16,366 research outputs found
Scientific Argumentation as a Foundation for the Design of Inquiry-Based Science Instruction
Despite the attention that inquiry has received in science education research and policy, a coherent means for implementing inquiry in the classroom has been missing [1]. In recent research, scientific argumentation has received increasing attention for its role in science and in science education [2]. In this article, we propose that organizing a unit of instruction around building a scientific argument can bring inquiry practices together in the classroom in a coherent way. We outline a framework for argumentation, focusing on arguments that are central to science—arguments for the best explanation. We then use this framework as the basis for a set of design principles for developing a sequence of inquiry-based learning activities that support students in the construction of a scientific argument. We show that careful analysis of the argument that students are expected to build provides designers with a foundation for selecting resources and designing supports for scientific inquiry. Furthermore, we show that creating multiple opportunities for students to critique and refine their explanations through evidence-based argumentation fosters opportunities for critical thinking, while building science knowledge and knowledge of the nature of science
More on Electric Dipole Moment Constraints on Phases in the Constrained MSSM
We reconsider constraints on \cp-violating phases in the Constrained
Minimal Supersymmetric Standard Model. We include the recent calculations of
Ibrahim and Nath on the chromoelectric and purely gluonic contributions to the
quark electric dipole moment and combine cosmological limits on gaugino masses
with experimental bounds on the neutron (and electron) electric dipole moments.
The constraint on the phase of the Higgs mixing mass , |\thm|, is
dependent on the value of the trilinear mass parameter, , in the model and
on . For values of |A| < 300 \gev at the GUT scale, we find
|\thm|/\pi \la 0.05, while for |A| < 1500 \gev, |\thm|/\pi \la 0.3. Thus,
we find that in principle, large CP violating phases are compatible with the
bounds on the electric dipole moments of the neutron and electron, as well as
remaining compatible with the cosmological upper bound on the relic density of
neutralinos. The other \cp-violating phase \tha is essentially
unconstrained.Comment: 11 pages in LaTeX + 4 postscript figures, uses epsf.sty. Added two
references, clarified figures. Accepted to Physics Letter
Instanton constituents in the O(3) model at finite temperature
It is shown that instantons in the O(3) model at finite temperature consist
of fractional charge constituents and the (topological) properties of the
latter are discussed.Comment: 5 pages, 12 plots in 3 figure
On Multivariate Records from Random Vectors with Independent Components
Let be independent copies of a
random vector with values in and with a
continuous distribution function. The random vector is a
complete record, if each of its components is a record. As we require
to have independent components, crucial results for univariate
records clearly carry over. But there are substantial differences as well:
While there are infinitely many records in case , there occur only
finitely many in the series if . Consequently, there is a terminal
complete record with probability one. We compute the distribution of the random
total number of complete records and investigate the distribution of the
terminal record. For complete records, the sequence of waiting times forms a
Markov chain, but differently from the univariate case, now the state infinity
is an absorbing element of the state space
BGG resolutions via configuration spaces
We study the blow-ups of configuration spaces. These spaces have a structure
of what we call an Orlik-Solomon manifold; it allows us to compute the
intersection cohomology of certain flat connections with logarithmic
singularities using some Aomoto type complexes of logarithmic forms. Using this
construction we realize geometrically the sl_2 Bernstein - Gelfand - Gelfand
resolution as an Aomoto complex.Comment: Latex, 19 page
Some Results on Joint Record Events
Let be independent and identically distributed random
variables on the real line with a joint continuous distribution function .
The stochastic behavior of the sequence of subsequent records is well known.
Alternatively to that, we investigate the stochastic behavior of arbitrary
, under the condition that they are records, without knowing their
orders in the sequence of records. The results are completely different. In
particular it turns out that the distribution of , being a record, is not
affected by the additional knowledge that is a record as well. On the
contrary, the distribution of , being a record, is affected by the
additional knowledge that is a record as well. If has a density, then
the gain of this additional information, measured by the corresponding
Kullback-Leibler distance, is , independent of . We derive the limiting
joint distribution of two records, which is not a bivariate extreme value
distribution. We extend this result to the case of three records. In a special
case we also derive the limiting joint distribution of increments among
records
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