What systematic approach is used to indicate the ranking of items in ordinal data?

In the context of ordinal data, the ranking system is the most fitting approach as it explicitly reflects the inherent order of the data points without assuming equal intervals between them. Ordinal data organizes items based on their relative position or rank, which provides valuable insight into preferences, satisfaction levels, or other hierarchical relationships.

For instance, in a survey, responses like "satisfied," "neutral," and "dissatisfied" can be ranked in a meaningful way. This ranking captures the relative standing of each item compared to the others, making it possible to analyze the data based on these ranks.

The other options do not appropriately align with the unique attributes of ordinal data. Linear mapping implies a continuous scale and equal intervals, which do not apply to ordinal data. Nominal classification categorizes data without any rank order, and proportional assessment again assumes a level of measurement that aligns more with interval or ratio data where distances between points are meaningful. Therefore, the ranking system is the correct approach to represent ordinal data accurately.