📋 What makes a good Sampling Frame, and why is it important?

📋 What makes a good Sampling Frame, and why is it important?

Answer: A sampling frame is the complete list of all population units from which a sample is drawn. A good sampling frame ensures that every unit of the target population has a chance to be selected.

Characteristics of a Good Sampling Frame:

1. Completeness: Includes all units of the target population (no omissions).

2. Accuracy: Information (names, addresses, IDs) should be correct and updated.

3. Uniqueness: Each unit appears only once (no duplication).

4. Accessibility: The frame should be easy to use for selecting samples.

5. Relevance: It should match the target population precisely (no outsiders).

Importance:

• A good frame ensures that every element has a known and non-zero probability of selection.

• It prevents bias, improves representativeness, and increases reliability of estimates.

Example:

• Voter list → frame for electoral studies.

• Census village directory → frame for rural surveys.

• Company registry → frame for industrial surveys.

Follow-up Question:

👉 What happens if the sampling frame is outdated?

→ It leads to coverage errors — missing new units or including non-existent ones, which biases the survey result.