As looking at the wikigalaxy its looks really cool but it would be nice for users to be able to create custom galaxies, galaxies with set limits, meaning that show only those pages that fit a specific category. Its almost the same idea like google earth, but just like article mentioned it has only 100,000 articles so far i think in future wikigalaxy will be a useful tool to have it.

Article on types of sources is really clear and easy to follow, now at least i can tell the difference between primary, secondary and tertiary sources. I feel like secondary and tertiary sources are related to one another.