Acquisition and Use of Mental Operators: Effects of Type of Practice

2002 ◽  
Vol 49 (2) ◽  
pp. 141-152 ◽  
Author(s):  
Burkhard Müller ◽  
Jürgen Gehrke
Keyword(s):  
Mental Models ◽  
Test Performance ◽  
Physical World ◽  
Test Phase ◽  
Acquisition Phase ◽  
Practice Test ◽  
Subsequent Test ◽  
Use Of Knowledge

Abstract. Planning interactions with the physical world requires knowledge about operations; in short, mental operators. Abstractness of content and directionality of access are two important properties to characterize the representational units of this kind of knowledge. Combining these properties allows four classes of knowledge units to be distinguished that can be found in the literature: (a) rules, (b) mental models or schemata, (c) instances, and (d) episodes or chunks. The influence of practicing alphabet-arithmetic operators in a prognostic, diagnostic, or retrognostic way (A + 2 = ?, A? = C, or ? + 2 = C, respectively) on the use of that knowledge in a subsequent test was used to assess the importance of these dimensions. At the beginning, the retrognostic use of knowledge was worse than the prognostic use, although identical operations were involved (A + 2 = ? vs. ? - 2 = A). This disadvantage was reduced with increased practice. Test performance was best if the task and the letter pairs were the same as in the acquisition phase. Overall, the findings support theories proposing multiple representational units of mental operators. The disadvantage for the retrognosis task was recovered in the test phase, and may be evidence for the importance of the order of events independent of the order of experience.

scholarly journals The Relationship between Socio-Economic Status, General Language Learning Outcome, and Beliefs about Language Learning

2016 ◽  
Vol 9 (2) ◽  
pp. 89
Author(s):  
Mohsen Ghasemi Ariani ◽  
Narjes Ghafournia
Keyword(s):  
Socioeconomic Status ◽  
Language Learning ◽  
Language Proficiency ◽  
Measurement Errors ◽  
Economic Status ◽  
Learning Outcome ◽  
Practice Test ◽  
Postgraduate Students ◽  
Beliefs About Language Learning ◽  
Iranian Students

<p class="apa">The objective of this study is to explore the probable relationship between Iranian students’ socioeconomic status, general language learning outcome, and their beliefs about language learning. To this end, 350 postgraduate students, doing English for specific courses at Islamic Azad University of Neyshabur participated in this study. They were grouped in terms of their socioeconomic status. They answered a questionnaire in which they indicated their beliefs about language learning in different contexts of language use. Besides, a general language test of proficiency (a Practice test of a TOEFL Test) was administered to all the participants to homogenize them in terms of general language proficiency or general language learning outcome. The quantitative data were subjected to a set of parametric statistical analyses, including descriptive statistics and factor analysis. The findings manifested a positive relationship between the students’ economic status and general language learning outcome. Besides, the findings manifested a significant relationship between the participants’ language learning outcome and their beliefs about language learning. The findings suggest if language instructors are equipped with the necessary information to assist language learners in coping with their negative beliefs, the process of language learning is not only accelerated, but also probable measurement errors may decrease.</p>

scholarly journals Field Experience of Antibody Testing against Mycoplasma bovis in Adult Cows in Commercial Danish Dairy Cattle Herds

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 637 ◽  
Author(s):  
Mette Bisgaard Petersen ◽  
Lars Pedersen ◽  
Lone Møller Pedersen ◽  
Liza Rosenbaum Nielsen
Keyword(s):  
Best Practice ◽  
Field Conditions ◽  
Mycoplasma Bovis ◽  
Antibody Testing ◽  
Serum Samples ◽  
Practice Test ◽  
Milk Samples ◽  
Cattle Herds ◽  
Paired Serum ◽  
Danish Dairy

Mycoplasma bovis in cattle is difficult to diagnose. Recently, the ID screen® mycoplasma bovis indirect ELISA (ID screen) was commercially released by IDVet. The objectives of this study were to: (1) gain and share experience of using the ID screen in adult dairy cows under field conditions; (2) determine the correlation between antibody levels in milk and serum and (3) compare the ID screen results with those of the Bio K 302 (BioX 302) ELISA from BioX Diagnostics. Paired serum and milk samples were collected from 270 cows from 12 Danish dairy herds with three categories of M. bovis disease history. The ID screen tested nearly all cows positive in all, but the three non-infected herds, while the BioX 302 tested very few cows positive. The ID screen is therefore a much more sensitive test than the BioX 302. However, cows in five exposed herds without signs of ongoing infection and two herds with no history of M. bovis infection also tested ID screen positive. Therefore, the performance and interpretation of the test must be investigated under field conditions in best practice test evaluation setups. A concordance correlation coefficient of 0.66 (95% CI: 0.59–0.72) between the ID screen serum and milk results indicates that milk samples can replace serum samples for the ID screen diagnosis of M. bovis in adult cows.

Practice Test # 2: Difficulty Level-Moderate

2012 ◽  
pp. 77-151
Author(s):  
Andrzej Moniuszko ◽  
Adam Sciuk
Keyword(s):  
Difficulty Level ◽  
Practice Test
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