Visualization for Librarians: Glossary

Visualization comes in many forms and variations.

It is not straightforward to create reliable and engaging visualizations, and one has to keep in mind our cognitive biases.

When viewing visualizations made by others, always keep an eye open for ‘visualization lies’

Pivot tables are data summarization tools, useful to quickly summarize data

Pivot tables can be useful for doing exploratory data analysis, but also for visualization

Data understanding and cleaning is still of key importance

Column chart visualizations should be used when having 7 categories or less

Bar charts should be used when having more than 7 categories

Pie charts should only be used with caution

{“Three types of variables”=>”numerical, ordinal (inherent order), and categorical (no inherent ordering).”}

Using formulas in a spreadsheet editor, it is possible to convert values in more convenient formats for visualization.

Line charts are a useful way to depict temporal data, but equal intervals should be used.

Stacked charts may look visually appealing, but cannot be used for exact comparisons.

Various other charts exist to show temporal changes, such as GANTT charts (often used for project planning).

There are several formulas useful for clustering data (e.g., selecting the first or two characters of a column value)

RAWGraphs extends the visualization possibilities of Google Spreadsheets and Excel, it is open source, and easy to use for everyone

We confirmed, once more, that data have to be normalized and completed to generate useful visualizations

Using “scripts” in Google spreadsheets can be useful for these normalization and completion tasks

Maps can visualize quantitative information

Using Pivot tables, one can prepare data for visualization on maps

An important part of geomapping is ‘geocoding’, getting the geographical coordinates of a place described in a textual field

Specialized tools, such as Google Fusion Tables (free), or a variety of paid tools (e.g., Tableau), offer more advanced functionality for geomapping than tools like Google Spreadsheets.

Using RAWgraphs you can try out graphs that give more possibilities than the Excel spreadsheets, for example, alluvial diagrams

Scatterplots are graphs useful for showing correlations, distributions, and trends