PowerSet impresses me because of its interface – I can easily see what a particular match is about without leaving the list of search results. Speeding up the typical use cases like this is very important for usability.

Wolfram Alpha impresses me because of the quality of the results. Maybe I’m in the minority thinking this – the press seems to have been giving it mostly negative reviews. Clearly WA is not intended as a Google replacement, but perhaps it was described as being one at some point. Today, being available to the public, it’s something different. It lets me look at data, mostly of the quantitative sort, and make all sorts of semi-interactive charts and comparisons. Here are some searches I liked: earthquakes in Japan, 1 cup of coffee, Tokyo to Osaka. I especially like the interactive earthquake graph.

WA is not without its problems though. Sometimes it’s hard to figure out what kind of queries you can make. I found the above mostly by experimentation. If they exposed more details about their data model and what they knew about each kind of object, maybe this would be easier. Right now I’m wondering why I can do a query like “largest cities” but not “largest cities in mexico”, for instance. I suppose this is mainly a question of maturity both on behalf of the system and of its users, though.

Search engines like PowerSet and WA are indicative of a broader trend towards semantics in computing and internet usage. While the semantic web isn’t here yet in the sense that we don’t have a semantic web browser or a unified way of querying the internet, clearly services that are based very heavily on semantic models are becoming mainstream. More on the impact of this in a future post.

One of the most important problems in software engineering is reducing the impact of change. To this end, recently methods such as inversion of control (dependency injection) have become popular, in order to reduce the coupling to concrete interfaces. However, even with these schemes, there is still a dependency on specific names and abstract interfaces.  My project aims to investigate the possible use of semantic methods to address this problem. In essence, I want to allow developers to use semantic interfaces rather than syntactic ones to describe and access their components. 

Specifically, I am investigating techniques commonly used in the context of Semantic Web Services, such as ontologies and semantic/syntactic mediation, and their applicability to this problem. 

We may regard services as being somewhat large scale components. However, I am interested in applying these methods not just for large scale services distributed across the web, but also for small and numerous software components running in a single process. In such a setting, performance and scalability are important issues to investigate, in addition to the usual problems of reliability, correctness of composition, etc.