Eliciting and fostering learners' metacognitive knowledge about language learning in self-directed learning programs: a review of data collection methods and procedures

Són molts els estudis que avui en dia incideixen en la necessitat d’oferir un suport metodològic i psicològic als aprenents que treballen de manera autònoma. L’objectiu d’aquest suport és ajudar-los a desenvolupar les destreses que necessiten per dirigir el seu aprenentatge així com una actitud positiva i una major conscienciació envers aquest aprenentatge. En definitiva, aquests dos tipus de preparació es consideren essencials per ajudar els aprenents a esdevenir més autònoms i més eficients en el seu propi aprenentatge. Malgrat això, si bé és freqüent trobar estudis que exemplifiquen aplicacions del suport metodològic dins els seus programes, principalment en la formació d’estratègies o ajudant els aprenents a desenvolupar un pla de treball, aquest no és el cas quan es tracta de la seva preparació psicològica. Amb rares excepcions, trobem estudis que documentin com s’incideix en les actituds i en les creences dels aprenents, també coneguts com a coneixement metacognitiu (CM), en programes que fomenten l’autonomia en l’aprenentatge. Els objectius d’aquest treball son dos: a) oferir una revisió d’estudis que han utilitzat diferents mitjans per incidir en el CM dels aprenents i b) descriure les febleses i avantatges dels procediments i instruments que utilitzen, tal com han estat valorats en estudis de recerca, ja que ens permetrà establir criteris objectius sobre com i quan utilitzar-los en programes que fomentin l’aprenentatge autodirigit.

Atividade antibacteriana do Aspergillus niger van Tieghem, 1867; pesquisas em 14 amostras da National Collection of Type Cultures (M. R. C.)

1. Pesquisamos a atividade antibacteriana em 14 amostras de Aspergillus niger da National Collection of Type Cultures. 2. Em meio de Raulin e Mosseray, sete amostras apresentaram atividade total, nunca superior a 1:10, contra Staphylococcus aureus nº 553, sendo que as amostras 1.161 e 2.390 permaneceram ativas por mais de 40 dias. 3. A utilização do meio de Czapek-Dox com 5% de "corn-steep" não melhorou os resultados obtidos com o meio de Raulin e Mosseray. 4. No meio de levedo peptonado, todas as amostras apresentaram-se inativas.

Coalition formation in a contest game with three heterogeneous players

We analyze the incentives for cooperation of three players differing in their efficiency of effort in a contest game. We concentrate on the non-cooperative bargaining foundation of coalition formation, and therefore, we adopt a two-stage model. In the first stage, individuals form coalitions following a bargaining protocol similar to the one proposed by Gul (1989). Afterwards, coalitions play the contest game of Esteban and Ray (1999) within the resulting coalition structure of the first stage. We find that the grand coalition forms whenever the distribution of the bargaining power in the coalition formation game is equal to the distribution of the relative efficiency of effort. Finally, we use the case of equal bargaining power for all individuals to show that other types of coalition structures may be observed as well.

A generalized assignment game

The proposed game is a natural extension of the Shapley and Shubik Assignment Game to the case where each seller owns a set of different objets instead of only one indivisible object. We propose definitions of pairwise stability and group stability that are adapted to our framework. Existence of both pairwise and group stable outcomes is proved. We study the structure of the group stable set and we finally prove that the set of group stable payoffs forms a complete lattice with one optimal group stable payoff for each side of the market.

The Adolpho Lutz collection of Tabanidae: (Diptera): I. The described genera and species, condition of the collection, and selection of lectotypes

A study of the Adolpho Lutz Collection of Tabanidae at the Instituto Oswaldo Cruz and of additional Lutz material at the Instituto Butantan in São Paulo is reported. Of the ninety-four species of Tabanidae validly described by Lutz, type material of eighty-four was recognized, either holotypes, allotypes or syntypes. Lectotypes were selected from among syntype series or remaining specimens and all type material was labelled. Of the ten species of which no type material could be found, neotypes were designated in the case of two species, Erephosis nigricans and Erephosis pseudo-aurimaculata. Types of three species, Chrysops ecuadoriensis, Dichelacera salvadorensis and Esenbeckia nigricorpus are believed to have been in Hamburg and destroyed during the last war. Types of two species, Esenbeckia biscutellata and E. dubia, and additional type material of several others are believed to have been in Montevideo. A request for information about them remains unanswered. Types of the remaining three species, Dichelacera intermedia, Dichelacera laceriascia and Esenbeckia distinguenda could not be found, and it is believed that at least the type of the last species was accidentally destroyed. Three specific of subspecific names proposed by Lutz but palaced by others in synonymy have been revalidated, Acanthocera intermedia, Erephosis brevistria and Esenbeckia fenestrata. Generic placement of two names has been changed, Esenbeckia arcuata ricardoae to Proboscoides, and Selasoma giganteum to Stibasoma. Seven specific names proposed by Lutz appear to be synonyms of earlier names, as follows: Bombylopsis juxtaleonina Lutz and Castro, 1936 = B. leonina Lutz, 1909. Bombylopsis pseudoanalis Lutz, 1909 = B. erythronotata (Bigot, 1892). Esenbeckia fuscipennis var. flavescens Lutz, 1909 = Esenbeckia fuscipennis Wied., 1828. Fidena chrysopyga Lutz and Castro, 1936 = F. atra Lutz and Castro, 1936. Laphriomyia longipalpis Lutz and Castro, 1937 = L. mirabilis Lutz, 1911. Stibasoma semiflavum Lutz, 1915 = St. bicolor Bigot, 1892. Tabanus hesperus Lutz, 1912 = Chlorotabanus (Cryptolylus) innotescens (Walker, 1854). Four Lutz names appear to antedate names proposed by others, viz.: Diachlorus angustifrons Kröber, 1930 and D. ochraceus Kröb., 1928 not Macquart, 1850 = Diachlorus fuscistigma Lutz, 1913. Psalidia fairchildi Barretto, 1950 = dicladocera conspicua Lutz and Neiva, 1914. Fidena pseudo-fulvithorax Kröb., 1931 = Erephopsis flavicrinis Lutz, 1909. Esenbeckia lemniscata Enderlein, 1925 = Esenbeckia clari Lutz, 1909. Some comments on Lutz' system of classification are given together with notes on the genotypes and included species of his genera as revaled by his collection and notes.

Does affirmative action reduce effort incentives? A contest game analysis

In this paper a contest game with heterogeneous players is analyzed in which heterogeneity could be the consequence of past discrimination. Based on the normative perception of the heterogeneity there are two policy options to tackle this heterogeneity: either it is ignored and the contestants are treated equally, or affirmative action is implemented which compensates discriminated players. The consequences of these two policy options are analyzed for a simple two-person contest game and it is shown that the frequently criticized trade-off between affirmative action and total effort does not exist: Instead, affirmative action fosters effort incentives. A generalization to the n-person case and to a case with a partially informed contest designer yields the same result if the participation level is similar under each policy.

Inter-group conflict and intra-group punishment in an experimental contest game

We study how conflict in a contest game is influenced by rival parties being groups and by group members being able to punish each other. Our main motivation stems from the analysis of socio-political conflict. The relevant theoretical prediction in our setting is that conflict expenditures are independent of group size and independent of whether punishment is available or not. We find, first, that our results contradict the independence of group-size prediction: conflict expenditures of groups are substantially larger than those of individuals, and both are substantially above equilibrium. Towards the end of the experiment material losses in groups are 257% of the predicted level. There is, however, substantial heterogeneity in the investment behaviour of individual group members. Second, allowing group members to punish each other after individual contributions to the contest effort are revealed leads to even larger conflict expenditures. Now material losses are 869% of the equilibrium level and there is much less heterogeneity in individual group members' investments. These results contrast strongly with those from public goods experiments where punishment enhances efficiency and leads to higher material payoffs.

Handheld-assisted field data collection for occupational risk assessment.

A computerized handheld procedure is presented in this paper. It is intended as a database complementary tool, to enhance prospective risk analysis in the field of occupational health. The Pendragon forms software (version 3.2) has been used to implement acquisition procedures on Personal Digital Assistants (PDAs) and to transfer data to a computer in an MS-Access format. The data acquisition strategy proposed relies on the risk assessment method practiced at the Institute of Occupational Health Sciences (IST). It involves the use of a systematic hazard list and semi-quantitative risk assessment scales. A set of 7 modular forms has been developed to cover the basic need of field audits. Despite the minor drawbacks observed, the results obtained so far show that handhelds are adequate to support field risk assessment and follow-up activities. Further improvements must still be made in order to increase the tool effectiveness and field adequacy.

Affirmative Action Policy and Effort Levels. Sequential-Move Contest Game Argument

In this paper we analyse a simple two-person sequential-move contest game with heterogeneous players. Assuming that the heterogeneity could be the consequence of past discrimination, we study the effects of implementation of affirmative action policy, which tackles this heterogeneity by compensating discriminated players, and compare them with the situation in which the heterogeneity is ignored and the contestants are treated equally. In our analysis we consider different orders of moves. We show that the order of moves of contestants is a very important factor in determination of the effects of the implementation of the affirmative action policy. We also prove that in such cases a significant role is played by the level of the heterogeneity of individuals. In particular, in contrast to the present-in-the-literature predictions, we demonstrate that as a consequence of the interplay of these two factors, the response to the implementation of the affirmative action policy option may be the decrease in the total equilibrium effort level of the contestants in comparison to the unbiased contest game.

How private is private information? The ability to spot deception in an economic game

We provide experimental evidence on the ability to detect deceit in a buyer-seller game with asymmetric information. Sellers have private information about the buyer's valuation of a good and sometimes have incentives to mislead buyers. We examine if buyers can spot deception in face-to-face encounters. We vary (1) whether or not the buyer can interrogate the seller, and (2) the contextual richness of the situation. We find that the buyers' prediction accuracy is above chance levels, and that interrogation and contextual richness are important factors determining the accuracy. These results show that there are circumstances in which part of the information asymmetry is eliminated by people's ability to spot deception.