Understanding Data

Topics in this chapter

• Data Sources and Structure
• Data Types and Attributes
• Data Collection and Sampling
• Data Quality and Cleaning
• Data Organisation and Context
• Data Analysis and Interpretation

Cheat sheet

Practice questions

1. Question 1Q-2EA479

   Which statement best distinguishes data from information?

   1. A.Data is always numerical, whereas information is always textual.
   2. B.Data consists of raw facts, while information is processed data with meaning.
   3. C.Data is stored only in computers, whereas information is stored only on paper.
   4. D.Data is useful only after it has been deleted, whereas information is useful before collection.
   See the answer and solution
2. Question 2Q-472F4F

   Differentiate between structured data and unstructured data. Give one suitable example of each and mention one reason why structured data is generally easier to analyse using conventional database tools.

   See the answer and solution
3. Question 3Q-1C7651

   A school records the following attributes for each student: roll number, date of birth, height in centimetres, number of siblings, blood group, and performance level (Poor, Average, Good, Excellent). Which classification is correct?

   1. A.Roll number is continuous, height is nominal, number of siblings is ordinal, and performance level is discrete.
   2. B.Roll number is nominal, height is continuous, number of siblings is discrete, and performance level is ordinal.
   3. C.Roll number is ordinal, height is discrete, number of siblings is continuous, and performance level is nominal.
   4. D.Roll number is discrete, height is ordinal, number of siblings is nominal, and performance level is continuous.
   See the answer and solution
4. Question 4Q-9E03A9

   Which of the following is an example of ordinal data?

   1. A.Names of cities: Delhi, Jaipur, and Mumbai
   2. B.Customer ratings: poor, average, good, and excellent
   3. C.Heights of students: 150, 162, and 175 cm
   4. D.Number of books issued: 2, 4, and 6
   See the answer and solution
5. Question 5Q-EF81DB

   A weather station stores the value 32.5 along with the details 'air temperature', 'degree Celsius', and '10:00 AM'. What do these additional details primarily represent?

   1. A.Metadata describing the data value
   2. B.Unstructured data replacing the data value
   3. C.Duplicate values generated from the data
   4. D.A primary key used to identify the weather station
   See the answer and solution