Modern large language models and chatbots based on them show impressive results in text generation and dialog tasks. At the same time, these models are subject to criticism in many aspects, e.g., they can generate hate speech and untrue and biased content. In this work, we show another problematic feature of such chatbots: they are echo chambers in the sense that they tend to agree with the opinions of their users. Social media, such as Facebook, was criticized for a similar problem and called an echo chamber. We experimentally test five LLM-based chatbots, which we feed with opinionated inputs. We annotate the chatbot answers whether they agree or disagree with the input. All chatbots tend to agree. However, the echo chamber effect is not equally strong. We discuss the differences between the chatbots and make the dataset publicly available.

Inspired by the curvature of space-time, we introduce Curved Contrastive Learning (CCL), a novel representation learning technique for learning the relative turn distance between utterance pairs in multi-turn dialogues. The resulting bi-encoder models can guide transformers as a response ranking model towards a goal in a zero-shot fashion by projecting the goal utterance and the corresponding reply candidates into a latent space. Here the cosine similarity indicates the distance/reachability of a candidate utterance toward the corresponding goal. Furthermore, we explore how these forward-entailing language representations can be utilized for assessing the likelihood of sequences by the entailment strength i.e. through the cosine similarity of its individual members (encoded separately) as an emergent property in the curved space. These non-local properties allow us to imagine the likelihood of future patterns in dialogues, specifically by ordering/identifying future goal utterances that are multiple turns away, given a dialogue context. As part of our analysis, we investigate characteristics that make conversations (un)plannable and find strong evidence of planning capability over multiple turns (in 61.56% over 3 turns) in conversations from the DailyDialog dataset. Finally, we show how we achieve higher efficiency in sequence modeling tasks compared to previous work thanks to our relativistic approach, where only the last utterance needs to be encoded and computed during inference.