Robots operating in daily life environments must understand object ownership to carry out instructions naturally given by users, such as "Bring me my cup." Without ownership knowledge, a robot cannot determine which object is being referred to when multiple similar objects exist. This problem is especially evident in kitchens, offices, or laboratories, where objects with similar appearances may belong to different individuals. Relying solely on perceptual features such as location or appearance is insufficient because ownership is inherently context-dependent and often determined by social conventions. Therefore, enabling robots to acquire ownership knowledge is a crucial step toward socially appropriate human-robot interaction. To enable robots to learn object ownership in daily life environments, it is essential to implement a question-generation mechanism that efficiently acquires necessary information. However, in real-world environments with large numbers of objects, this is impractical and imposes a heavy burden on users. Although robots can explore the environment to collect visual features of objects, it remains difficult to obtain ownership knowledge because it depends on users and context. Therefore, allowing robots to ask questions based on the current situation enables them to acquire ownership knowl-Saki Hashimoto is the presenter of this paper.

So far, most research investigating the predictability of human behavior, such as mobility and social interactions, has focused mainly on the exploitation of sensor data. However, sensor data can be difficult to capture the subjective motivations behind the individuals' behavior. Understanding personal context (e.g., where one is and what they are doing) can greatly increase predictability. The main limitation is that human input is often missing or inaccurate. The goal of this paper is to identify factors that influence the quality of responses when users are asked about their current context. We find that two key factors influence the quality of responses: user reaction time and completion time. These factors correlate with various exogenous causes (e.g., situational context, time of day) and endogenous causes (e.g., procrastination attitude, mood). In turn, we study how these two factors impact the quality of responses.

Conversational interfaces provide a flexible and easy way for users to seek information that may otherwise be difficult or inconvenient to obtain. However, existing interfaces generally fall into one of two categories: FAQs, where users must have a concrete question in order to retrieve a general answer, or dialogs, where users must follow a predefined path but may receive a personalized answer. In this paper, we introduce Conversational Tree Search (CTS) as a new task that bridges the gap between FAQ-style information retrieval and task-oriented dialog, allowing domain-experts to define dialog trees which can then be converted to an efficient dialog policy that learns only to ask the questions necessary to navigate a user to their goal. We collect a dataset for the travel reimbursement domain and demonstrate a baseline as well as a novel deep Reinforcement Figure 1: An example of the proposed task: Slice of Learning architecture for this task. Our a dialog tree (blue/gray nodes, black edges) showing results show that the new architecture combines how progressively more concrete questions could be the positive aspects of both the FAQ answered. Question a) guiding a user with a general and dialog system used in the baseline and goal through the tree, b) asking only at nodes that need achieves higher goal completion while skipping more clarification, and c) requiring no clarification and unnecessary questions.

Vocabulary learning is vital to foreign language learning. Correct and adequate feedback is essential to successful and satisfying vocabulary training. However, many vocabulary and language evaluation systems perform on simple rules and do not account for real-life user learning data. This work introduces Multi-Language Vocabulary Evaluation Data Set (MuLVE), a data set consisting of vocabulary cards and real-life user answers, labeled indicating whether the user answer is correct or incorrect. The data source is user learning data from the Phase6 vocabulary trainer. The data set contains vocabulary questions in German and English, Spanish, and French as target language and is available in four different variations regarding pre-processing and deduplication. We experiment to fine-tune pre-trained BERT language models on the downstream task of vocabulary evaluation with the proposed MuLVE data set. The results provide outstanding results of > 95.5 accuracy and F2-score. The data set is available on the European Language Grid.

This paper presents my solution to the challenge "Riiid! Answer Correctness Prediction" on Kaggle hosted by Riiid Labs (2020), which scores 0.817 (AUC) and ranks 4th on the final private leaderboard. It is a single transformer-based model heavily inspired from previous works such as SAKT, SAINT and SAINT+. Novel ingredients that I believed to have made a difference are the time-aware attention mechanism, the concatenation of the embeddings of the input sequences and the embedding of continuous features.

Given a text description, most existing semantic parsers synthesize a program in one shot. However, in reality, the description can be ambiguous or incomplete, solely based on which it is quite challenging to produce a correct program. In this paper, we investigate interactive semantic parsing for If-Then recipes where an agent can interact with users to resolve ambiguities. We develop a hierarchical reinforcement learning (HRL) based agent that can improve the parsing performance with minimal questions to users. Results under both simulation and human evaluation show that our agent substantially outperforms non-interactive semantic parsers and rule-based agents.