To begin, we should define what data is. You will find varying definitions but I would define data as the digital persistence of facts, knowledge, and information consolidated for reference or analysis. The focus of my definition should be the word persistence because digital facts remain even after the computers used to create them are powered down and they are retrievable for future use. Rather than focus on the formal definition, let's discuss the world of data and how it impacts our daily lives. Whether you are reading a review to decide which product to buy or viewing the price of a stock, consuming information has become significantly easier to allow you to make informed data-driven decisions.
Data has been entangled into products and services across every industry from farming to smartphones. For example, America's Grow-a-Row, a New Jersey farm to food bank charity, donated over 1.5 million pounds of fresh produce to feed people in need throughout the region each year, according to their annual report. America's Grow-a-Row has thousands of volunteers and uses data to maximize production yields during the harvest season.
As the demand for being a consumer of data has increased, so has the supply side, which is characterized as the producer of data. Producing data has increased in scale as the technology innovations have evolved. I'll discuss this in more detail shortly, but this large scale consumption and production can be summarized as big data. A National Institute of Standards and Technology report defined big data as consisting of extensive datasets
—primarily in the characteristics of volume, velocity, and/or variability—
that require a scalable architecture for efficient storage, manipulation, and analysis.
This explosion of big data is characterized by the 3Vs, which are Volume, Velocity, and Variety,and has become a widely accepted concept among data professionals:
- Volume is based on the quantity of data that is stored in any format such as image files, movies, and database transactions, which are measured in gigabytes, terabytes, or even zettabytes. To give context, you can store hundreds of thousands of songs or pictures on one terabyte of storage space. Even more amazing than the figures is how much it costs you. Google Drive, for example, offers up to 5 TB (terabytes) of storage for free according to their support site.
- Velocity is the speed at which data is generated. This process covers how data is both produced and consumed. For example, batch processing is how data feeds are sent between systems where blocks of records or bundles of files are sent and received. Modern velocity approaches are real time, streams of data where the data flow is in a constant state of movement.
- Variety is all of the different formats that data can be stored in, including text, image, database tables, and files. This variety has created both challenges and opportunities for analysis because of the different technologies and techniques required to work with the data.
Understanding the 3Vs is important for data analysis because you must become good at being both a consumer and producer of data. The simple questions of how your data is stored, when this file was produced, where the database table is located, and in what format I shouldstore the output of my analysis of the data can all be addressed by understanding the 3Vs.
This leads us to a formal definition of data analysis which is defined as a process of inspecting, cleansing, transforming, and modeling data with the goal of discovering useful information, informing conclusion, and supporting decision-making, as stated in Review of business intelligence through data analysis.
What I like about this definition is the focus on solving problems using data without the focus on which technologies are used. To make this possible there have been some significant technological milestones, the introduction of new concepts, and people who have broken down the barriers.
To showcase the evolution of data analysis, I compiled a few tables of key events from the years of 1945 until 2018 that I feel are the most influential. The following table is comprised of innovators such as Dr. E.F. Codd, who created the concept of a database to the launch of the iPhone device that spawned the mobile analytics industry.
The following diagram was collected from multiple sources and centralized in one place as a table of columns and rows and then visualized using this dendrogram chart. I posted the CSV file in the GitHub repository for reference: https://github.com/PacktPublishing/python-data-analysis-beginners-guide. Organizing the information and conforming the data in one place made the data visualization easier to produce and enables further analysis:
That process of collecting, formatting, and storing data in this readable format demonstrates the first step of becoming a producer of data. To make this information easier to consume, I summarize these events by decades in the following table:
Decade |
Count of Milestones |
1940s |
2 |
1950s |
2 |
1960s |
1 |
1970s |
2 |
1980s |
5 |
1990s |
9 |
2000s |
14 |
2010s |
7 |
From the preceding summary table, you can see that the majority of these milestone events occurred in the 1990s and 2000s. What is insightful about this analysis is that recent innovations have removed the barriers of entry for individuals to work with data. Before the 1990s, the high purchasing costs of hardware and software restricted the field of data analysis to a relatively limited number of careers. Also, the costs associated with access to the underlying data for analysis were great. It typically required higher education and specialized careers in software programming or an actuary.
A visual way to look at this same data would be a trend bar chart, as shown in the following diagram. In this example, the height of the bars represents the same information as in the preceding table and the Count of Milestone events is on the left or the y axis. What is nice about this visual representation of the data is that it is a faster way for the consumer to see the upward pattern of where most events occur without scanning through the results found in the preceding diagram or table:
The evolution of data analysis is important to understand because now you know some of the pioneers who opened doors for opportunities and careers working with data, along with key technology breakthroughs, significantly reducing the time to make decisions regarding data both as consumers and producers.