering questions or making comments, students teaching classmates, and having an encouraging teacher. Even though equally beneficial for both genders, females reported experiencing a conceptual focus and real‐world/contextual connections less frequently. The explicit discussion of under‐representation of women in science was positively related to physics identity for female students but had no impact for male students. Surprisingly, several experiences that were hypothesized to be important for females' physics identity were found to be non‐significant including having female scientist guest speakers, discussion of women scientists' work, and the frequency of group work. This study exemplifies a useful theoretical framework based on identity, which can be employed to further examine persistence in science, and illustrates possible avenues for change in high school physics teaching. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 978–1003, 2010     

Semantic Similarity Search on Semistructured Data with the XXL Search Engine

Query languages for XML such as XPath or XQuery support Boolean retrieval: a query result is a (possibly restructured) subset of XML elements or entire documents that satisfy the search conditions of the query. This search paradigm works for highly schematic XML data collections such as electronic catalogs. However, for searching information in open environments such as the Web or intranets of large corporations, ranked retrieval is more appropriate: a query result is a ranked list of XML elements in descending order of (estimated) relevance. Web search engines, which are based on the ranked retrieval paradigm, do, however, not consider the additional information and rich annotations provided by the structure of XML documents and their element names.This article presents the XXL search engine that supports relevance ranking on XML data. XXL is particularly geared for path queries with wildcards that can span multiple XML collections and contain both exact-match as well as semantic-similarity search conditions. In addition, ontological information and suitable index structures are used to improve the search efficiency and effectiveness. XXL is fully implemented as a suite of Java classes and servlets. Experiments in the context of the INEX benchmark demonstrate the efficiency of the XXL search engine and underline its effectiveness for ranked retrieval.     

Teachers’ views on risk factors for problematic school absenteeism in Swedish primary school students

In the present online survey, 158 teachers in regular and special education teaching in grades six to nine were asked to rate the importance of probable reasons for problematic school absenteeism. On average, the teachers estimated that among their students, 19 students had presented with problematic school absenteeism over the last five years. Teachers viewed school absenteeism as a multifactorial problem. Family factors were considered to contribute most and low mood or depression were rated as one of the five most contributing factors. Teachers in special education viewed school factors as more influential than teachers in mainstream education did (t₁₅₆ = ?3.94, p < 0.05). The current findings stress the importance of collaboration between the school, parents and the student to be able to address all factors that may lead to problematic school absenteeism.     

Robuste Indizes für Projection Pursuit

Zusammenfassung.   Die moderne und hoch komplexe Fertigung, z.B. in der Halbleiterindustrie, erfordert für die dabei anfallenden Messdaten der Anlagen- bzw. Prozessparameter multivariate Analysemethoden. Eine dieser m?glichen Analysemethoden ist Projection Pursuit (PP). Dieses Verfahren ist durch geschickte Wahl des so genannten Projektionsindex in der Lage, verschiedenste Datencharakteristika zu detektieren und diese auf anschauliche Weise zu visualisieren. Bei den Projektionsindizes handelt es sich um Funktionen, die eine Projektion auf unterschiedliche Merkmale hin bewerten und dabei jeder Projektion einen Funktionswert zuweisen. Dieser Funktionswert spiegelt die Aussagekraft der Projektion (in Abh?ngigkeit vom verwendeten Index) wider. Die Auswahl bzw. der Aufbau dieser Indizes ist hierbei von entscheidender Bedeutung. Alle hier vorgestellten Indizes zeichnen sich vor allem durch ihren robusten Charakter gegenüber durch Ausrei?er kontaminierte Daten, wie sie in realen Datenszenarien vorkommen, aus. Die durch Anwendung dieser Indizes gewonnenen Einblicke in die komplexe Struktur der Daten erm?glichen es, hochdimensionale Parameterabweichungen und komplexe Zusammenh?nge innerhalb der Daten zu finden. Eingegangen am 11. Februar 2002 / Angenommen am 14. Mai 2002