Today it was time to dive into the world of Tableau Prep. During a morning session with Carl he outlined the data preparation process from start to finish as follows:
Messy raw data -> Organise and clean -> Analyse -> Communicate
Within this session we also learnt about the concept of granularity, which was strange to wrap my head around to begin with but began to make a lot of sense by the end of the session! It essentially relates to the level of detail in a dataset and thus determines what types of analysis can be performed. Another key idea explained to us was the process of how to plan our data preparation, which consisted of four steps:
- Know your data - It is crucial to understand how our dataset is structured, what types of data are in the dataset, the granularity of the data, etc. This allows us to be able to deliver the results we set out for.
- The desired state - The aim as DS consultants is to be able to look at raw data and instantly know what the desired outcome should be.
- Logical transitions - Now we know our data and we know how we want the data to look after prepping, the next step is to work out how we get from the former to the latter! This is where the technical knowledge of the tools comes into play.
- Do it!
After the morning session, we were tasked with our first (of many) of Carl's Preppin' Data data preparation challenges. The aim of these challenges is to implement the planning process above and develop our Tableau Prep skills. Both challenges revolved around sales data from a fictional bike shop, with each challenge posting its own requirements detailing how the raw data is meant to be prepared. We were then given a time limit to complete these challenges. I found them not too difficult, but I did have some difficulty understanding the idea of aggregating the data by different levels which was necessary in the requirements of the second challenge.
I am excited to develop my skills by completing as many challenges as possible, as well as reaching as high as I can on the Preppin' Data participation tracker!