๐Ÿ•ถ The Nature of Data

Where does Data come from?

Let us look at the slides.

Why Describe and Graph Data?

  • Summaries are compressed data
  • 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.
  • Business Data Viz includes shapes that carry strong cultural and business 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:

What are Data Types??

https://www.youtube.com/watch?v=dwFsRZv4oHA

In more detail:

How do we Spot Data Variable Types?

By asking questions!

Pronoun Answer Variable / Scale Example What Operations?
What, Who, Where, Whom, Which Name, Place, Animal, Thing Qualitative / Nominal Name
  • Count no. of cases
  • Mode
How, What Kind, What Sort A Manner / Method, Type or Attribute from a list, with list items in some โ€ order**โ€ ( e.g.ย good, better, improved, best..) Qualitative / Ordinal
  • Socio -economic status (โ€œlow income, middle income, high income)

  • education level

    (โ€œhigh schoolโ€, โ€œB Sโ€,โ€ M Sโ€,โ€œPhDโ€)

  • income level

    (โ€œless than 50Kโ€, โ€œ50K-100Kโ€, โ€œover 100Kโ€)

  • Satisfaction rating ( โ€œextremely dislikeโ€, โ€œdislikeโ€, โ€œneutralโ€, โ€œlikeโ€, โ€œextremely likeโ€).

  • Median
  • Percentiles
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).
  • Year of Starting in College
  • Mean

  • Standard Deviation

How Many / Much / Heavy? Few? Seldom? Often? When?

Quantities, with Scale and a Zero Value.

Differences and Ratios /Products are meaningful. (e.g Weight )

Quantitative / Ratio**
  • Weight,length,Height

  • Temperature in Kelvin

  • Enzyme activity, dose amount, reaction rate, flow rate,concentration

  • Pulse

  • Survival time

  • Correlation
  • Coeff of Variation

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. 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.

References and Reading

  1. Datasets Have Worldviews,https://pair.withgoogle.com/explorables/dataset-worldviews/
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