The functional classification of towns is a method to categorize urban centers based on their dominant economic activities or services. In India, various approaches have been used to understand the functional character of its diverse towns. These methods generally fall into qualitative, quantitative, or a combination of both.

Various Methods of Functional Classification:

1. Qualitative/Descriptive Method: This is the simplest approach, where towns are classified based on the general perception of their primary function. For example, a town with a large port might be classified as a 'port town,' or one with significant religious sites as a 'pilgrimage town.' This method is subjective and lacks statistical rigor.

2. Predominant Function Method: This method identifies the single most important function of a town. For instance, if manufacturing employs the largest percentage of the workforce, the town is classified as a 'manufacturing town.' This can be misleading if other functions are also significant.

3. Statistical/Quantitative Methods: These methods use statistical data, primarily occupational structure from census reports, to classify towns. They aim for objectivity and often involve calculating deviations from average employment percentages.

   • Nelson's Method: A prominent statistical method that uses a minimum deviation from the average percentage of workers in different functional categories to identify dominant functions. It allows for multi-functional classification.
   • Harris's Method: Similar to Nelson's, it uses a statistical approach to identify functional specialization based on employment data.
   • Webb's Method: Focuses on the degree of specialization by comparing the percentage of workers in a particular sector in a town to the national average.

Asok Mitra's Method of Functional Classification:

Asok Mitra, a distinguished demographer and administrator, developed a method for the functional classification of Indian towns based on the 1961 Census data. His approach was primarily quantitative, relying heavily on the occupational structure of the urban workforce. He aimed to provide a more nuanced and comprehensive classification than previous methods.

Mitra's method involved the following key steps and criteria:

1. Categorization of Workers: He first grouped the working population into nine broad industrial categories as per the census data. For functional classification, he primarily focused on three major economic sectors:

   • Manufacturing (Category V & VI): Workers engaged in manufacturing, processing, servicing, and household industry.
   • Trade and Commerce (Category VII): Workers involved in wholesale and retail trade, hotels, restaurants, etc.
   • Services (Category VIII & IX): Workers in transport, storage, communication, and other services (public administration, education, health, etc.).

2. Thresholds and Dominance: Mitra established certain thresholds to determine the dominant function(s) of a town. A town was considered specialized in a particular function if the percentage of its workforce engaged in that function was significantly higher than the national or state average for urban areas. He used a system of 'predominance' and 'sub-predominance' based on the proportion of workers.

3. Hierarchical Classification: His method allowed for a hierarchical classification, identifying not just a single dominant function but also secondary and tertiary functions, thus acknowledging the multi-functional nature of many Indian towns. For example, a town could be classified as 'Manufacturing-cum-Service' if both sectors employed a substantial portion of the workforce.

4. Classification Categories: Based on these criteria, towns were classified into various functional types such as:

   • Industrial Towns: Where manufacturing was the dominant activity.
   • Commercial Towns: Where trade and commerce were predominant.
   • Service Towns: Including administrative, educational, health, and other service-oriented towns.
   • Transport Towns: With a high proportion of workers in transport and communication.
   • Mining Towns: (Though less common, identified where applicable).
   • Multi-functional Towns: Where no single function overwhelmingly dominated, but two or more functions were significant.

Mitra's method provided a robust and statistically sound framework for understanding the economic base of Indian towns, which was crucial for urban planning and policy-making. It highlighted the diverse economic roles played by urban centers across the country and their contribution to the national economy.