MGMT 3125 Introduction to Data Visualization

Transcription

1 MGMT 3125 Introduction to Data Visualization John Sokol, MS Week 2 1/30/2019 Chapter 2: Choose an effective visual

2 Agenda Chapter 2: Choose an effective visual Introduction to Tableau Week 2 action items

3 Circling back to last week

4 Six lessons Understand the context Choose an appropriate visual display Eliminate clutter Focus attention where you want it Think like a designer Tell a story

5 The 8 common visualizations 1. Simple text 2. Table 3. Scatterplot 4. Line graph 5. Single bar graph 6. Stacked bar graph 7. Heatmap (also known as treemap) 8. Slopegraph

6 Simple text Ideal for just a number or two to share. 80% 70% Denver Arrests: Crime vs. Traffic 75% 60% 50% 40% 30% 20% 10% OR of Denver arrests are considered crime, compared to 25% traffic violations. 0% IS_CRIME_TOTAL IS_TRAFFIC_TOTAL

7 Table Refrain from use in live presentations. Remove borders; allow the data to stand out.

8 Heatmap (aka treemap) Special table that emphasizes outlier values with color saturation. Remember to include a legend to convey color meaning.

9 Scatterplot Useful to visualize tens or hundreds of observations (rows) Show a relationship between variables; either independent- independent or independent-dependent. Effective way to deduce trend and regression lines.

10 Line graph Plot continuous data that naturally implies a connection between data points, notably time series.

11 Slopegraph Show relative increases or decreases between time periods or points of comparison Focuses on rate of change, beginning to end.

12 Bar graph The most common data visualization medium; encouraged as they are common for easy audience interpretation. The human brain is optimized to compare height. Must have a zero baseline

13 Rationale for zero baseline

14 Vertical bar graph Singleseries, two series or multiple series However, more series increases difficulty to read Best for short named categories

15 Horizontal bar graph EXTREMELY easy to read Preferred choice for long category names Flows with natural tendency to look at top left of graph first

16 Stacked bar graph Visualize sub-components across categories. Not useful for static purposes; comparing sub-components isn t feasible However, Tableau can help with this issue.

17 Bar graph width

18 To be avoided Pie chart/donut chart 3D charts Secondary y-axis

19 To be avoided Pie chart Difficult for people to read The human eye is optimized to discern height, not area Alternative? Bar graph

20 To be avoided 3D 3D skews the graph numbers Introduces unnecessary chart elements. Unable to estimate dependent variable value Alternative? 2D visualizations

21 To be avoided Secondary y-axis Takes time and effort to understand which data corresponds to each axis

22 Secondary y-axis alternatives Label directly Pull apart vertically

23 Closing Consider the needs of the audience. Categorical data? Consider first horizontal bar graph Continuous data? Consider first line graph The best visualization? The one that is easiest for the audience to read.

24 Introduction to Tableau Open Tableau on your personal computer or labratory PC Import the IT Tickets dataset

25 Assignment 2 due 2/5 Reproduce IT tickets line graph Heart rate line graph Denver arrests/incidences bar graph

26 Week 2 action items due 11:59pm Quiz 2 Chapter 2: Choose an effective visual Assignment 2 Introduction to Tableau Discussion board 2 Your thoughts, comments, and opinions on the chapter 2 readings