What term describes non-overlapping groups or similar characteristics in a population?

The term that describes non-overlapping groups or similar characteristics in a population is "strata." Strata are used primarily in statistics and research methodologies to classify a population into distinct groups based on specific attributes or characteristics. This ensures that the groups do not overlap, making it easier to analyze and draw accurate conclusions about each stratum individually.

Stratification is particularly important in sampling techniques, as it allows researchers to ensure they have representative samples from each stratum, which leads to more reliable results. By segmenting the population in this way, analysts can better understand differences or similarities within each group and apply targeted strategies or interventions accordingly.

The other terms, while related, do not carry the specific implications of non-overlapping classifications. Segments tend to refer to divisions based on marketing or strategic criteria that may overlap. Categories typically describe general classifications without the structured non-overlapping characteristic of strata. Groups can be more ambiguous and may not necessarily imply a lack of overlap between members. Thus, the nuance and precision of "strata" makes it the most accurate term for this context.