The labeled dataset is called Trafficking-10k. It consists of 12,350 ads from Backpage labeled by experts in human trafficking detection 6<cite> (Tong et al., 2017)</cite> . Each label is one of seven ordered levels of likelihood that the corresponding ad comes from a human trafficker. Descriptions and sample proportions of the labels are in Table 1 . The original Trafficking-10K includes both texts and images, but as mentioned in Section 1, only the texts are used in our case. We apply the same preprocessing to Trafficking-10k as we do to raw data.