by Diego Parker

# Week Four (02/01/19 – 04/01/19)

###### A new year has started and DS12 has a lot of exciting challenges during the coming weeks!

As we started week four on Wednesday, I decided to put everything together in a single section, especially because we covered Tableau Intermediate most of the week (with a morning of Data Security). The week went very fast and it felt a bit like those small recap episodes between the seasons of a TV program. However, one of the exciting things about this week was that we had sessions with three different members of the core team that we hadn’t had before: Benedetta, Gwilym and Dan.

### What did we do this week?

##### The week was about Tableau Intermediate…

As we approached Tableau Intermediate we inevitably had to go back to essentials for a small review.

The first part that we covered in intermediate was Order of Operations, a topic that is easy to overlook but that can be the source of many headaches. Because this is just a journal I won’t go deep into what the order of operations is (you can read about it here) but basically it represents the order in which Tableau will apply the different filters and calculations. This was the introduction to different types of filters, particularly context filters, which are great to avoid dashboards with multiple filters going blank.

Moving into a more hands-on topic, we started by revising Table Calculations which we had seen before but now we covered in more depth. Benedetta gave us a lot of different exercises to follow and taught us a few things or two about parameters along the way. Whilst she also introduced us to Level of Detail Expressions (LODs), most of it was covered by Dan.

As a brief description, table calculations are a set of calculations that interact with your current view. These have a few differences from “normal” calculations. For instance, instead of working with your whole data, table calculations only refer to the displayed data. Another difference is that they allow you to give statements to your formula that refer to the position of the data. For example, you can create calculations that compute the data by cell, pane or table, both horizontally or vertically. On the other hand, LODs are calculations that allow us to compute different levels of granularity within our data (this is probably a very basic description).

##### …and Data Security

Besides our introduction to Tableau Intermediate, we also had a session about Data Security with Gwilym. As we are probably going to work with sensitive data from our clients, the session was about understanding our legal, ethical and moral obligations. Therefore, we started talking about GDPR regulations and different aspects we should keep in mind when handling sensitive data, such as our data processor role. We also talked about keeping the data safe and some good/bad practices. For example, we talked about confidentiality, guidelines when sharing information, keeping our computers safe and locked and correct use of credentials. Regarding the ethical and moral obligations, we talked about misuses of data, using the correct KPI’s and measures, biases and conflicts of interest. To sum up, big amounts of data come with a big responsibility.

This week we didn’t have a project as such. Instead, we had to show the different stuff we had been doing during our Christmas break, such as Alteryx challenges or MakeoverMonday.

If you have any doubts or comments feel free to use the box below or contact me in Twitter @DiegoTParker

Diego Parker

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