Handling Data - Data Points: Visualization That Means Something - page 40

machine-readable, or in other words, to structure your data in a way that a
computer can understand. Which data format you use can change by visu-
alization tool and purpose, but the three following formats can cover most
of your bases: delimited text, JavaScript Object Notation, and extensible
Markup Language.

DELIMITED TExT
Most people are familiar with delimited text. You did after all just make a
comma-delimited text file in your data scraping example. If you think of a
dataset in the context of rows and columns, a delimited text file splits col-
umns by a delimiter. The delimiter is a comma in a comma-delimited file.
The delimiter might also be a tab. It can be spaces, semicolons, colons,
slashes, or whatever you want; although a comma and tab are the most
common.

Delimited text is widely used and can be read into most spreadsheet pro-
grams such as excel or Google Documents. You can also export spread-
sheets as delimited text. If multiple sheets are in your workbook, you usu-
ally have multiple delimited files, unless you specify otherwise.

This format is also good for sharing data with others because it doesn't
depend on any particular program.

JAVASCrIPT obJECT NoTATIoN (JSoN)
This is a common format offered by web APIs. It's designed to be both
machine- and human-readable; although, if you have a lot of it in front of
you, it'll probably make you cross-eyed if you stare at it too long. It's based
on JavaScript notation, but it's not dependent on the language. There are a
lot of specifications for JSON, but you can get by for the most part with just
the basics.

 Visit http://
json.org for the
full specification
of JSON. You don't
need to know
every detail of
the format, but it
can be handy at
times when you
don't understand a
JSON data source.

JSON works with keywords and values, and treats items like objects. If
you were to convert JSON data to comma-separated values (CSV), each
object might be a row.

As you can see later in this topic, a number of applications, languages, and
libraries accept JSON as input. If you plan to design data graphics for the
web, you're likely to run into this format.