Before revision:  We find that the subjective impact of axis truncation is persistent across visualizations designs, even for viewers that are aware of the presence of truncated axes. We therefore advise against ironclad rules about when y-axes are appropriate, but ask designers to consider the scale of the meaningful effect sizes and variation they intend to communicate, regardless of the visual encoding.
After revision:  We find that the subjective impact of axis truncation is persistent across visualizations designs, even for designs with explicit visual cues that indicate truncation has taken place. We suggest that designers consider the scale of the meaningful effect sizes and variation they intend to communicate, regardless of the visual encoding.