An Overview of Data Science
Data Science is the theory and practice that transforms large and small data sets into useful information.
The figure above  gives a snapshot of data science jobs for 2016. It shows the number of jobs across Europe increasing in just a few months. Figure 1 below shows the exponential increase in interest in data science jobs given by Google Trends .
Figure 1. Google searches on ‘data science jobs’ 2004-2018
A huge amount of data is available on the internet. Converting it into useful information involves the following processes:
Data Preparation: Data sets from the internet often have problems such as missing items, errors, miscoding, and text that requires encoding. Data sets may use different classification schemes that require conversion before they can be combined for analysis. Data Preparation is the essential step of collecting data and cleaning it prior to analysis. This often requires considerable expertise and experience.
Data Analysis: Once data sets are clean and well structured they can be analysed using a wide range of analytic and statistical techniques. These are chosen to provide the information required.
Data Visualisation: Although some people can ‘read’ tables and other numerical data formats, most of us find it helpful to use graphical displays. This includes displaying data as bar charts and pie charts which are widely used to monitor key statistics and include in written reports. For example, the bar chart above shows estimates of the number of data scientists in European countries in 2016. Although simple, this chart conveys a lot of information. It shows the number of data scientists ordered by country (UK, France, Germany, Netherlands, Spain, Italy, Switzerland, Belgium, Ireland, and Poland). It clearly shows the increase in numbers between January and August 2016 across all European countries . Similarly, the Google Trends graphs and maps instantly communicate the increasing interest in data science jobs worldwide.
In the next step it will be seen that Google Analytics performs all these functions. It automatically collects a wide variety of data about website usage, analysing and displaying it in ways that are easy to understand.
 Data Scientists in Europe. Image source: Procorre 2016 (no longer available online)
 Google Trends. Accessed 3-Oct-2018
 C. Cristalli et al, Towards a Data-driven Mind-Set, Erasmus DA.RE. Project, 2017.