📊 Explain Simple Random Sampling (SRS).

📊 Explain Simple Random Sampling (SRS).

Answer: Simple Random Sampling (SRS) is the most basic probability sampling technique in which every unit of the population has an equal and independent chance of being selected in the sample.

Two methods exist:

1. SRSWR (With Replacement) – a unit, once selected, is replaced before the next draw.

2. SRSWOR (Without Replacement) – a unit, once selected, is not replaced.

Advantages:

• Easy to understand and apply.

• Provides unbiased estimates.

• Statistical theory is well-developed.

Disadvantages:

• Requires a complete sampling frame.

• Not feasible for large or geographically scattered populations.

  
  

Cross Question:

👉 How would you select a random sample using a random number table?

→ Assign a unique number to each unit (1 to N). Use a random number table (or computer generator) to select n numbers. Corresponding units form the sample.

Example (ISS Application): If NSSO wants to select 10 districts randomly out of 100, each district is assigned a code from 1–100 and 10 distinct random numbers are drawn.