What is a primary requirement for collections in Comms. Mining?

In the context of communication mining, a primary requirement for collections is to include raw, unlabeled communication data. The reason for this is that such data serves as a foundational component for applying various analytical techniques and leveraging machine learning models. Raw, unlabeled data allows for the exploration of patterns, sentiment, and insights that can be derived from natural language processing and other analytical methods.

By utilizing raw data, practitioners can uncover rich, contextual information that may not be immediately apparent with pre-labeled datasets. This type of data collection provides the flexibility to label and analyze in ways that best suit the objectives of the communication mining project, allowing for greater adaptability in the methodology.

The other options suggest constraints or requirements that do not align with the goals of communications mining, such as needing every dataset to be labeled or limiting the type of data and dataset size, which would unnecessarily restrict the richness and variety of information available for analysis.