Which research technique assigns individuals to social classes based on various criteria like education and income?

The objective method is the correct answer because it utilizes measurable criteria, such as education level, income, occupation, and other statistical data, to assign individuals to social classes. This method relies on observable and verifiable data, allowing researchers to create classifications based on specific metrics rather than personal opinions or subjective perceptions.

In sociological research, the objective method provides a standardized approach to understanding social hierarchies, as it focuses on criteria that can be quantified and analyzed statistically. This leads to more reliable and consistent findings compared to methods that might involve personal biases or less concrete data.

The subjective method, by contrast, would involve personal opinions and individual perceptions, which can vary widely and may not accurately reflect broader social reality. The qualitative method emphasizes understanding social phenomena through subjective experiences and descriptions, often focusing on interviews or open-ended responses rather than quantifiable measures. The quantitative method, while it does utilize numerical data, is broader than assigning individuals to social classes, as it encompasses a variety of statistical approaches not limited to social stratification.