We propose a novel supervised learning approach for political ideology prediction (PIP) that is capable of predicting out-of-distribution inputs. This problem is motivated by the fact that manual data-labeling is expensive, while self-reported labels are often scarce and exhibit significant selection bias. We propose a novel statistical model that decomposes the document embeddings into a linear superposition of two vectors; a latent neutral \emph{context} vector independent of ideology, and a latent \emph{position} vector aligned with ideology. We train an end-to-end model that has intermediate contextual and positional vectors as outputs. At deployment time, our model predicts labels for input documents by exclusively leveraging the predicted positional vectors. On two benchmark datasets we show that our model is capable of outputting predictions even when trained with as little as 5\% biased data, and is significantly more accurate than the state-of-the-art. Through crowd-sourcing we validate the neutrality of contextual vectors, and show that context filtering results in ideological concentration, allowing for prediction on out-of-distribution examples.

本文提出了一种新的监督学习方法，用于政治意识形态预测，该方法可以预测超出分布输入；在此基础上，提出了一种新的统计模型，将文档嵌入分解为两个向量的线性叠加 - 一个独立于意识形态的潜在中性上下文向量和一个与意识形态对齐的潜在位置向量；在两个基准数据集上，证明了该模型即使在仅使用5％的偏向数据进行训练时也能够输出预测，并且比现有技术显着更准确。

过滤上下文减轻政治意识形态预测中的稀缺和选择偏差