πŸ•Ά Lab-1: Science, Human Experience, Experiments, and Data

Why do we visualize data

Author

Arvind V.

Published

November 1, 2021

Modified

May 21, 2024

Slides and Tutorials

   


Where does Data come from?

We will need to form a basic understanding of basic scientific enterprise. Let us look at the slides.

Why Visualize?

  • We can digest information more easily when it is pictorial
  • Our Working Memories are both short-term and limited in capacity. So a picture abstracts the details and presents us with an overall summary, an insight, or a story that is both easy to recall and easy on retention.
  • Data Viz includes shapes that carry strong cultural memories and impressions for us. These cultural memories help us to use data viz in a universal way to appeal to a wide variety of audiences. (Do humans have a gene for geometry?)
  • It helps sift facts and mere statements: for example:

Rape Capital

Rape Capital

What does Data Reveal?

What does Data Reveal?

What are Data Types?


In more detail:

How do we Spot Data Variable Types?

By asking questions!

No Pronoun Answer Variable/Scale Example What Operations?
1 How Many / Much / Heavy? Few? Seldom? Often? When? Quantities, with Scale and a Zero Value.Differences and Ratios /Products are meaningful. Quantitative/Ratio Length,Height,Temperature in Kelvin,Activity,Dose Amount,Reaction Rate,Flow Rate,Concentration,Pulse,Survival Rate Correlation
2 How Many / Much / Heavy? Few? Seldom? Often? When? Quantities with Scale. Differences are meaningful, but not products or ratios Quantitative/Interval pH,SAT score(200-800),Credit score(300-850),SAT score(200-800),Year of Starting College Mean,Standard Deviation
3 How, What Kind, What Sort A Manner / Method, Type or Attribute from a list, with list items in some " order" ( e.g. good, better, improved, best..) Qualitative/Ordinal Socioeconomic status (Low income, Middle income, High income),Education level (HighSchool, BS, MS, PhD),Satisfaction rating(Very much Dislike, Dislike, Neutral, Like, Very Much Like) Median,Percentile
4 What, Who, Where, Whom, Which Name, Place, Animal, Thing Qualitative/Nominal Name Count no. of cases,Mode

As you go from Qualitative to Quantitative data types in the table, I hope you can detect a movement from fuzzy groups/categories to more and more crystallized numbers.

Type of Variables

Type of Variables

Each variable/scale can be subjected to the operations of the previous group. In the words of S.S. Stevens

the basic operations needed to create each type of scale is cumulative: to an operation listed opposite a particular scale must be added all those operations preceding it.

What Are the Parts of a Data Viz?

How to pick a Data Viz?

Most Data Visualizations use one or more of the following geometric attributes or aesthetics. These geometric aesthetics are used to represent qualitative or quantitative variables from your data.

Common Geometric Aesthetics in Charts

Common Geometric Aesthetics in Charts

What does this mean? We can think of simple visualizations as combinations of these aesthetics. Some examples:

Geometries , Combinations, and Graphs
Aesthetic #1 Aesthetic #2 Shape
Position X = Quant Variable Position Y = Quant Variable P oints/Circles with Fixed Size
Position X = Qual Variable Position Y = Count of Qual Variable Columns
Position X = Qual Variable Position Y = Qual Variable Rectangles, with area proportional to joint(X,Y) count
Position X = Qual Variable Position Y = Rank-Ordered Quant Variable Box + Whisker, Box length proportional to I nter-Quartile Range, w hisker-length proportional to upper and lower quartile resp.
Position X = Quant Variable Position Y = Quant Variable + Qual Variable

Line and Area

Colour for Area

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