1,721,230 research outputs found
Observations on the Life History ofEnema pan(F.) (Coleoptera: Scarabaeidae: Dynastinae) and Its Association with Bamboo,GuaduaKunth (Poaceae: Bambusoideae), in Southwestern Amazonia
No full textJacobs, Jennifer M., May, Rudolf von, Ratcliffe, Brett C. (2012): Observations on the Life History ofEnema pan(F.) (Coleoptera: Scarabaeidae: Dynastinae) and Its Association with Bamboo,GuaduaKunth (Poaceae: Bambusoideae), in Southwestern Amazonia. The Coleopterists Bulletin 66 (3): 253-260, DOI: 10.1649/072.066.0312, URL: http://dx.doi.org/10.1649/072.066.031
Undergraduates' (mis) understanding of percentages
No full textChildren and adults alike continue to have difficulty with rational numbers, and, as shown in this study, percentages. Adult undergraduate students (N = 27) completed an untimed open-ended study that had a pretest-training-posttest design. Questions in the pretest and posttest focused on percent increases and decreases (e.g., The price x was increased by 20%). They were formatted in one of three representations: decimal, fraction, or bar graph. Subjects were randomly assigned to one of two training groups (decimal or fraction) that involved guiding them through the conceptual and procedural component processes that contribute to the solutions to problems within a given representation (i.e., decimal or fraction). Additional questions were asked in the pretest and posttest pertaining to successive percent increases and decreases. Overall, students performed best on bar graph representations. While decimal training had no effect on performance, fraction training improved performance from pretest to posttest in every category (decimal, fraction and bar graph). Students who had not yet taken Calculus were shown to have benefited more from the fraction training than those students who had taken that course. In contrast, prior math experience did not seem to have any effect on those questions dealing with two percent changes within one problem; less than 25% of these types of problems were answered correctly by the undergraduate students.M.S.Includes abstractIncludes bibliographical referencesby Jennifer A. Jacob
Percents are not natural numbers
No full textAdults are prone to treating percents, one representational format of rational numbers, as novel cases of natural number. This suggests that percent values are not differentiated from natural numbers; a conceptual shift from the natural numbers to the rational numbers has not yet occurred. This is most surprising, considering people are inundated with rational numbers all around them, from the “% Daily Values” on nutrition labels to sales and discounts in stores to the constant ups and downs of gas prices. From an early age, humans have a rather robust concept of natural number, but this earlier knowledge seems to act as a barrier to future learning of rational number. While participants performed better on one-statement problems with a single percent, they ignored the principles of rational number when presented with two-statement percent problems. For example, using rational numbers involves dropping the successor principle, a principle that applies to the natural numbers. Problems presented algebraically gave participants great difficulty, though performance improved when subjects were able to replace the variable y with a natural number (100). When using a numerical hint (substituting in a value during a training phase), participants still did not improve their performance on algebra problems in posttest. Error analyses revealed a strong tendency for students to interpret the problems as novel examples of natural number problems. This research discusses the failure to understand percents in light of overuse or failure to apply the natural number successor principle, division, false cognates, and the absence of knowledge that relates multiple rational number representations to a common underlying knowledge structure. The amount of previous math experience is also correlated with the ease of moving between natural number and rational number concepts.Ph. D.Includes bibliographical referencesIncludes vitaby Jennifer A. Jacob
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Fig. 2 in Observations on the Life History ofEnema pan(F.) (Coleoptera: Scarabaeidae: Dynastinae) and Its Association with Bamboo,GuaduaKunth (Poaceae: Bambusoideae), in Southwestern Amazonia
No full textFig. 2. Photographs illustrating the mound and burrow of Enema pan at the base of a bamboo stem. a) The mound at the base of a bamboo stem, b) Excavation of the mound, c) An excavated mound with a Swiss army knife (9 cm length) for perspective, d) The same excavated mound with pieces of pink flagging to illustrate the path of the underground portion of the burrow.Published as part of <i>Jacobs, Jennifer M., May, Rudolf von & Ratcliffe, Brett C., 2012, Observations on the Life History ofEnema pan(F.) (Coleoptera: Scarabaeidae: Dynastinae) and Its Association with Bamboo,GuaduaKunth (Poaceae: Bambusoideae), in Southwestern Amazonia, pp. 253-260 in The Coleopterists Bulletin 66 (3)</i> on page 257, DOI: 10.1649/072.066.0312, <a href="http://zenodo.org/record/10108111">http://zenodo.org/record/10108111</a>
Fig. 3. Enema pan adult and larva. a in Observations on the Life History ofEnema pan(F.) (Coleoptera: Scarabaeidae: Dynastinae) and Its Association with Bamboo,GuaduaKunth (Poaceae: Bambusoideae), in Southwestern Amazonia
No full textFig. 3. Enema pan adult and larva. a) Male inside mound, b) Male perching on top of mound, c) Larva (inset) collected inside burrow along with wet, crushed leaves and sticks (main image), d) Male near burrow after excavation of burrow; this individual was found at the end of the main tunnel after excavation.Published as part of <i>Jacobs, Jennifer M., May, Rudolf von & Ratcliffe, Brett C., 2012, Observations on the Life History ofEnema pan(F.) (Coleoptera: Scarabaeidae: Dynastinae) and Its Association with Bamboo,GuaduaKunth (Poaceae: Bambusoideae), in Southwestern Amazonia, pp. 253-260 in The Coleopterists Bulletin 66 (3)</i> on page 258, DOI: 10.1649/072.066.0312, <a href="http://zenodo.org/record/10108111">http://zenodo.org/record/10108111</a>
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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