Using published results for the performance of state-of-the-art AI document-vector embeddings and semantic hashing I evaluated a canonical document-vector retrieval system boosted by approximate nearest neighbour search.

The cosine measure is the prevailing similarity function for the document vector model of IR. We discuss a its connection to the intrinsic dimension.

Some unix shell commands to get a plain text list of web sites from publishers which are represented by VG Medien on behalf of the Leistungsschutzrecht für Presseverleger, see Wikipedia entry Ancillary copyright for press publishers.

How many servers does Google need for it's web search? How many pages are crawled and indexed? Starting from Google's 2009 statement that it uses 1 kJ energy per search we estimate that Google used $\approx$ 130.000 servers for its search in 2008. We also speculate that Google only indexes 5% of its crawled pages.

Hierarchical agglomerative clustering (HAC) is a family of different algorithms to perform grouping of data. HAC starts by merging the two data points with smallest distance into a new cluster and finishes with one big cluster describing the data.

How many pages does Microsoft's search engine Bing.com hold in its index? Following the idea of Maurice de Kunder we can roughly estimate the size of Bing's index being 300 million pages.

Initialization of k-means can have a big impact on the performance of the k-means clustering algorithm. Straight forward random initialization can lead to many more iterations compared to a better initialization using kmeans++.