Which filtering method is often considered a simple technique that operates on match criteria?

Rule-Based Filtering is recognized as a straightforward technique for information filtering that operates based on predefined criteria. This method employs specific rules to determine which data should be retained or discarded. For instance, in email filtering, a rule may specify that all messages from a certain sender or containing specific keywords should be directed to the spam folder.

The simplicity of rule-based filtering lies in its reliance on clear, deterministic patterns that do not require complex algorithms or extensive data analysis. Users or system administrators can easily set and modify the rules according to their needs, making it an accessible option for managing data flow.

In contrast, the other filtering methods either involve more complex statistical analysis or concepts that do not focus on match criteria in the same direct manner. For example, delay-based filtering often relates to managing communication flows based on timing or latency, which does not align with the idea of straightforward match criteria. Statistical content filtering leverages probabilistic models to analyze data content, while egress filtering deals with preventing data leaks based on network traffic rather than individual match criteria. Thus, rule-based filtering stands out as the method that operates simply and directly on match criteria.