DS105 2025-2026 Autumn Term Icon

πŸ’» Week 09 Lab

Data Exploration and Visualisation Workshop

Author

Dr Jon Cardoso-Silva

Published

28 November 2025

πŸ₯… Learning Goals

By the end of this lab, you should be able to: i) Recognise when to use bar plots, box plots, and error bars appropriately, ii) Explain why pie charts often fail for comparisons, iii) Apply visualisation principles from research to your ✍️ Mini-Project 2 work, iv) Critique visualisation choices using evidence-based guidelines.

This lab builds on the πŸ–₯️ Week 09 Lecture discussion of exploratory data analysis principles. Your class teacher will facilitate a conversation about DOs and DON’Ts of visualisation to help you make better choices for your ✍️ Mini-Project 2.

πŸ“‹ Preparation

πŸ›£οΈ Lab Roadmap

Part Activity Type Focus Outcome
Part I πŸ‘€ TEACHING MOMENT Chart types: what’s good vs bad Understand when to use different visualisation types
Part II 🎯 ACTION POINTS Hall of Fame/Shame Share examples and critique visualisations

πŸ‘‰ NOTE: Whenever you see a πŸ‘€ TEACHING MOMENT, this means your class teacher deserves your full attention!

Part I: Chart Types Discussion (60 min)

Your class teacher will discuss examples of what types of data work well with different chart types and what they are bad for. They will use Friends Don’t Let Friends Make Bad Graphs and may reference other visualisation resources.

C. Li. (2023). cxli233/FriendsDontLetFriends: FriendsDontLetFriends (v3) (Version v3). Zenodo. https://doi.org/10.5281/zenodo.7542491

Your class teacher will cover these four points:

  1. Use bar plots for counting stuff, not for averages

  2. To communicate uncertainty, use box plots or error bars (but understand what they represent: Q1/Q3, median, etc.)

  3. Pie charts are confusing and often not a good idea

  4. Don’t plot too many line plots (spaghetti plots). At best, highlight one versus the rest.

Part II: Hall of Fame/Shame (30 min)

🎯 ACTION POINTS

  1. Go to the #social channel on Slack and locate the threads titled β€œHall of Fame” and β€œHall of Shame”

  2. Share a screenshot or link to your favourite and least favourite visualisations

  3. Be ready to explain your choices using the principles discussed in Part I