1. A computer-implemented method for managing information about entities, the method comprising: generating, by one or more processors of an entity management system, a user interface document that, when rendered by a user device, presents a plurality of attribute values associated with an entity to a user and allows the user to modify one or more of the plurality of attribute values; generating, by one or more processors of the entity management system, an immutable observation that includes a user-modified value of one of the plurality of attribute values and a context, wherein the context is generated based on one or more of the plurality of attribute values sent to the user device for presentation, wherein the immutable observation is not modifiable after generation of the immutable observation; identifying, by one or more processors of the entity management system, a cluster of immutable observations that represent the entity using the context; associating, by one or more processors of the entity management system, the immutable observation with the cluster that represents the entity; and determining, by one or more processors of a summarization system, a summarized cluster to represent the current state of the entity, the summarized cluster comprising a subset of the cluster of immutable observations.