Modeling a century of citation distributions

The prevalence of uncited papers or of highly cited papers, with respect to the bulk of publications, provides important clues as to the dynamics of scientific research. Using 25 million papers and 600 million references from the Web of Science over the 1900–2006 period, this paper proposes a simple model based on a random selection process to explain the “uncitedness” phenomenon and its decline over the years. We show that the proportion of cited papers is a function of (1) the number of articles available (the competing papers), (2) the number of citing papers and (3) the number of references they contain. Using uncitedness as a departure point, we demonstrate the utility of the stretched-exponential function and a form of the Tsallis q-exponential function to fit complete citation distributions over the 20th century. As opposed to simple power-law fits, for instance, both these approaches are shown to be empirically well-grounded and robust enough to better understand citation dynamics at the aggregate level. On the basis of these models, we provide quantitative evidence and provisional explanations for an important shift in citation practices around 1960. We also propose a revision of the “citation classic” category as a set of articles which is clearly distinguishable from the rest of the field.     

Training myths: False beliefs that limit the efficiency and effectiveness of training solutions,part 1

This article questions commonly held beliefs about training as a component of performance improvement solutions. Rather than being based on theoretical and empirical support, many beliefs about training are based on little more than myth. Part 1 of this article presents myths about the relationship of training and performance and myths about determining training content. Training fails when the performance problem is caused by something other than a lack of knowledge or skill. And it is compromised when we fail to include only the essential content.     

The Influence of Risk Factors on Preschoolers’ Spanish Vocabulary Development in the Context of Spanish Instruction

Research Findings: This longitudinal study investigated the Spanish vocabulary development of dual-language-learning (DLL) children (N = 150) from Spanish-speaking, low-income, predominantly immigrant homes who were enrolled in a state-funded preschool program that provided instruction in Spanish. Children’s Spanish vocabulary trajectories were examined, as were patterns of co-occurring risk. In addition, the relation of individual and cumulative risk factors at preschool entry on Spanish vocabulary development was explored. Findings reveal that, on average, children’s receptive Spanish vocabulary skills, which started below age-level norms at the beginning of the preschool year, grew to surpass age-level norms by the end of the year. These gains were made despite children facing, on average, eight risk factors. The investigation of patterns of co-occurring risk and the effect of individual risk factors on Spanish vocabulary outcomes reveal that some social risk factors, such as having an unemployed parent, might function as a protective factor in this population. Practice or Policy: This study paves the way for future work in determining the role of native-language instruction for supporting language growth among DLL children. In addition, it expands the research literature on the nature and influence of social and economic risks in this population of children.     

A Study of General Education Astronomy Students’ Understandings of Cosmology. Part V. The Effects of a New Suite of Cosmology Lecture-Tutorials on Students’ Conceptual Knowledge

This is the final paper in a five-paper series describing our national study of the teaching and learning of cosmology in general education astronomy college-level courses. A significant portion of this work was dedicated to the development of five new Lecture-Tutorials that focus on addressing the conceptual and reasoning difficulties that our research shows students have with frequently taught cosmology topics, such as the expansion of the universe, the Big Bang, and dark matter. We conducted a systematic investigation of the implementation of these new Lecture-Tutorials and resulting learning gains in order to test the efficacy of these new Lecture-Tutorials. Our investigation included classroom observations, results from pre–post testing using four conceptual cosmology surveys, and comparisons between classes in terms of the class time spent on cosmology topics and other instructional strategies used to teach cosmology. We used this combination of qualitative and quantitative research results to evaluate the conceptual understandings of students who used the new cosmology Lecture-Tutorials compared to those students who did not. The analysis of our data shows that, in many cases, classrooms that used the cosmology Lecture-Tutorials saw a greater increase in their students’ conceptual cosmology knowledge compared to classrooms that did not use the cosmology Lecture-Tutorials. However, our results also indicate how instructors implement the Lecture-Tutorials into their classrooms strongly influences their students’ learning gains.     

Stimulus modality and short-term memory in rats

Two experimental paradigms are presented aimed at determining the retention of auditory and visual information over brief delay intervals. First, a conditional delayed matching-to-sample procedure was used in which rats were required to symbolically match the modality of the sample stimulus with one of two comparison stimuli. In the second experiment, subjects were trained and tested using a Konorski-type procedure. Despite the conceptual and procedural differences between the two procedures, subjects in both experiments showed steeper forgetting functions for visual events than for auditory events, while performance levels at 0-sec delay intervals were equivalent for both stimuli. These results, when taken together with related research conducted with pigeons, suggest that content of memory may have important influences on the short-term retention abilities of animal subjects.     

Notes on Contributors

Concepts adapted from structuration theory are employed to analyse how a disjunction has been created and sustained between the form taken by annual development plans for schools and a more flexible approach to planning that appears, from small‐scale research, to be effective at school level. The interest of LEAs and central government in a high degree of external control over school development is interpreted as contradictory to the interest at school level in maintaining a high degree of control over internal development. It is argued that action according to these contradictory interests has not led to conflict because completion of the plan has been kept largely separate from ongoing strategic planning at school level. The concepts employed in this analysis are defined, features of LEA development plans for schools are discussed, research evidence on development planning is summarized, and unintended consequences of development plans as a form of bureaucratic control are suggested.     

Individual differences in infants' information processing: reliability, stability, and prediction

A group of 46 full-term and 54 high-risk preterm (less than 1,500 grams birthweight) infants were tested at 6, 7, and/or 8 months of age (corrected age for preterms) on a battery of problems assessing visual recognition memory and tactual-visual cross-modal transfer. At all 3 ages, scores obtained on aggregates of 6-11 problems in the battery significantly predicted 3-year Stanford-Binet IQ: correlations ranged from r = .37 to r = .63, and clustered between r = .50 and r = .60. When aggregates from 2 or 3 ages were used as predictors, multiple correlations were as high as R = .60 and R = .70. Cutoffs for predicting children at risk for mental retardation (IQ less than 70) or cognitive delay (IQ less than 85) showed reasonable sensitivity and specificity, although low scores were poor at detecting IQs less than 70. The internal consistency of composites, indexed by alpha coefficients, was unexpectedly low, primarily because the problems shared little variance. However, stability coefficients between assessments as much as 1 and 2 months apart were moderate in magnitude, ranging from r = .30 to r = .50. Considering the high degree of predictive validity, the stability figures appear to be better estimates of reliability for these measures than are indices of internal consistency. The relations reported here were similar for both full-terms and preterms.     

Teaching an Innocence Case Review Course to Undergraduate Students

After two years of experience in overseeing groups of undergraduate and graduate criminal justice students in an Innocence Case Review course at the University of Central Missouri (UCM), the authors reviewed the structure of the course and the attitudes of the participating students. An examination of Innocence Case Review current procedures in undergraduate institutions and law schools provides background for course design. This article summarizes the findings of the students’ experiences, reactions, and attitudes of their yearlong case screening efforts, and to the criminal justice system in general. The first part of this article examines the literature on innocence case review classes at both undergraduate institutions and law schools exploring different learning styles and strategies inherent in this type of class. It also explores the skills necessary for case review, and the skills students can take to other classes and professions. The second part reviews the structure of our courses as initially created and implemented for the last two academic years at UCM and the modifications the instructors felt necessary for the future. The third part examines the survey conducted by the UCM’s Innocence Case Review class, including student suggestions for class improvements and advice to students selected for the new academic year. The benefits and abilities gained by the students through this course become apparent. The fourth part discusses and evaluates the current class structure and reforms suggested by the UCM students, the professors’ experience, and as indicated by other universities. The conclusion reviews findings gathered from the current course as well as examining other universities’ courses, and the value students experience from participating in this experiential or engaged learning.     

Removal of mercury from solutions of mercuric nitrate by mercuric sulfide

The removal of mercury from dilute solutions of mercuric nitrate by mercuric sulfide is indicative of an adsorption process. The relation of log $\text{x}\text{m}$ vs. log C shows that the Freundlich adsorption isotherm exists.At higher concentrations of mercuric nitrate a reaction takes place with the mercuric sulfide forming a compound of the possible formula 2HgS·Hg(NO₃)₂ mercuric nitratodisulfide.