We explore modeling problem solving and design using state-space-search methodology by engaging in the design of an educational game. We also explore how online communication tools (OCTs) could be used to support collaborative design using two online tools: 1) CoSolve, a collaborative problem-solving environment we developed, and 2) INFACT, a discussion forum that we built for use in education. We used these tools to design GoAtom, a chemistry game. Using our game design experience as an example, we present a method for modeling design processes using state-space-search, and reflect on our use of OCTs.

Users of decision support system typically submit batches of range-sum queries simultaneously rather than issuing individual, unrelated queries. We propose a wavelet based technique that exploits T/O sharing across a query batch to evaluate the set of queries progressively and efficiently. The challenge is that now controlling the structure of errors across query results becomes more critical than minimizing error per individual query. Consequently, we define a class of structural error penalty functions and show how they are controlled by our technique Experiments demonstrate that our technique is efficient as an exact algorithm, and the progressive estimates are accurate, even after less than one I/O per query.