Reading Ontologies

2007-07-03T08:45:00.000-07:00

I stumbled across a great post about the importance of using both cold searching and warm, cuddly, user-generated content.

I totally agree. I love Yahoo! for keeping up its editorially-built directory. I think the Next Big Thing might be a Wiki Directory, with fewer bars to entry than Zeal or ODP - where anyone can submit a site and the problems of spam are solved, somehow.

My favorite quote from the post:

Recently I had a request where the person needed a list of vendors in a particular niche IT area. There was NOTHING available through the traditional sources I'd go to - OneSource, Hoover's, the market research firms or even MarketResearch.com. So what was left?

That's right - directory listings. I found two great directories through Yahoo! and through DMOZ (remember DMOZ? Wow, that seems old), which provided me 85% of the companies I needed to know about, and provided leads to the next 10%.

I've asked the hypothetical question before: could I have just conducted a search for this and found it? No way - my search NEVER would have turned up even 50% of the companies I found using these relatively authoritative directories.

2007-06-01T14:19:00.000-07:00

A new web directory?

The web is all abuzz about Mahalo which is actually quite exciting. It got me to crawl out of the post drought that has overtaken me since getting a non-Web job (I've since come back to the sweet, sweet glory of the web. Oh how I've missed you, Internet.)

Mahalo isn't really a search engine, and I wish it wasn't being called that. It's not a directory, exactly, either. It's supposedly the top 10,000 queries made into coherent result sets by human hands. I'm basically intrigued by the idea, which is exactly what I was involved with at LookSmart for years.

Mahalo presents the results in a neat, organized page. Here's the thing, though: there's too much that's already been sold out on the page. Check out this set for Nike. Under Information, I see Answers.com but not Wikipedia, which provides Answers with most of its meaningful content.

I see a batch of comparison shopping sites, which I know are quite generous with sharing the love with those who link to them. These sites can be really annoying to a searcher who knows where he wants to go. One user was so annoyed that he started a site that runs a custom search which strips out all of the huge price comparison sites from Google results. I spent a lot of time trying to shove a never-ending flood of those sites into the LS directory - they can take over very quickly if you have a zealous sales force who think more sites = gooder salesperson. This assumption is not always true in the search campaign optimization game, as anyone who has mocked an ad reading "Buy ANTIDISESTABLISHMENTARIANISM on eBay" can attest.

Another page shows all of the food searches. Visually, though, there's no differentiation between a category and a results set. That means that when you get all the way to the Dairy category, you see two CHEESE categories that look identical. A little plus sign next to the category with subcategories would be much appreciated here. Once you get to the Dairy category, the presentation of meaning is much clearer, to the point of redundancy. I don't really understand the point of "Everything in Dairy" and "Cheese" as separate groupings at this point, although I suppose eventually they might have a long list of subcategories like they have under food. The category facets under Cheddar feel forced to me. If you're only organizing 9 sites, are three categories needed? And why functional categorization (news & tips, blogs & forums) instead of further subject categories? They've already got disambiguation problems with a cheddar recipe in the Blogs category. Too many mutually non-exclusive categories spoil the taxonomy, I tell you this for free.

Anyway, this is an Alpha release, and therefore these nitpicks are probably not entirely fair. I think that the niche that Mahalo should fill is as a less-corrupt and more open ODP. I've always felt that directories are more useful than people give them credit for, although they are not exactly search engines. They are more search engine symbiotes. A well-built directory can teach a search engine what an apple site looks like as compared to an Apple, Inc. site. The attrition and churn of the Web can take them over very quickly, though, and some of the psychology of directory building (hey, let's add every wikipedia page to every category regardless of the quality of the wikipedia page! Look! A web directory!) can harm the quality and make the directory no better than a slightly informed web search.

But, if they get a chance to continue their experiment, I have some comments about their top level. Why Entertainment and then Music and Television on the same level? What's up with the orphan geographic locations? How come you don't have Austria or California categories? Surely those are top searches? How come when I search for History I end up on the Mozilla page? So many questions.

2006-08-16T22:12:00.000-07:00

I have a joke I like to tell

It's not a very funny joke, but that's okay. Sometimes, if the party is running late and everyone is on their sixth mojito, they will actually laugh at this joke. It's about my idea for a dot-com. A web 1.0 dot-com idea. Sometimes I bring it up randomly. The idea is eHammer. It's an underpants gnome type of idea, and it goes like this:

Step one: Set up website called eHammer: For all your hammer needs
Step two: Mail everyone who asks a free hammer
Step three: ???
Step four: Profit

I was telling my tiresome little story to a person yesterday who is now my new VP of Business Development and Corporate Partnerships. She said, "Step three is to charge everyone for nails."

And I said, hey! We've got a winner!

PS: Hi! Remember me?

2006-03-22T21:05:00.000-08:00

They are shutting down Zeal.

Man. I was a damn lucky dotcommer to not have seen any of my work get totally destroyed like this. Well, up until now. This is the first time they're just going to pull the plug on something I worked on. It was a really great site for a while, if I do say so myself. It could have continued to be good with minimal maintenance. I would have loved to have seen a meta-editor account for some of the more dedicated community members, so that they could have worked in the commercial categories and reclassified paid listings.

I'm really sorry about some of those Expert Zealot questions. You're right, they were pretty hard. Like Oregon DMV trick questions hard.

Semtech2006

2006-03-12T20:40:00.000-08:00

Semtech2006 007
Originally uploaded by ontologista.

I didn't get any good pictures. This poster made me grin a bit, though.

2006-03-08T11:27:00.000-08:00

I've been to a few librariancentric conferences in my time. Every one was a total hen party. Internet Librarian was the closest to gender parity, but there was still a line out the door in the women's room.

This place is a complete sausage-fest. There are maybe two dozen women out of 200 attendees. What's up with that? Seems like ontology and semantics are such a natural extension of librarianship that there should be more of my sisters here. I guess the expression of cataloging concepts using logical notation is scaring us off? I don't know.

On the plus side, I don't have to wait for the bathroom.

2006-03-07T20:52:00.000-08:00

Chris has been writing a bit about tagsology. I love the idea of a paid (or unpaid, depending) ontologist taking care of business on the back end, trying to keep relationships going between concepts. I've been mulling over a couple of problems I can see with formalizing folksonomy in this way.

1. Other than things people are deeply interested in, what is the motivation to tag? I'm here at Semantic Technology and a presenter described a tagging program she instituted at her company. Their content is perfect for tagging, the system was relatively easy to use, yet no one added any tags in six months. Her conclusion is that tagging is not something people do at work, unless it's part of their formal duties. Social search as a whole seems to be focused around passions and hobbies, rather than a large domain of things that need to be retrieved. It'll be really easy to find tags for all 10? of the Doctors from Dr. Who and nothing on the Fed chairmen before Greenspan.

2. People love to be unique. Everyone who has ever dealt with a client knows this. The first thing a client will tell you is why they are a unique flower within their industry, that they do nothing like anyone else, and by the way, have you read their mission statement? People are the same. They don't really want to tag things in such a way that they match each others' tags. Some users will tag cat pictures with the word "puppy" or "Danger!" or, in my case, "Bean" because that's her name. Important or popular documents in a folksonomy get multiple tags, but people need to find them to tag them, and with without the right entry tags, they'll never get found.

2006-03-03T10:05:00.000-08:00

I'm headed to the 2006 Semantic Technology conference in San Jose on Tuesday. If the Fairmont Hotel is suddenly attacked by taxonomist-eating bears, it's possible that controlled data and knowledge management as we know it might change.

See you all there!

2006-02-24T18:47:00.000-08:00

I just joined LibraryThing, which I saw as just another fun internet time-waster that would eventually give me a spreadsheet of all my books. Check out my profile.

Today, the owner announced a radical new feature. Users can merge editions and separate editions. This is what social search is all about. As he says in the post:

Starting three days ago, I announced a trial project to let users determine what books belonged together, the first time anything like this has been attempted. Using simple check boxes, users could go through a favorite author's works, combining and separating editions as necessary.

The response has been startling to say the least: In three days, users have combined 17,000 times, mashing together 42,000 works! Users have spent hours at the task, and debated the nuances in a blog post that now sports 182 comments. Although only a few of these Christmas elves are actual librarians, but most are experts on the authors they labor over. As one wrote on the blog, Isaac Asimov's Nightfall the short story collection, is distinct from Nightfall the novel and from Nightfall One. Do libraries know that? Does Amazon?

Certainly libraries know that. There are countless little cataloging elves spending long hours researching these very topics. Amazon? Well, not so much, I'm sure. I imagine Mr. LibraryThing will be getting some very kind offers for his sweet, sweet data in the near future. That's not what's important, though. These users are interpreting this data in such a way that it will be intelligible to other fans and readers. As someone who worked in libraries in college, separating circulation records from badly-chosen bibliographic records and vice versa, I know this can be a huge job.

As I watch the LibraryThing data grow, I see lots of the typical problems of social sites like this: people use them for their own purposes. That's fine, the more data it gets, the less these unique entries will muddy the waters.

2006-01-12T17:11:00.000-08:00

Creating a New Ontology

I have been shocked to get more than one request for me to update this thing. That must represent more than 100% of my readers. So, shoutouts to CF and KC - this ramble is for you. And CF - it's your turn now!

At my relatively new job, I have been charged with the enviable task of creating a brand-new, from scratch ontology. You might think this would be fairly simple. It should be. I've been working with sub-optimal ontologies both in actual content and in required field structure for so long that I'm feeling quite a bit of option paralysis when faced with the opportunity to do it right for a change. I didn't want to screw it up, so for a while I tried to get more info from the people who are going to use the thing. There was no joy there, they want to see it first before they will give feedback. That's cool. I can work with that.

The ontology tool this company has been working with is an open source tool called Protege, specifically, Protege 2000. I understand that there are new versions out. I haven't yet downloaded it because I'm worried about breaking something. I will probably switch over to the new version as soon as I master this one. The first thing I did when I saw the tool and read the documentation for it was join the mailing list. This list is fun, people from around the world use the software and they are always emailing to ask how you set up a field to do this or that, and sometimes the actual developers will answer. People seem to spend an inordinate amount of time configuring their fields and relationships and then, invariably, they will ask, "are there any pre-existing ontologies for SubjectX I can just plug in?"

This doesn't make much sense to me. On the one hand, I've always referred to pre-existing ontologies to confirm my own sense of right or to ensure that I'm not missing something big. For ontologies that will be used as a public-facing interface, it's important to understand what people are used to seeing. If you plan to change that setup, you'd better have a darn good reason. For instance, maybe you're referring to the Dewey Decimal Classification, and decide that parapsychology and librarianship should not be in the same part of the same category tree. You are probably right, although some of the lame articles I read in library school had worse scholarship than the better parapsychology journals.

On the other hand, everyone needs an ontology for different reasons. A pre-made ontology may be worse than useless. Even adding new clients for an ontology within a company can create a need for customization and simplification.

So this is me, with a list of concepts and their facets in the one hand and a copy of Protege in the other hand. Or rather, laptop. Everywhere else I've worked has had homegrown category/taxonomy/ontology software to work with. And everywhere else I've worked I've been the resident software critic, wondering why it's not good enough to do this or that or the other. Well, after working with Protege, which is as good as it should be considering the multiple ways people use or even define ontology, I apologize to all of the software I've used before. Having something customized for your company's needs is wonderful.

How am I doing at creating this ontology? It's hard to say. I refuse to make the mistake of creating too many fields and relationships. I also don't want to spend too much time entering in data that might not be needed. I currently have four fields and over 300 instances in about 30 classes. I believe it's shaping up nicely, but I haven't shown it to the guy who asked for it yet.

I have a friend who knits. I'm more of a crocheter, myself. This friend will learn a pattern by knitting it until she realizes it's not working. Then she'll unravel and start again. She'll do this as many times as she needs to in order to create a perfect product. This is how I ontologize, and I think that I am very different from the other ontologists whose work I've read. They tend to spend a lot of time planning out where everything is going to go and then have someone else do the data entry. I'd rather gather the data and then just start typing it into the system.

The disadvantage here is that I allow the ontology tool and its limitations shape the scope of what I'm doing. The advantage is that it takes less time in the long run, in my opinion. I also think that I would put The Fear into any unsuspecting ontologist who had to work with me.

2005-11-16T15:35:00.000-08:00

Rookie Category Mistakes

Just because, as George Lakoff points out, every human being thinks in categories, doesn't mean that every human being is good at categorizing for other people. I've come into a few situations where the ontology/category structure/whatever is already in place, and it's my job to fix it or extend it. Every time I train a new person or look over these legacy systems, I see similar mistakes.

For the purposes of this little rant, let's assume that you're building a category structure that will serve as a user interface to data and an organizing system for data management, rather than as a back-end set of rules and axioms that will add meaning to data.

1. Everyone Has an Area of Expertise. This is Dangerous.

The problem with smart people is that they know a lot about how things are Rightly Done and classified. That's fine if you're playing trivial pursuit or working on the Wikipedia.* It's not fine if you're trying to organize something at a level that people who don't know a lot about the topic can access. One very specific mistake that I've run across more than once is the urge people who know linguistics have to organize languages by family. Great idea, right? Sure. It's a great idea, it's correct, it can be used to impart meaning up and down the hierarchy - But it doesn't help someone who doesn't know the first thing about what these families mean. A linguist or student of language knows what these families mean, and might be annoyed to see them arranged alphabetically. However, their needs are subsumed in this case by the person who needs to find their language quickly. I've seen this language-by-family classification in crazy places, like in a drop-down menu for a job application.

There's what's Right and there's what Works. Usually the two are compatible, sometimes they are not. If you're using a taxonomy as a user interface, it has to be usable above all things. If someone who knows nothing about the topic can browse to a simple goal (in the example above: Find the English Language), you've done it right.

This particular mistake leads into the second one:

2. Just because you know about it, doesn't mean it needs to be called out

Let's say you're putting together a category structure for "European Languages" to be used for a travel site that is compiling some commonly used phrases in multiple languages.** You already know that you shouldn't go to crazy with the language family parents, because your users are business travellers who need to find the bathroom, not linguists. Here are some categories you DO NOT need: Romany. Basque. Corsican. Faroese. C'mon, stop showing off.

Time and again I've seen exhaustive, over-granular category structures in specific places while other areas suffer from too-little differentiation. I worked on one taxonomy that had gone to the level of detail of calling out every chip that Intel had ever worked on, but didn't even mention AMD. You need breadth before depth. You need a plan before you dive in. Just because you can build something doesn't mean you should.

*even then, have you ever stumbled across a 46-paragraph cross-referenced article on some bit of pop culture and can't find a single thing about, say, Boise, Idaho? That's a minor weakness of asking a community to work on a project. The project will reflect what the community is interested in, rather than what the community needs more information on.
**I love convoluted examples.

2005-11-10T12:26:00.000-08:00

Truisms about ontologies

What the heck do you use ontologies for? Clay Shirky says they're overrated and useless for organizing content on the Web. This is quite true, at this time you can't use ontology to organize the entire web. (I will probably do a point-by-point reaction to this article at some point. He gets many things right and a few things half-right in distressing ways.) If you can trust content creators and the web community (which, by the way, you can't) you can build an ontology out of their tags and metadata. It still misses those people who don't understand how to create metadata or who can't be bothered to add it to their pages.

Structured data has several practical uses, and things go totally petwang when you try to mix them without acknowledging or understanding that you're mixing them. Here's how I've used ontologies and taxonomies:

A hierarchical taxonomy allows you to present content in an even, logical distribution for people to browse. This is often not accurate but it is understandable and easy to move through.

It can be used to explain semantic meaning to a computer.

It can hold synonyms and relationships between concepts.

It can describe a particular domain and help surface missing content.

One particular friction I've seen pretty much everywhere I've worked is the clash between the need to organize content and the need to have an accurate ontology. Sometimes you have to create classes and categories that are spurious just to present content in a way that is meaningful to a browser and that does not waste their time with needless clicking. For instance: http://dmoz.org/Arts/Performing_Arts/Acting/Actors_and_Actresses/ The letters at the top act like categories, but don't actually impart meaning to the child categories. You can see what letter the person's name starts with just by looking at it. However, if you throw thousands of categories up on a page, you are going to overwhelm your audience. It doesn't make for accurate ontology, but it makes for a good user interface.

2005-11-07T15:52:00.000-08:00

Using the word Ontology in the way that metadata managers and programmers have been using it is pretty controversial. It always annoys people when words that have a specific meaning are co-opted by another group for another purpose. Think of the controversy over "gay". The jury is still out as to whether the expansion of the word "ontology" is a pejoration or a semantic shift

When I got my first real ontology gig, it was, of course, for an up-and-coming dotcom. I helped my boss place an ad in a few places, and because everything was fast and loose and the dotcom hadn't gotten around to hiring an HR department, we used my email address as the return address for prospective candidates. Some grad student from a philosophy department sent me a long rant about how I was personally responsible for the dumbing down of America (which, considering what the Web has done to our attention spans, may have some merit) and that overall we were evil people. He then went on to ask, rhetorically, "What IS an ontologist, anyway?"

I am afraid I emailed him back a rather snotty reply: "An ontologist is a librarian with stock options. Are you applying for the position?" I probably would take that email back if I could. On the other hand, if that's the snottiest I got during the dotcom boom, maybe I'm ahead of most.

Everyone except me has very specific ideas about what "Ontology" is. This guy gets squicky over the use of the definite article with "ontology". He says:

"If you want to really irritate me, refer to a plain taxonomic categorization as "an ontology". It's like calling a case of canned alphabet soup "a literature".

This is part of a general social trend that appropriates the most obvious outward manifestation of something they don't understand and devalues the original concept."

Whoa, hey, back off man. First off, I agree that taxonomy is only a probable component of ontology. I would disagree that taxonomy is "plain." A good taxonomy can be very complex and have multiple relationships within the hierarchy. The hierarchy itself imparts meaning to the concepts. (He goes on to make some very excellent points about the limitations of taxonomy and category structures as a representation of knowledge, so run off and read his post when you get the chance and can overcome his rather condescending writing style.)

Another comparison of the definitions of taxonomy and ontology occurs in the book Ontological Engineering : with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web by Asuncion Gomez-Perez, et al. They say, "Sometimes the notion of ontology is diluted, in the sense that taxonomies are considered full ontologies...the ontology community distinguishes ontologies that are mainly taxonomies from ontologies that model the domain in a deeper way and provide _more restrictions_ on domain semantics. The community calls them lightweight ontologies and heavyweight ontologies respectively. On the one hand, lightweight ontologies [taxonomies] include concepts, concept taxonomies, relationships between concepts, and properties that describe concepts. On the other hand, heavyweight ontologies add axioms and constraints to lightweight ontologies. Axioms and constraints clarify the intended meaning of the terms gathered in the ontology."

I prefer the more relaxed approach of Heavyweight and Lightweight ontologies as opposed to the Philosophy community's stance that the word is being abused and the position of some others that ontologies and taxonomies have nothing to do with each other and anyone who uses the terms interchangeably is automatically an idiot trying to annoy ontological purists.

2005-11-04T10:59:00.000-08:00

The Trouble With Folksonomy

Folksonomies are structured data, usually in the form of tags. These tags are set by the author of the content, and that author is usually an amateur who is just trying to get himself heard, and has a somewhat vague idea of the scope of the broader site. Flickr, Livejournal, Dailykos, and many other sites are currently using folksonomy-type tags. Some of these sites allow any user to register to add additional tags to an entry.

Folksonomies at their best solve one of the biggest problems with metadata: one person or team can't possibly know all the words that might be used to get at a particular piece or type of content. When you open up that pipeline and allow anyone who stops by or contributes to tack on the words he thinks are most relevant, you get so many more entry points to the data. The downside is that when people, particularly people who pride themselves at being outside of the mainstream, are faced with a field in which they are expected to submit something that is relatively standardized and guessable, will try to be unique. Today on Dailykos, kos complained to his users about editorializing in tags: "...the tags are meant to be used as a categorization tool. They're not supposed to be used as a place for editorial comments. ...If you are creating a new tag, make sure it's a legitimate tag ... The success of the tagging feature depends on proper categorization." To some degree, this is true. Deliberate misuse of tagging results in categorization noise that will never be used to return results. I have noticed that many people in online communities get satisfaction from trying new or unique ways to communicate. Livejournal users will put content in their "current music", "current mood", and tag fields that relate to the post but are not related to the way people are likely to browse for the content in the post. Deliberate misspellings, random phrases tangentically related to the topic, and editorial commentary abound.

Is this behavior a problem? It can be, but only if the content is intended to be found and consumed by "outsiders." Many online diarists will use non-standard tags that help them group together their own thoughts within their own journal. These non-standard tags are prevalent on flickr, too. The user striatic from Flickr has an excellent post about how and why to use personal tags, group tags, and public tags.

Impenetrable tagging is not the only issue with folksonomies. When a user uploads a photo, she may just tag it as she sees it: it's a photo of San Francisco, therefore it gets that tag. Many people will miss the obvious entry points and get too general. They will tag a photo with "San Francisco" when the photo is actually of a crowd at the Folsom Street Fair.

These notes on folksonomy are not intended as a condemnation of the idea. I think that a folksonomy that is gently guided by a manager who hooks together similar concepts with a controlled vocabulary (for instance, managing stemming in tags, so that "republican" and "republicans" access the same set of posts) could be a solution to many problems of organization within online communities and content repositories.

2005-11-03T12:48:00.000-08:00

Defining My Terms

`Now you talk like a reasonable child,' said Humpty Dumpty, looking very much pleased. `I meant by "impenetrability" that we've had enough of that subject, and it would be just as well if you'd mention what you mean to do next, as I suppose you don't mean to stop here all the rest of your life.'
`That's a great deal to make one word mean,' Alice said in a thoughtful tone.
`When I make a word do a lot of work like that,' said Humpty Dumpty, `I always pay it extra.'
--Lewis Carroll, Through the Looking Glass

It seems that most language used in describing Internet concepts, especially around ontology and other structured data, are repurposed from other disciplines. (As words get repurposed, so do ideas. The only difference is that we pretend that these are unique and pioneering ideas, rather than acknowledge that we are standing on the shoulders of giants.)

The following are the terms I use a lot, and and how I currently define them to myself. As this experimental self-education continues, I plan to update these definitions as needed.

Ontology - An ontology is a set of concepts and their relationships to each other. The most important aspect of an ontology is those relationships. They give it meaning. Ontologists come in two stripes: those who create ontologies for practical use (that's me!) and those who spend time with the theoretical aspects of ontology. These ontologists wrestle with the problem of defining a semantic relationship to a computer. To do that, your own mind must be very clear on what that relationship is. What is a synonym? What is a related concept, and how does that relationship differ from an alternate parent concept?

Taxonomy - Often used interchangably with Ontology, a taxonomy is a hierarchical category structure in which concepts have one true place. It is more authoritarian and less flexible than an ontology. The Yahoo! directory category structure is a taxonomy by this definition.

Controlled Vocabulary or Thesaurus - (not Roget's thesaurus) These are synonym lists. They point out alternate spellings or words for the same concept. These are of great use in allowing users to perform conceptual searches without exhaustive Boolean logic. Google's misspelling helper is an example of a synonym list, as is the Library of Congress Subject Headings.

Faceted Classification - Every item, idea, or person has multiple attributes that are not mutually exclusive. Things have color and size, for instance. If you gather information (metadata) on these various facets, you can allow searchers to choose the facets they find most important. EBay uses facets in its Product Finders, which can be combined with category browsing. This allows a very targeted search using seller-provided metadata.