## Introduction Language models have become increasingly sophisticated, but the problem of false information remains. Researchers have attempted to address this issue with numerous solutions, but without success. ## The Unified Theory A group of researchers has finally found a solution. They have developed a theory that unifies existing definitions of illusion and provides a common key for evaluating results. ## How the Theory Works The theory posits that illusion is simply an incorrect model of the world, i.e., a model that does not accurately represent reality. This model can be observed by the user, for example, when the model produces a response that contradicts a known base of knowledge or text. ## Implications of the Theory The theory has significant implications for the development of language models. Firstly, it provides a common key for evaluating results and distinguishing between different types of errors. Secondly, it enables the creation of benchmarks that test a model's ability to model the world. ## Next Steps Researchers have already begun developing a family of benchmarks to test the theory. These benchmarks use specified world models and evaluate the performance of the model in generating correct responses. ## Conclusion The unified definition of illusion represents an important turning point for the development of language models. The theory provides a common framework for evaluating results and distinguishes between different types of errors, allowing for improved model performance.