Ask librarians what they think about Wikipedia and you might get some interesting answers. Some will throw up their hands about the laziness of the Google generation and their overdependence on Wikipedia. Some will fatalistically describe the excellent collections at their libraries that are being ignored in favour of shallow internet resources. Some see it as the "competition". And some will tell you it's the greatest thing since sliced bread.
Wikipedia and libraries are in the same business. Both institutions want to make as much knowledge available to as many people as possible, free of charge. Despite these shared aims, the two groups have remained largely distant. Of course, there are librarians who are Wikimedians, and there are libraries that have worked with Wikipedia's GLAM projects. There's Wikipedia Loves Libraries. Wikipedians have developed tools and links to help integrate library resources, but these remain few and underused. Libraries contain vast stores of knowledge, and many want to meet Wikipedia halfway, somehow. How can Wikipedia better bridge the gap to that knowledge?
One barrier to integration is Wikipedia's ad hoc categorization system. In its early days, Wikipedia eschewed the standard organisation schemes in use by libraries, such as the Library of Congress' subject headings. Libraries assign various identifiers to their items; Wikipedia just shoots for a unique title, and maybe a disambiguation term in brackets. The categories come later, and are added (or not added) at the whim of editors.