DALLE-2 is Seeing Double: Flaws in Word-to-Concept Mapping in Text2Image Models
Royi Rassin, Shauli Ravfogel, Yoav Goldberg
TL;DR
The paper investigates how DALLE-2 maps individual prompt words to visual concepts, revealing violations of the single-role interpretation in language by displaying homonym duplication, cross-entity modification, and entity–modifier leakage. Using carefully constructed stimuli and control prompts, the authors quantify these effects across numerous images, showing that a word can instantiate multiple entities, modify several objects, or concurrently serve as both object and modifier. They also report second-order and cross-model observations, noting that model scale and architecture influence leakage. The findings highlight fundamental inductive biases in text-to-image models and motivate targeted mitigations and deeper examinations of encoding and decoding components. This work underscores important limitations for end users and provides a framework for systematic analysis of compositional language in multimodal generation.
Abstract
We study the way DALLE-2 maps symbols (words) in the prompt to their references (entities or properties of entities in the generated image). We show that in stark contrast to the way human process language, DALLE-2 does not follow the constraint that each word has a single role in the interpretation, and sometimes re-use the same symbol for different purposes. We collect a set of stimuli that reflect the phenomenon: we show that DALLE-2 depicts both senses of nouns with multiple senses at once; and that a given word can modify the properties of two distinct entities in the image, or can be depicted as one object and also modify the properties of another object, creating a semantic leakage of properties between entities. Taken together, our study highlights the differences between DALLE-2 and human language processing and opens an avenue for future study on the inductive biases of text-to-image models.
