7,708 research outputs found
Pirate plunder: game-based computational thinking using scratch blocks
Policy makers worldwide argue that children should be taught how technology works, and that the ‘computational thinking’ skills developed through programming are useful in a wider context. This is causing an increased focus on computer science in primary and secondary education.
Block-based programming tools, like Scratch, have become ubiquitous in primary education (5 to 11-years-old) throughout the UK. However, Scratch users often struggle to detect and correct ‘code smells’ (bad programming practices) such as duplicated blocks and large scripts, which can lead to programs that are difficult to understand. These ‘smells’ are caused by a lack of abstraction and decomposition in programs; skills that play a key role in computational thinking. In Scratch, repeats (loops), custom blocks (procedures) and clones (instances) can be used to correct these smells. Yet, custom blocks and clones are rarely taught to children under 11-years-old.
We describe the design of a novel educational block-based programming game, Pirate Plunder, which aims to teach these skills to children aged 9-11. Players use Scratch blocks to navigate around a grid, collect items and interact with obstacles. Blocks are explained in ‘tutorials’; the player then completes a series of ‘challenges’ before attempting the next tutorial. A set of Scratch blocks, including repeats, custom blocks and clones, are introduced in a linear difficulty progression. There are two versions of Pirate Plunder; one that uses a debugging-first approach, where the player is given a program that is incomplete or incorrect, and one where each level begins with an empty program.
The game design has been developed through iterative playtesting. The observations made during this process have influenced key design decisions such as Scratch integration, difficulty progression and reward system. In future, we will evaluate Pirate Plunder against a traditional Scratch curriculum and compare the debugging-first and non-debugging versions in a series of studies
Convex hierarchical testing of interactions
We consider the testing of all pairwise interactions in a two-class problem
with many features. We devise a hierarchical testing framework that considers
an interaction only when one or more of its constituent features has a nonzero
main effect. The test is based on a convex optimization framework that
seamlessly considers main effects and interactions together. We show - both in
simulation and on a genomic data set from the SAPPHIRe study - a potential gain
in power and interpretability over a standard (nonhierarchical) interaction
test.Comment: Published at http://dx.doi.org/10.1214/14-AOAS758 in the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Finite Gap Jacobi Matrices, I. The Isospectral Torus
Let be a finite union of disjoint closed
intervals. In the study of OPRL with measures whose essential support is
, a fundamental role is played by the isospectral torus. In this
paper, we use a covering map formalism to define and study this isospectral
torus. Our goal is to make a coherent presentation of properties and bounds for
this special class as a tool for ourselves and others to study perturbations.
One important result is the expression of Jost functions for the torus in terms
of theta functions.Comment: 68 pages, 4 figure
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