Data Visualization Visualization Tools and Software 2

Question 1

What is the purpose of Tableau's 'LOD (Level of Detail) expressions'?

Accepted Answer

Control the granularity of calculations independent of the visualization's current view level

Answer

Tableau LOD expressions (FIXED, INCLUDE, EXCLUDE) allow calculations at a specified level of data granularity regardless of what dimensions are in the current view.

Question 2

In Power BI, what is the purpose of 'relationships' between tables?

Accepted Answer

Defining how tables connect via key fields so data can be filtered and analyzed across tables

Answer

Relationships in Power BI's data model connect tables via primary/foreign key columns, enabling cross-table filtering and analysis in a star or snowflake schema.

Question 3

What does the term 'grammar of graphics' (as in ggplot2) refer to?

Accepted Answer

A structured framework describing charts as combinations of data, aesthetics, geometries, and scales

Answer

The grammar of graphics, formalized by Leland Wilkinson and implemented in ggplot2, decomposes visualizations into composable layers: data, aesthetics mappings, geometric objects, scales, and facets.

Question 4

What is Apache Superset primarily used for?

Accepted Answer

An open-source business intelligence and data visualization platform

Answer

Apache Superset is an open-source BI platform that provides interactive dashboards and chart exploration connected to various SQL databases.

Question 5

In Tableau, what is the 'Marks card' used for?

Accepted Answer

Controlling visual encoding properties like color, size, shape, label, and detail for marks in a view

Answer

The Marks card in Tableau controls how individual data marks are displayed, including their color, size, shape, opacity, tooltip content, and detail granularity.

Data Visualization Practice Test

Data Visualization Practice Test

Data Visualization Visualization Tools and Software 2