Stephen Few, a data visualization guru, shares how organizations like the CIA teach new spy recruits to make observations. They're trained to first get an overview of what's going on around them and then when they spot something abnormal, they shift from a broad observational alertness to more focused perspective, in which they analyze the details. In this module, you'll learn how to use power BI to do with data, what spies do when observing their surroundings, get an overview of the data and then narrow in on certain aspects of the data that seem abnormal and analyze them. Stephen Few goes on to further quote some data visualization colleagues about why this approach is so useful. Having an overview is very important, it reduces search, allows detection of overall patterns, and aids the user in choosing the next move. A general heuristic of visualization design, therefore, is to start with an overview. But it is also necessary for the user to access details rapidly. One solution is overview plus detail; to provide multiple views, an overview for orientation and a detailed view for further work. In fact, there's something called Schneiderman's Mantra, which is overview first, zoom and filter, then details-on-demand. Now Powered BI is a great tool for implementing Schneiderman's Mantra because it is optimized for visualizing data, and so making charts is very quick and intuitive. Power BI is so intuitive it empowers many people, including those who do not have coding skills to make a wide variety of charts and then to use those charts to zoom in and filter the data to get a more focused perspective. With respect to the Business Analytic Workflow, Power BI excels Exploratory Data Analysis. In some sense, Power BI is like a grown up version of Excel's pivot table and pivot chart functionality, like excel, Power BI is pretty intuitive to use and you don't need to know much about programming to use it. Also, like Excel, Power BI has a really powerful tool for interacting with the data. The Power Query Editor, you can manipulate the shape of the data from wide to long. You can create new fields that are based on calculations of other fields. You can split or combine text fields. You can also perform Joynes and Lookups. Thus, many of the key assembly processes that can be done in excel, can also be done in the Power Query Editor. The method for doing so is different, because you can't point and click on cells to make changes. However, the benefit is that you can handle much larger amounts of data. While Power BI is a very powerful tool, it is only a tool unless you have first framed a question and then have access to relevant data, which are the first two parts of the fact framework, then you're not as likely to convert data into action even when you do have a well framed question and good data, obtaining actionable insights is not a straightforward process. Quoting his data visualization colleagues, Stephen Few writes, "users often try to make a good choice by deciding first what they do not want, that is, they first try to reduce the data set to a smaller, more manageable size. After some iterations, it is easier to make the final selections from the reduced data set. This iterative refinement of progressive querying of data sets is sometimes known as hierarchical decision making." Now, in my experience, I found that this quote is accurate. Power BI helps with this hierarchical decision making process by using visualizations to identify and communicate useful relationships in the data. This lessons are not meant to be a comprehensive tutorial on Power BI. There are many excellent tutorials for becoming familiar with all the bells and whistles of Power BI. The objectives of this module are for you to; one, identify the strengths and weaknesses of Power BI, for assembling data and Exploratory Data Analysis through hands on practice. Two use the Power Query Editor to assemble and preprocess data. Three, create basic charts in Power BI for exploring and communicating business data, and four, combine multiple charts into a report that can be published for use by others.
