Free Practice Quiz Question List

1 Introduction to Data Science Online Quiz Questions

Use this free practice quiz with 20 questions to review 1 Introduction to Data Science, test your knowledge, and prepare for your next test or exam.

20 questions

Choose one

1 point

A city is studying bus delays, but its records omit several routes. What is the most responsible way to handle this limitation when presenting findings?

A
Treat the routes represented in the data as a complete picture of the city.
B
Remove the routes that are missing from the records from the analysis without mentioning them.
C
Delay analysis until every route has supplied records, even if the available data could answer part of the question.
D
Report the route gap as a limitation and avoid presenting the results as universal.

Choose one

1 point

A software system must exchange a record containing a person's address and a list of observations. Which format is especially suited to representing this nested structure?

A
CSV, because it is designed specifically to represent nested records.
B
JSON, because it can represent nested structured data.
C
Parquet, because it stores every record as a name–value object.
D
CSV, because it requires a separate file for each list of observations.

Choose one

1 point

A team exchanges CSV files with different software tools and finds that quoted fields and missing values may be interpreted differently. What should the team do?

A
Assume every application interprets quoting and missing values in the same way.
B
Convert all CSV files to JSON before inspecting their contents.
C
Document relevant assumptions and verify how the software reads the file.
D
Ignore character encoding unless the file visibly contains errors.

Choose one

1 point

An analyst works with a large table and often retrieves only a few selected columns. Which format is a suitable option based on its design?

A
Parquet, because its column-oriented design can support efficient retrieval of selected columns.
B
JSON, because it is the only format that supports field names.
C
CSV, because it stores data by column and is always the most efficient for large analytical queries.
D
JSON, because ordered arrays make it the best choice for every large table.

Choose all

1 point

Which actions align with responsible data handling? Select all that apply.

A
Collect only the personal information needed for the defined purpose.
B
Limit access to people who need it and use appropriate safeguards.
C
Keep personal information indefinitely in case it might be useful later.
D
Record relevant definitions, changes, and known data gaps.
E
Explain important limitations and uncertainty when communicating results.
F
Share the complete dataset broadly so recipients can decide how to use it.

Choose all

1 point

After data have been prepared, which activities are part of the workflow? Select all that apply.

A
Analyze or model the prepared data using methods suited to the question.
B
Evaluate whether the results are reliable and address the original purpose.
C
Communicate or deploy findings and explain their limits.
D
Acquire data before deciding what question the project should answer.
E
Define the project purpose only after deploying the results.

True or false

1 point

A data science project must complete each workflow stage exactly once and in order; it should not revisit an earlier stage.

A
True
B
False

True or false

1 point

If a dataset has many records, it can be treated as representative of all relevant groups even when some groups are omitted.

A
True
B
False

Written response

1 point

What is the name for documentation that explains a dataset's field names, types, units, and meanings?

Written response

1 point

Which format stores rows and fields as text and is widely supported for simple tables?

Fill in the blank

1 point

Before selecting a tool or acquiring data, clarify the project's .

Fill in the blank

1 point

When CSV conventions may be ambiguous, document relevant and verify how software reads the file.

Open ended

1 point

A team corrects errors and combines data from several sources before analysis. Explain why it should document the transformations and decisions it makes.

Choose one

1 point

A team needs to exchange a small, flat table of daily temperatures with common data tools. Which format is the most natural fit?

A
CSV
B
JSON
C
Parquet

True or false

1 point

In a data science project, evaluation may reveal that the original question or approach needs revision.

A
True
B
False

Choose one

1 point

A city wants to understand whether bus delays are worsening. Before choosing software or collecting records, what should the project team do first?

A
Choose an analysis tool and then look for a question it can answer.
B
Acquire as much available data as possible before deciding how it will be used.
C
Clarify the question, intended users, and what evidence would count as a useful answer.
D
Prepare a final presentation before examining the data.

Choose one

1 point

Which statement accurately describes how JSON represents structured data?

A
It stores simple tables as rows and fields of text.
B
It represents structured data using objects of name–value pairs and ordered arrays.
C
It is a column-oriented format designed for efficient storage and retrieval.
D
It automatically documents the meanings and units of every field.

Written response

1 point

What data-handling principle means collecting only what is needed for a defined purpose?

Written response

1 point

Documenting data transformations and decisions helps others understand and repeat the work. What capability does this support?

Choose one

1 point

A team is designing a dataset for a narrowly defined service evaluation. Which plan best follows the principle of minimizing data collection and retention?

A
Collect every potentially useful field and keep it indefinitely in case the purpose changes.
B
Collect only what the defined purpose requires and retain personal information only as long as necessary.
C
Collect only fields that can be stored in CSV, regardless of their relevance.
D
Keep all collected information until the analysis is published, then share the full dataset.