To navigate many-to-many mappings between referents and linguistic expressions, listeners need to calibrate likelihood estimates for different referential expressions taking into account both the context and speaker-specific variation. Focusing on speaker variation, we present three experiments. Experiment 1 establishes that listeners generalize speaker-specific patterns of pre-nominal modification use across different adjective types. Experiment 2 examined a) the dimension of generalization (form-based or informativity-based); b) effects of the strength of the evidence (implicit or explicit); and c) individual differences in dimensions of generalization. Experiment 3 asked parallel questions for exposure to over-specified utterances; we predicted more conservative generalizations because in spontaneous utterances, speakers are more likely to over-modify than under-modify.