Classification and Tabulation

Definition: Classification groups raw data into homogeneous classes by a common characteristic; tabulation then arranges the classified data into rows and columns.

Bases of Classification

• Quantitative (by magnitude — e.g. income classes), Qualitative (by attribute — e.g. gender), Geographical (by region), Chronological (by time).

Parts of a Table

Title, stub (row headings), caption (column headings), body, head-note and foot-note.

Frequency Distribution

Data grouped into class intervals with their frequencies; may be discrete or continuous, and shown as a cumulative frequency (less-than / more-than) distribution.

Real-world example: Grouping exam scores into 0–10, 10–20 … bands with counts is a continuous frequency distribution.

Example 1. Classifying data by region (state-wise) is which type of classification?

• Geographical.

Example 2. In a statistical table, the column headings are called the:

• Caption.

Example 3. A distribution showing the count of values "less than" each class boundary is a:

• Cumulative frequency distribution.

Quick-revision notes for Classification and Tabulation — the must-know points for SSC CGL Tier-I/II.

• Classification arranges data into groups/classes based on common characteristics.
• Bases of classification: geographical, chronological, qualitative, and quantitative.
• Tabulation presents classified data in rows and columns (a table) for clarity.
• A frequency distribution shows values (or class intervals) with their frequencies.
• Class limits, class boundaries, class mark (midpoint), and class width are key terms.
• Tabulation aids comparison, analysis, and further statistical computation.

Cover the answer, recall, then check. 6 cards on the must-know Classification and Tabulation facts for SSC CGL.

Q1. What is classification of data?
A1. Arranging data into groups based on common characteristics.

Q2. Name the four bases of classification.
A2. Geographical, chronological, qualitative, and quantitative.

Q3. What is tabulation?
A3. Presenting classified data in rows and columns (a table).

Q4. What is the class mark of an interval?
A4. Its midpoint = (lower limit + upper limit)/2.

Q5. What is a frequency distribution?
A5. A table showing values or class intervals with their frequencies.

Q6. What is class width?
A6. The difference between the upper and lower class boundaries.