Data Visualization and Analytics Flashcards

What is the difference between a calculated field and a parameter in Tableau?

Answer: A calculated field derives values from data; a parameter is a user-controlled single value

Calculated fields compute from underlying data while parameters are dynamic single values controlled by users.

Which type of calculation in Tableau is computed using the local data after the query returns, such as RUNNING_SUM?

Answer: Table calculation

Table calculations operate on the aggregated results already in the visualization.

What does a FIXED level-of-detail (LOD) expression do?

Answer: Computes a value at a specified dimension level regardless of view detail

FIXED LOD expressions aggregate at the dimensions you specify, independent of the view's granularity.

Which function would you use to return the current date and time in a Tableau calculation?

Answer: NOW()

NOW() returns the current datetime, while TODAY() returns only the date.

In Tableau, what does the IIF function evaluate?

Answer: A single condition returning one of two values (plus a null option)

IIF tests one condition and returns the true value, false value, or an optional value for unknown.

Which calculation type is evaluated for every individual record in the data source?

Answer: Row-level calculation

Row-level calculations execute against each underlying record before aggregation.

What does the ZN function help prevent in Tableau calculations?

Answer: Errors or gaps caused by null values by replacing them with zero

ZN returns zero in place of nulls, useful for continuous calculations and table calcs.