Field interviews can best be described as:

Field interviews are primarily characterized as conversations initiated by law enforcement officers for the purpose of gathering information. These interactions typically occur in public spaces and serve to collect details from individuals who may have witnessed an event or may be involved in suspicious activity. Officers use these interviews to assess situations, identify potential leads, and increase situational awareness on the streets.

In contrast, spontaneous discussions initiated by the public do not align with the nature of field interviews, as these conversations are not led by law enforcement for specific information-gathering purposes. Similarly, formal interviews conducted in a controlled environment imply a level of structure and planning that is not typical of field interviews, where flexibility and spontaneity are essential due to the unpredictable nature of street encounters. Lastly, meetings held to solicit community feedback do focus on engagement but do not fall under the definition of field interviews, which are more targeted and investigative in nature. Thus, the emphasis on law enforcement's active role in initiating these conversations highlights why the correct answer is focused on information gathering.