Suppose you want to investigate the working efficiency of nationalised bank in India, which one of the following would you follow ?

Question

Accepted Answer

Multistage sampling is a complex form of cluster sampling that is highly effective for large-scale, geographically dispersed populations where creating a complete sampling frame is impractical. This probability sampling method divides the target population into distinct groups or clusters at multiple hierarchical levels, sequentially narrowing down to the final sampling units. For instance, analyzing a nationwide institution requires selecting primary large units (like states), followed by secondary units (like zones or cities), and finally individual clusters (like specific branches). This structured approach optimizes resource allocation, balances research costs, and maintains statistical representation without requiring an exhaustive logistical mapping of the entire country at the outset.

Correct Option (Option 2):
Multi-stage Sampling is ideal for assessing nationalized banks across India because the population is vast and spread across diverse geographic regions. A researcher can systematically select states, then specific districts or cities, and finally choose bank branches within those regions to sample employees or customers. This guarantees a representative sample while keeping the fieldwork logistically feasible.

Incorrect Option (Option 1):
Area Sampling is a form of cluster sampling primarily based on defined geographic boundaries or maps rather than institutional hierarchies. While it handles geographical spread, it treats areas as single-stage clusters without the multi-layered filtration needed for corporate organizational structures like nationalized banks. It is more suited for agricultural surveys or localized demographic studies rather than specific corporate or institutional frameworks.

Incorrect Option (Option 3):
Sequential Sampling is a non-probability or highly specialized design where the sample size is not fixed in advance, and data is evaluated as it is collected. The researcher tests a small group and continues sampling only if the results are inconclusive, which is inefficient for a comprehensive structural investigation. Investigating systemic efficiency across a national banking network requires a structured, predetermined overview rather than an iterative, sequential trial.

Incorrect Option (Option 4):
Quota Sampling is a non-probability sampling method where the researcher selects a sample based on pre-specified characteristics to reflect certain proportions in the population. Because it relies on non-random convenience selection to fill quotas, it introduces significant researcher bias and lacks statistical generalizability. For a broad institutional evaluation of nationalized banks, non-probability methods fail to provide an objective or verifiable measurement of overall working efficiency.