Knowing more about things you care less about : cross-sectional analysis of the opposing trend and interplay between conceptual understanding and interest in secondary school chemistry

The development of students' interest in school science activities, their understanding of central chemical concepts, and the interplay between both constructs across Grades 5–11 were analyzed in a cross‐sectional paper‐and‐pencil study (N = 2,510, mean age 11–17 years). Previous empirical findings indicate that students' knowledge increases over the time of secondary school while students' interest, especially in natural science subjects, tends to decrease. Concomitantly, there is evidence for an increase in the positive coupling between interest and knowledge across time. However, previous studies mainly rely on rather global measures, for example, school grades or general subject‐related interest, and focus on science as an integrated subject instead of specific disciplines, for example, chemistry. For this article, more proximal and differentiated measures for students' understanding of three chemical concepts (Chemical Reaction, Energy, Matter) and interest in seven dimensions of school science activities according to the RIASEC + N model (Realistic, Investigative, Artistic, Social, Enterprising, Conventional, and Networking; cf. Dierks, Höffler, & Parchmann, 2014) were applied. The results are in line with previous research indicating a general increase in conceptual understanding and a decline in students' interest for all school science activities. However, the interplay between conceptual understanding and interest differs across the seven dimensions. Interest in activities which are likely to promote cognitive activation (investigative, networking) or involving the communication of knowledge (social, enterprising, and networking) are increasingly connected to conceptual understanding, especially in upper secondary grades. Interest in guided hands‐on activities (realistic) which are typical in secondary science teaching, however, shows only small positive correlations to students' conceptual understanding across all grades. Hence, in upper‐secondary school, investigative, social, enterprising, and networking activities seem to provide opportunities to benefit most from the interrelation between students' interests and their understanding

Morphologic Variants of Posterolateral Tibial Plateau Impaction Fractures in the Setting of Primary Anterior Cruciate Ligament Tear

Background: Impaction fractures of the posterolateral tibial plateau commonly occur in the setting of anterior cruciate ligament (ACL) tears, with considerable variability found in fracture size and morphologic features. Purpose: The primary objective was to characterize different morphologic variants of posterolateral tibial plateau impaction fractures. The secondary objective was to investigate the association between these impaction fracture variants and concomitant meniscal and ligamentous injuries. Study Design: Cross-sectional study; Level of evidence 3. Methods: Patients treated for primary ACL tears and having magnetic resonance imaging available were included in this study, and magnetic resonance images were reviewed with denotation of displaced posterolateral tibial impaction fractures. A classification system was created based on morphologic variants of impaction fractures; associations were evaluated through use of independent chi-square testing. Results: There were 825 knees meeting the inclusion criteria, with displaced posterolateral tibial plateau impaction fractures present in 407 knees (49.3%). We observed 3 distinct morphologic variants of lateral tibial plateau impaction fractures: (I) posterior cortical buckle not involving the articular surface; (II) posterior impaction fracture involving the articular surface, with subtypes based on (A) tibial plateau depth bone loss 10%; and (III) displaced osteochondral fragment, with subtypes for (A) shear or (B) depressed fragment. Type IIIA impaction fractures were associated with an increased incidence of lateral meniscus posterior root tears (33.3% vs 12.4%; P = .009) and an increased incidence of lateral meniscal tears (83.3% vs 56.7%; P = .024) compared with all knees without type IIIA impaction fracture. An increased incidence of medial collateral ligament (MCL) tears was noted in patients with type IIIA impaction fractures compared with those who had no fracture or had another fracture type (61.1% vs 20.1%; P < .001). Type IIIB impaction fractures were associated with an increased incidence of lateral meniscal tears (80.0% vs 56.2%; P = .005). Conclusion: A high prevalence of displaced posterolateral tibial plateau impaction fractures occur in the setting of ACL tears, and they can be classified into distinct morphologic subtypes. Posterolateral tibial plateau impaction fractures with displaced depressed or shear fragments were both associated with an increased incidence of lateral meniscal tears, whereas impaction fractures with a shear fragment were associated with an increased incidence of lateral meniscus posterior root tears and MCL tears

Online signal extraction by robust linear regression

Robust filtering, least median of squares, least trimmed squares, repeated median, deepest regression, breakdown point,