Tableau Data Visualization and Analytics 3 — Questions and Answers
Question 1: What is the difference between a calculated field and a parameter in Tableau?
- A calculated field derives values from data; a parameter is a user-controlled single value (Correct answer)
- They are identical in function
- A parameter stores multiple rows of data
- A calculated field can only return text
Correct 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.
Question 2: Which type of calculation in Tableau is computed using the local data after the query returns, such as RUNNING_SUM?
- Table calculation (Correct answer)
- Row-level calculation
- Aggregate calculation
- LOD expression
Correct answer: Table calculation
Table calculations operate on the aggregated results already in the visualization.
Question 3: What does a FIXED level-of-detail (LOD) expression do?
- Computes a value at a specified dimension level regardless of view detail (Correct answer)
- Filters rows before loading
- Sorts the data alphabetically
- Hides null values
Correct 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.
Question 4: Which function would you use to return the current date and time in a Tableau calculation?
- NOW() (Correct answer)
- TODAY()
- DATEPART()
- DATEDIFF()
Correct answer: NOW()
NOW() returns the current datetime, while TODAY() returns only the date.
Question 5: In Tableau, what does the IIF function evaluate?
- A single condition returning one of two values (plus a null option) (Correct answer)
- Multiple unrelated conditions in sequence
- A loop over rows
- A regular expression match
Correct 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.
Question 6: Which calculation type is evaluated for every individual record in the data source?
- Row-level calculation (Correct answer)
- Table calculation
- Aggregate measure
- Quick table calculation
Correct answer: Row-level calculation
Row-level calculations execute against each underlying record before aggregation.
Question 7: What does the ZN function help prevent in Tableau calculations?
- Errors or gaps caused by null values by replacing them with zero (Correct answer)
- Division overflow
- String concatenation issues
- Date parsing failures
Correct 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.
Tableau Data Visualization and Analytics 3
What is the difference between a calculated field and a parameter in Tableau?