What does it take to qualify as 'Big Data'?
If you've been on a deserted island for a couple of decades, you may not have heard the hot new buzz phrase: Big Data. And you many not have heard of "Hadoop", the application that accidentally solved the problem of Big Data.
Hadoop was originally designed as a way for the open source Nutch crawler to store its content prior to indexing. Nutch was fine for crawling sites; but of you wanted to crawl really massive data sets – say the Internet – you needed a better way to store the content (thank goodness Doug Cutting didn’t work at a database giant or we’d all be speaking SQL now!) GigaOm has a great series on the history of Hadoop http://bit.ly/1jOMHiQ I recommend for anyone interested in how it all began and evolved,
After a number of false starts, brick walls, and subsequent successes, Hadoop is a technology that really enables what we now call ‘big data’- usually written as "Big Data". But what does this mean? After all, there are companies with a lot of data – and there are companies with limited content size that changes rapidly every day. But which of these really have data that meets the 'Big" definition.
Consider a company like AT&T or Xerox PARC, which licenses its technology to companies worldwide. As part of a license agreement, PARC agrees to defend its licensees if an intellectual property lawsuit ever crosses the transom. Both companies own over tens of thousands patents going back to its founding in the early 20th century. Just the digital content to support these patents and inventions must number on the tens of millions of documents, much of which is in formats no longer supported by any modern search platform. Heck, to Xerox, WordStar and Peachtext probably seem pretty recent! But about the only time they have to access their content search is when a licensee needs help defending a licensee against an IP claim. I don’t know how often that is, but I’d bet less than a dozen times a year.
Now consider a retail giant like Amazon or Best Buy. In raw size, I’d bet Amazon has hundreds of millions of items to index: books, products, videos, tunes. Maybe more. But that’s not what makes Amazon successful. I think it’s the ability to execute billions of queries every day – again, maybe more – and return damn good results in well under a second, along with recommendations for related products. Best buy actually has retail stores, so they have to keep purchase data, but also buying patterns so they know what products to stock in any given retail location.
A healthcare company like UnitedHealth must have its share of corporate intranet content. But unlike many corporations, these companies must process millions of medical transactions every week: doctor visits, prescriptions, test results, and more. They need to process these transactions, but they also must keep these transactions around for legally defined durations.
Finally, consider a global telecom company like Ericsson or Verizon. They’ve got the usual corporate intranet, I’m sure. They have financial transactions like Amazon and UHG. But they also have telecomm transaction records that must count in the billions a month: phone calls and more. And given the politics of the world, many of these transactions have to be maintained and searchable for months, if not years.
These four companies have a number of common traits with respect to search; but each has its own specific demands. Which ones count as ‘big data’ as it’s usually defined? And which just have ‘a bunch of content?
As it turns out that’s a touch question. At one point, there was a consensus that ‘big data’ required three things, known as the “Three V’s of Big Data’. This escalated to the ‘5 V’s of Big Data’, then the “7 V’s”– and I’ve even seen some define the “10 V’s of Big Data”. Wow.. and growing!
Let’s take a look at the various “V’s” that are commonly used to define ‘Big Data’.
Depending on who you ask, there are four, five, seven or more ‘requirements’ that define ‘big data. These are usually referred to as the “Vs of Big Data”, and these usually include:
Volume: The scale of your data – basically, how many ‘entries’ or ‘items’, you have. For Xerox, how many patents; for a telecom company, how many phone ‘transactions’ have there been.
Variety: Basically this means how many different types of data you have. Amazon has mouse clicks, product views, unique titles, subscribers, financial transactions and more. For UHG and Ericsson, I’d guess the majority of their content is transactional: phone call metadata (originating and receiving phone number, duration of the call, time of day, etc.). In the enterprise, variety can also mean data format and structure. Some claim that 90% of enterprise data is unstructured, which adds yet another challenge.
Veracity: The boils down whether the data is trustworthy and meaningful. I remember a survey HP did years ago to find out what predictors were useful to know whether a person waking into a random electronics store would walk out with an HP PC. Using HP products at work or at home we the big predictors; but the fact that the most likely day was Tuesday was perhaps spurious and not very valuable.
Velocity: How fast is the data coming in and/or changing. Amazon has a pretty good idea on any given day how many transactions they can expect, and Verizon knows how much call data they can expect. But things change: A new product becomes available, or a major world event triggers many more phone calls than usual.
Viability: If you want to track trends, you need to know what data points are the most useful in predicting the future. A good friend of mine bought a router on Amazon; and Amazon reported that people who bought that router also bought.. men’s extra large jeans. Now, he tells me he did think they were nice jeans, but that signal may not have had long viability.
Value: How useful or important is the data in making a prediction, or in improving business decisions. That was easy!
Variability: This often refers to how internally consistent the data is. To a data point as an accurate predictor, that data point is ideally consistent across the wide range of content. Blood pressure, for example, is generally in a small range; and for a given patient, should be relatively consistent over time. When there is a change, UHG may want to understand the cause.
Visualization: Rows and columns of data can look pretty intimidating and it’s not easy to extract meaning from them. But as they say, ‘a picture is worth a thousand words’, so being able to see charts or graphs can help meaning and trends jump out at you. I’d use Lucidworks’ SiLK product as an example of a great visualization tool for big data, but there are many others.
Validity: This seems like another way to say the data has veracity, but it may be a subtle point. If you’re recording click-thru data, or prescriptions, or intellectual property, you have to know that the data is accurate and internally consistent. In my HP anecdote above, is the fact that more people bought HP PCs on Tuesday a valid finding? Or is it simply noise? You’ll probably need a human researcher to make these kinds of calls.
Venue: With respect to Big Data, this means where the data came from and where it will be used. Content collected from automobiles and from airplanes may look similar in a lot of ways to the novice. In the same way, data from the public Internet versus data collected from a private cloud may look almost identical. But making decisions for your intranet based on data collected from Bing or Google may prove to be a risk.
Vocabulary: What describes or defines the various items of the data. Ericsson has to know which bit of data represent a phone number and which represent the time of day. Without some idea of the schema or taxonomy, we’ll be hard pressed to reach reasonable decisions from Big Data.
Volatility: This may seem like velocity above, but volatility in Big Data really means how long is the data value, how long do you need to keep it around. Healthcare companies may need to keep the data a lot longer than
Vagueness: This final one is credited to Venkat Krishnamurthy of YarcData just last month at the Big Data Innovation Summit here in Silicon Valley. In a way, it addresses the confidence we can have in the results suggested by the data. Are we seeing real trends, or are we witnessing a black swan?
In the application of Big Data not all of these various V’s are as valid or valuable to the casual (or serious) observer. But as in so many things, interpreting the data is to the person making the call. Big Data is only a tool: use it wisely!
Some resources I used in collection data for this article include the follow web sites and blogs:
See also Dr. Kirk Borne’s Top 10 List on Data Science Central
Bernard Marr’s LinkedIn post on The 5 Vs Everyone Must Know