Creating Good Graphics TILT Information

Purpose

One of the most critical skills for statisticians and data scientists is to be able to communicate results effectively. Data visualization is a critical tool for communication - it leverages visual channels (higher bandwidth) and relays data based on the internal relationships that are displayed and highlighted graphically. This comes at a cost – we have to understand the human visual system in order to develop graphics that are effective.

Skills

This assignment will help you practice the following skills which are important for creating good data visualizations:

• Analyze graphics to determine effectiveness based on:

  • Use of Gestalt principles
  • Hierarchies of accurate estimation (geoms)
  • Appropriate geometric object representation

• Create graphics which are intended to communicate a specific message

• Carefully select annotations to assist users with appropriate interpretation of visualizations

• Consider accessibility when creating graphics and write appropriate alt-text for screen reader users

Knowledge

• Basic understanding of short term memory, color vision, Gestalt heuristics, and other concepts in cognitive psychology important for constructing data visualizations.

• Grammar of graphics syntax and layering mechanisms

Success Criteria

General Criteria

• Student’s name is included at top of assignment
• Document compiles on a different machine
• Compiled document is formatted well
• All code in the document is contained in appropriately formatted code chunks
• Compiled document does not include long sections of printed data, making use of head and tail commands to show only a few rows of data during data cleaning.
• Student answers are below the --- separator and above the next prompt, or in cases where questions are enumerated, student answers are indicated using the quote indicator, > and the placeholder text Your answer here has been removed and replaced with the answer.

Task specific Criteria

1. Graphical Critiques

• Each chart has an appropriate caption

• Each chart has appropriate alt-text that provides essential information to a visually impaired individual or screen-reader user.

• YAML chunk options are formatted correctly and compile.

• Grammar of graphics table is filled out correctly.

• Analysis of effective communication in each chart is reasonable.

  • Charts that ineffectively show changes in vaccine rates over time across different age groups
    • are identified and
    • an explanation of why they are ineffective is provided.
  • Charts that are appropriate but perhaps suboptimal
    • have issues identified and
    • what would be changed to address the issue is provided and appropriate.

• Gestalt principles of grouping

  • Principles that apply are ID’d for each chart
  • Principle effectiveness is evaluated

• Message Evaluation

  • Important messages from the data set are identified
  • Comparisons that should be easy to perform are identified
  • Obstacles are provided (if there are any, if not, “no obstacles” is an ok answer… but be careful with its use.)

• Improved chart is created, and changes relative to initial charts are explained.

  • Explanation focuses on each change and how it improves the chart/makes it easier to read.

2. Choose Your Own Adventure

• Population size estimates are calculated correctly for each year of data.
  • Population size is merged into the dataset appropriately
• Plot from 1.6 is generated using the real data.
  • Change to the message when using real data is examined
  • Analysis of change in difficulty when using real data is included
• Annotations
  • Suggested annotations are reasonable
  • Annotations do not over-clutter the chart
• Modifications to compare 2023 to 2024 vaccination rates are reasonable
  • Cognitive load considerations are included
  • Modifications actually make the comparisons easier for the reader
• Suggestions for statistical significance are reasonable and explanation is thorough.