Day 1: How did my first day go?
Like anyone would on their first day at work, I was quite nervous. But my nerves quickly disappeared as soon as I met my work coach and fellow cohort members. There were many many introductions, so you get to learn everyone pretty well and pretty fast.
We had a lovely chat with Tom Brown, the founder of TIL and co-found of the DS, who gave us the story of how they both began!
The afternoon consisted of Tech set up- so laptops, passwords, installing and understanding the platforms that will be used for communication and task management.
Day 2: The Learning Begins
Today I was introduced to the core concepts when it comes to Data Preparation, I will try and summarise them below.
Data Structure & Terminology
So what is the definition of the word data? Well it is actually a hard word to define but the definition we use is 'facts or numbers collected from observations for the purpose of understanding a particular subject better' - Data Curious, 2023 and there are endless ways in which it can be created.
And how do we interact with it? As a consultant we will Extract, Transform and Load ETL (or ELT). This means to extract the data from its origin, prep it for analysis and load it so it is accessible for its users. The resulting data can then be analysed and used. The process of sourcing, analysing and using appears linear but there is usually back and forth between the stages for better results.
Data Sources & Architecture
Now what are some examples of data sources? Data sources range from structured flat files (the most common) and databases to unstructured Data lakes.
Data is contained in databases, where the relationships between tables are mapped out in what is called a schema, with stars and snowflakes being examples of schemas.
Cleaning
It is important that data is 'clean', you can ensure data is clean by following the 4 rules:
-One data field for each category or measure
-One data type for each data field
A single date column where possible
-One row should be a record containing all the values in each data field possible
Now how to clean? Rename, split fields, filtering, correct spelling mistakes
Reshaping
Before learning how to reshape data, it is important to understand the concept of granularity, which in short is the level of detail of the data. It is best to avoid reducing granularity where possible.
So what are the ways to reshape data?
-Pivot, by converting columns to rows
-Unpivot by converting rows to columns
-Aggregating (eg. summarising data with averages totals)
Multiple Data Sources
In most cases there will be more than one data sources required. So the question is how to join them?
-Unions, stacks data on top of each other
-Joins (left, right, inner or outer), combining tables by a common field and join logic.
Day 3: A bit of everything
Day 3 was a whirlwind of a day. To begin with I continued teaching we continued with core concepts (see day 2).
We then took part in a session about consulting, where I was able to understand what is expected of me as a consultant and the services that TIL provides. One thing that I thought was interesting from this session was that constantly asking why, will reveal the true motivation behind a task.
We had our pictures taken in our DS shirts, and had a small intro to the weekly projects (see day 5)!
Day 4: Tableau Prep & Preppin
I think day 4 was my favorite of the week ! I was able to use all the theory I learned over the previous couple of days and put them to practice. After a mini tutorial of Tableau Prep, I was able to tackle a few of the Preppin Challenges- aimed on cleaning and preparing files for data analysis. I will admit I was a bit slow at first, but I really started to get the hang out it and enjoy it (to the point where I did not want to stop for breaks- whoops).
Day 5: My First Project & Presentation
To bring my first week at The Data school to a close, my cohort and I were given out first project and presentation. It was a data preparation task- another opportunity to utilise my new Tableau prep skills! I was nervous for the presentation, but its not so scary once you're up there! Plus the feedback and what you learn is more valuable than your presentation itself.
Amongst other things, the most important takeaway for me was to always thoroughly plan and document your work and so that it is easy for anyone to follow or pick up after you!
Final Thoughts
I really enjoyed my first week of training. What I gathered from this week, was that although something may seem new or daunting, do not let it deter you from trying! There is a high chance you will get it in the end and enjoy it! Oh and ask loads and loads of questions!!