Data

What is data?

• Processed information

• Raw facts and figures

• Cleaned dataset

• Insights

Which is a source of data collection?

• SQL databases

• Web scraping

• Sensors

• All of the above

Structured data is typically stored in:

• Tables with rows & column

• Social media posts

• Images and videos

• JSON files

Which of these is unstructured data?

• Excel sheet

• SQL table

• Text documents

• Customer transaction records

What is the main goal of data pre-processing?

• Collect more data

• Transform raw data into usable format

• Delete unnecessary records only

• Store data securely

“Garbage in, garbage out” highlights the need for:

• Fast algorithms

• Good data quality

• Big storage

• More variables

Handling missing values is part of:

• Data Integration

• Data Transformation

• Data Cleaning

• Data Reduction

Normalization (scaling) is used to:

• Remove duplicates

• Adjust data to a common range

• Combine multiple datasets

• Compress data

PCA is an example of:

• Data Cleaning

• Dimensionality Reduction

• Data Transformation

• Data Compression

In the data science workflow, which comes first?

• Pre-processing

• Model building

• Data collection

• Prediction