Boolean search made easy to understand?

Recently a colleague sent me a link to a little tool called ‘Boolify‘. Boolify is a visual representation of Boolean search and is meant to be an educational tool to help people learn how boolean search terms work together.

Boolean logic (and one of its common applications, Boolean search) is a common ground field between computer scientists and librarians, particularly those who try to teach it. Boolean search is hard to understand for most people, but if users could understand it it would be one of the most powerful tools in their search toolbox (particularly when they are using a search term that has more than one meaning). Good search engine interfaces try and get around it by offering a more ‘natural language’ advanced search interface that lets users do some Boolean searching (see for example the Google advanced search interface below), but the true power and flexibility of real Boolean searching is somewhat lost even in these interfaces.

Screenshot of Google\'s advanced search interface on May 27 2008

Google’s advanced search interface

Now it’s debatable whether the power users lose in an interface like this is even that much of a problem, given that the vast majority of users enter short queries and don’t use advanced search. Arguably there is a chicken-and-egg problem here; users may not use advanced search because (in many cases) it is too hard, meaning they never learn to use it, meaning it is too hard…Whatever came first, I think the answer is that users can usually (at least with Google) find the information they want (or something close enough) without having to get into Boolean logic, and therefore they don’t learn it.

There are some people, though, for who a good grasp of boolean logic is essential. Computer programmers are in this group, as are the librarians to whom people turn when their own searches fail. Potentially students and researchers should have some understanding of Boolean search as well, though I would generally argue for better search interfaces for these groups. So, given the difficulty of teaching Boolean logic (and having taught first year computer science I have first hand experience of this difficulty), anything that would help make it easier would be great.

At first glance, Boolify looks like just such a tool. It would be more awesome if it had a predefined results pool to play with (as well as providing an internet search), so students could see how query reformulation affects what is included in the results pool, but that is pie in the sky, and this thing looks like a good first step. It has puzzle pieces that show how you can interlock different bits of a boolean search, and the horizontal and the vertical can act like brackets in a real search term–the thing at the top is in the innermost brackets, and so on down.

Sadly, though, the promises Boolify makes are not delivered upon. Despite the puzzle pieces providing every promise of being interlockable, queries can only be developed in a linear fashion, and so the pciture below is what happens when you try to develop the query ((libraries OR museums) NOT gallerys) AND ( user experience OR usability). It simply isn’t possible to do, despite the puzzle pieces having every visual and logical affordance needed–you can on develop queries in a line, which means this tool does not represent the full power of Boolean logic. Attempting to make a complex Boolean query using Boolify

Trying to develop a complex Boolean query using Boolify

Usually I would not be so hard on a tool designed to teach something difficult in a novel way, but this tool is a poor teaching aid. It doesn’t allow users to do what it looks like they can do by clicking bits of puzzle in anywhere–thus not showing the true power of Boolean queries, and having a significant usability problem. It also (and I think this is more important) doesn’t let users reformulate queries by moving puzzle pieces around, thus denying a real opportunity to learn how Boolean operators work together by reformulating queries and seeing what happens to the results. I can honestly say that until this tool fulfilled more of its promise, I wouldn’t use it teaching–it is bright and colourful, but it doesn’t bring much more than that to the table.

So, what does everyone else think? Should we leave Boolean logic to the geeks and logicians? Who needs to know Boolean logc, and how should we teach it?


2 Responses to “Boolean search made easy to understand?”

  1. 1 DHC Thursday, May 29, 2008 at 11:44 am

    Hey there,

    Actually, thanks for being hard on the software. I’ll note that part of the issue is that we’re still in beta, and in the forums, are discussing how to fix exactly what you point out.

    But part of the issue is that search Boolean is slightly different than true Boolean logic. It turns out that most major search engines don’t actually support nesting – Google, for instance, which we had to build upon, does *not*.

    This turns the search/query process into the horizontal / vertical procedure currently in place. Translating as best as possible:

    ((libraries OR museums) NOT gallerys) AND ( user experience OR usability)

    into Google syntax is as follows:

    libraries OR museums NOT galleries “user experience” or usability

    which in puzzle format SHOULD be (horizontality & verticality implied by line spacing)

    libraries OR museums
    AND NOT galleries
    AND “user experience” OR usability

    But — I’m going to add your Blog thread to our discussion to continue our progress toward *some* type of solution.

    We’re also developing a “compare” feature, which is in testing form now (to help students compare results between queries). The discussion forum has more info on this as well…

    Finally — thanks again for your comments. Oftentimes, users “accept” an interface as-is, without critique; it’s critique that improves innovation.

    –Dave / PLML

  2. 2 danamckay Thursday, May 29, 2008 at 12:05 pm

    Hi Dave,

    Thanks for you interest and your comments. I’m glad you found my critique useful, and I understand the problems with Google (and other search engines), though (clearly) I hadn’t thought about them when I wrote this post–I come from a computer science background, and I will admit I can have tunnel vision sometimes. I’ll be very interested to see what you come up with in your next release of the software.


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