One of my favorite teaching tools is a box of Legos. I’ve built several lessons around Legos, and it is a guaranteed way to get my upper school students excited about a library session. The lesson I’m sharing here is one I use with 9th graders. The objective is to have students understand what a controlled vocabulary is, how it works in the context of searching, and how that applies to LOC Subject Headings and subject searches.

The set-up: I pre-sort my Legos into standard bricks and irregular pieces, providing a pile of standard bricks, randomly, to each student (or small groups, depending on the student:Lego ratio). I tell them we are building a database of Legos and get some volunteer input to get a definition of what a database is. I then give students about 4 minutes to decide with a partner/small group how they will categorize their Legos so we can search our database to find the right bricks.

Depending on the space that I have, students may write their categories on the board as they discuss, or share them out after and I will write. Typically they offer categories like color, shape, size. For each, I press a bit further and we get lists like:

• Color
  • Red, green, blue, white, yellow
• Shape
  • Square, rectangle
• Size
  • Number of studs (yes, that’s what the bumps on Legos are called)
  • Stud dimensions (1×2, 2×2, 2×4, etc.) 
  • Short or tall (in Lego lingo this would be plate or brick)

Next, we try “searching” our database. I’ll call out a search and the students will push forward their “results” on their desks. I start easy with things like “red” or “square.” I point out how they can combine things “red AND 2×2” and bam, we get the brick we want. 

But, as librarians we know it’s not so easy to search and get what you want, so I point out that there are, in fact, three different shades of blue in my Lego set and that I may do a search for “turquoise,” which based on what we established as a class, is not an option: zero results. This creates the opportunity to discuss the challenges of controlled vocabularies for searchers–if I don’t know the language used for the colors, my search for turquoise will leave me thinking there are no results for me, when there are a lot of turquoise Legos, they are just called blue. So, do we keep it broad and say I should just search for blue and then I have to sort through all the blue results to find the ones that are turquoise, or do we want our Lego database to specify what our three different shades of blue should be called? And, will that alway help? What if I call the lightest shade turquoise but they call it “light blue” or “sky blue”? And, how would I know what words to use? When we work through it like this, students catch on quickly.  At this point, I let them build a creation from the bricks they have as we plow forward. 

New information gets created all the time, so our database expands– I give them a few more Legos from the bits set aside earlier and we upload this new data into our system. We quickly hit complications. How, for example, am I supposed to search for a wheel when our data structure doesn’t have a way to do that–wheels are not square or rectangular and they don’t have studs. Or how would we find a sloped piece? Or other irregular pieces? My goal here is for them to see that, while imperfect, adding more specific categories titles for our blue issue seemed like a fairly simple fix. If we try to come up with names and categories for all the irregular shapes the vocabulary gets unwieldy and it becomes even more confusing to know what to call things. How we chose to include information, label it, and organize it, impacts how it is used. 

Now I introduce LOC Subject Headings and how that language can be obscure, biased, and difficult to find as a novice searcher. But also, knowing how information is labeled and organized helps you know how you can search for it, as well as how some questions may not be readily answered by the way information is organized. We do exploratory searching in our catalog (we use AccessIt) so I can show them how to find the Subject Headings of results of their searches, that those are clickable links that redo a search, and how to backtrack to the stem if the subject is too specific.

The best part is I get to do a lesson on searching that engages my students without relying on walking them through searches projected on the board and connects to the ACRL Frame, Searching as Strategic Exploration through the knowledge practices: understand how information systems are organized in order to access relevant information; and, use different types of searching language (e.g., controlled vocabulary, keywords, natural language) appropriately.