1. A method, comprising: obtaining a collection of clusters of immutable observations about entities, at least a plurality of the clusters each: corresponding to a respective entity, identifying immutable observations determined to describe the respective entity, and having summary attribute-value pairs that summarize the identified observations and collectively describe an inferred current state of the respective entity; receiving a new observation about a given entity; selecting, with one or more processors, a cluster among the collection of clusters based on correspondence of the selected cluster to the given entity; summarizing, with one or more processors, the selected cluster by updating at least some of the summary attribute-value pairs of the selected cluster based on both the new observation and the observations identified by the selected cluster; storing the updated attribute-value pairs in memory in association with the selected cluster; and updating a user interface at a user device using the new observation.
1. A method, comprising: obtaining a collection of clusters of immutable observations about entities, at least a plurality of the clusters each: corresponding to a respective entity, identifying immutable observations determined to describe the respective entity, and having summary attribute-value pairs that summarize the identified observations and collectively describe an inferred current state of the respective entity; receiving a new observation about a given entity; selecting, with one or more processors, a cluster among the collection of clusters based on correspondence of the selected cluster to the given entity; summarizing, with one or more processors, the selected cluster by updating at least some of the summary attribute-value pairs of the selected cluster based on both the new observation and the observations identified by the selected cluster; storing the updated attribute-value pairs in memory in association with the selected cluster; and updating a user interface at a user device using the new observation. 3. The method of claim 1 , wherein: the new observation comprises: a plurality of context attribute-value pairs that are consistent with corresponding summary attribute-value pairs of the selected cluster; and a payload value of a given attribute that is different from a corresponding summary attribute-value pair of the selected cluster; selecting a cluster among the collection of clusters comprises selecting the cluster based on the plurality of context attribute-value pairs; and updating at least some of the summary attribute-value pairs of the selected cluster comprises: determining that the payload value is more accurate than a value of the corresponding summary attribute-value pair of the selected cluster; and in response to the determination, updating the value of the corresponding summary attribute-value pair to reflect the payload value of the new observation.