Here's a post that discusses a word that happens to represent an important leap in abstract thinking that helps us to understand how distributed software elements communicate and establish logical connections. Meta. Actually it's more a prefix than a word. A full appreciation of the subject is beyond the scope of this course. But a basic understanding of the role of metadata and even metalanguages will take you far in your understanding of the power and elegance of new software.
First let's start off with a discussion about form vs. content. We talked about this a bit when we introduced the World Wide Web. Form refers to the way something is presented or used. Form carries, conveys, and communicates. Content on the other hand is exactly that which is being carried, conveyed, or communicated. This is a simple but very powerful distinction. Take a creative work like Anne of Green Gables for instance. Anne and her story might be considered content. What's the form of Anne of Green Gables? Originally it was a bound novel written in elegant English prose by LM Montgomery. But wait there are other forms of AOGG. There was a play and a movie for instance. Now there's a cartoon series. And of course tonnes of merchandise too. This illustrates how the content of Anne can be presented and used in different forms.
Form can take on many dimensions. The style in which Anne was written is part of it's original form. So is the typeface, the chapter outline, the illustrations, and the bounded hard copy of the actual book. Even the word "novel" illustrates a dimension of the original form of AOGG.
Now let's turn the discussion back to metadata.
In computing metadata refers to data about data.
A classic illustration of this concept uses our common library card catalog system --the information provided by a library catalog card and its relationship to books. You see, books represent the content of a library. Books are the chief items which a library archives and the objects which we usually seek when we go to the library. But, typically, there are thousands and thousands of books in the library - complex books. If we had no system to classify and organize these books we would waste a lot of time going through these stacks of books to find what we're looking for. We might confuse books of a similar nature. We might even lose track of those books, and so on. A system of classifying and organizing books was created to make the process of managing this massive collection of complex objects easier and more standard. Catalog cards are used to archive and index data about books which then present library users with a simpler, faster way of finding a specific book and pinpointing its location in the vast stacks. The information which describes a book and its place in this system of classification and organization is its metadata. What other classic examples of systems that rely on metadata?
Returning to the world of computing now, metadata or data about data is an essential aspect of distributed computing. Because the components of a software system and the data it uses may be distributed over a network it is important that, say, documents and data, even software components themselves, come with their own metadata-- like a "user manual" --that can be read by another application to prepare for, interpret, and apply instructions which are necessary to use it. This metadata, like a library's card catalog isn't the content but the indexed system of classification and organization that refers to the content . So, by referring to data about itself, documents, data, and software compoents tell others what it is, what state it's in, and even how it can be used. This is how distributed systems make logical connections across applicaitons and how they keep track of decisions and events.
Metadata is a description of objects, documents or services which may contain data about their form and content. It may also be used as a guide to operations which may be performed. Metadata may be stored as part of the resources themselves (embedded) or kept separately from them (repository).
Metadata systems are found not only in libraries but also in museums, archives, in scientific communities, and all over the Internet.
If you are sharp you will notice that metadata describes aspects of form and content. This is important!
Why Is Metadata Important?
Metadata is critical to preserving the usefulness of data over time. For instance, metadata captures important information on how the data were collected and/or processed so that future users of that data understand these details.
Metadata relieves systems and users from having to have full advance knowledge of the characteristics of resources which it may use. This allows for a powerful "decoupling" effect which is necessary to make distributed applications.
And metadata serves is as a record in search systems so that users can locate data sets of interest.
Metadata is essential for machine-to-machine communication.
Ok but what's a metalanguage?
A metalanguage is a language about a language, or more specifically, a language which gives you guidance for making other languages. Our alphabet can be described as a metalanguage. In computing, XML is an example of a metalanguage. The languages which software engineers, or spec writers, author with this language might also be referred to as a vocabulary or a specification. Metalanguages help to enforce a general amount of structure and shared information across the vocabularies they govern but establish a means for the independent creation and development of highly specialized languages.
Would an example of Matadata be an airline company? When customers go to book a flight, they do not have to scroll through thousands of pages of available dates and seats to find the flight they are wanting to travel on. They just simply type in their information and the matching flights are found and shown to the customer. This makes it much more convenient and efficient for the customer. If they would had to find the flight by sifting through the thousands of pages, they probably would get discouraged and decide to drive or find another way.
Posted by: Cayla Leger | Nov 27, 2007 11:56:20 AM
I was wondering, on the back of a dvd case, there is also "details" of the dvd such as: running time, viewing format (wide or full view), the names of actors and producers,distributors, available languages, genre,the actual disc format, etc. Would this be an example of Metadata? In my mind this is all data about the content and form of the data in the dvd.... would this example fit the definition, or am I way off?
Posted by: Ashley Gallant | Nov 28, 2007 10:22:57 AM
So 0's and 1's are also considered metalanguage? This binary code describes all language on a computer, doesn't it?
Posted by: Chad MacLean | Nov 29, 2007 9:05:11 AM
Let me get this right. basically anything can be considered metadata depending on your frame of reference. A library catalog card can be metadata about a book. The "Author" field can be considered metadata of the card. Even the "t" it the word author can be considered metadata about that word because it describes something about the word - "this word contains a T." Is this right Mark or am I out to lunch?
Posted by: Chad Hayward | Nov 29, 2007 9:40:19 AM
Metadata is everywhere! Most information in a database would be considered metadata, right?
Posted by: Krista Mackenzie | Nov 29, 2007 5:46:45 PM
So, would I be right in saying that when we sell used textbooks online we describe them using metadata. For instance when we say "heavily used" this would be in relation to the form of the book. Then when we say it is biology book, that would be in relation to the content?
Posted by: Krista Mackenzie | Nov 29, 2007 6:28:48 PM
So basically I am getting from everyones posts that meta data is basically anything that can be assigned to something to explain it or present it?
Posted by: Alesia Gallant | Nov 29, 2007 7:42:13 PM
Ya I was also a little confused in class with this topic, because it seems like everything can be described as metadata. So what isn't metadata? Or maybe everything is metadata, i understand in Chad's post what each thing represents to the big picture but i just don't understand what isn't metadata?
Posted by: Carrie MacKay | Nov 29, 2007 8:02:27 PM
Hmmm id have to agree with Carrie...I get the idea of metadata (good examples for sure!) but what differs metadata to just plain instructions or descriptions. Are we just looking into it too much? hahaha
Posted by: Susanne | Nov 30, 2007 11:14:20 AM
I have the agree as well. It seemed in class there were many people, including myself that were a little unsure of the exact meaning or example of what metadata really is. Is any type of orgainzational inventory system type thing considered metadata? This concept was one of the hardest for me to understand and get a good understanding of.
Posted by: Sarah MacKay | Nov 30, 2007 11:49:27 AM
I guess I wasn't the only one a little confused about the discussion of Metadata in class. In the context of a sentence would it be correct to say Metadata is like an adjective, like a noun can have lots of different adjectives that are used to describe the noun? I may be way off base here but that's the first thing I thought of, and if Metadata is everything how are we supposed to determine what is the actual data and what is it's metadata?
Posted by: Ally Power | Dec 2, 2007 12:12:04 PM
I think of Metadate in terms of the data being a book and the metadata being the information in the book so it's a book that has information about the book in it. Data about data..I could be totally off but that's what comes to mind.
Posted by: Katelyn Murnaghan | Dec 2, 2007 3:22:47 PM
Everytime I read the word metadata, relational database is the first thing that comes to mind. Relations between the data from two different tables can provide even more data. I guess it all depends on what's considered data in the first place.
Posted by: Nathan Snowie | Dec 2, 2007 10:44:01 PM
I'm in the same boat as nathan, when I first read the section on metadata a relational database came to mind. It's just another form of a relational database because your just putting information into different categories and then those into into other categories, so it becomes a never ending stream of data. It's like taking a system and separating it into its sub-systems. Am I anywhere close to hitting it? because I'm still trying to understand metadata.
Posted by: alex stevenson | Dec 2, 2007 10:52:30 PM
When I first read this weblog about metadata I thought I had a good understanding of what it was. However, in class the day we discussed it, I was confused because of some of the examples and debates that were going on in class. Now reading it over again and having my mind cleared, and using the newer examples I better understand what metadata is.
Posted by: Holly MacInnis | Dec 3, 2007 8:34:40 PM
When I read this post before class and listened to the discussion in class I understood what metadata was or so I thought I did. Then the more examples people asked about the more confusing metadata was for me. Reading over it again for the exam gave me an even better undrestanding of it.
Posted by: Tiffany Richard | Dec 3, 2007 10:11:42 PM
as i read this post i understood what metedata was until i got to class and people were giving examples and then i was confused but now i think it understand it. Metadata is an object and then there is pieces of information inside about the object?
Posted by: Jolene | Dec 4, 2007 12:47:54 PM
Hmm, when alex brought up the database it got me to thinking.
If you were making a database for the upei library, the metadata would be the words letters and numbers that you use to fill in the fields?
Author: Salinger, J.D <--- J.D Salinger= metadata...
Posted by: Erica Wagner | Dec 4, 2007 7:33:05 PM
I like how chad explained Metadata. It really helped to point out that basically anything can be considered Metadata, anything that can be broken down I guess. As he put, simply the letter "t" in author could be considered metadata to that author. Once you see the big picture of what all data is made up of, it's simple to break it down into metadata.
Posted by: Kate MacDonald | Dec 4, 2007 7:45:56 PM
so basically metadata should be used instead of the word data from what i understand, because everything can be considered data about other data? i dunno, seems kind of weird to me. i dont think metadata should be used to describe something about itself, like my example in class. Blue Shoes. Is blue really metadata about the shoes, since it would be describing something about the shoes? and is the S really metadata about the word? because without the s it would be hoes, and that would completely change the meaning. can you acutally call something meta data if it wouldnt' be the same without it?
Posted by: Sean Hughes | Dec 4, 2007 10:20:03 PM
Metadata is like what Mark said in class with the library catalogue cards. You have books (data) arranged in a certain way and a catalogue card helps you find a specific book in a big library quicker by knowing its information (author, publisher, name) and therefore the catalogue card is data about the books, which is also data.
Posted by: Colin Butler | Dec 4, 2007 10:44:09 PM
Metadata can be almost anything but are we suppose to be more concerned with how data can be used to find other data in a more effective way. Like the eample of the library catalogue which has data about the books which can help you find the books easier.
Posted by: kyle macdonald | Dec 4, 2007 11:08:33 PM
I remember always wondering what the use of the Properties of a word.doc were and why it was there. I now realize that Metadata is crucial to any bigger picture data because it can tell you how to view, find, or go about the main data in which you are interested in.
Posted by: Jordyn Woodside | Dec 5, 2007 8:06:16 AM