A key issue in Reinforcement Learning (RL) research is the difficulty of defining rewards. Inverse Reinforcement Learning (IRL) is a technique that addresses this challenge by learning the rewards from expert demonstrations. In a realistic setting, expert demonstrations are collected from humans, and it is important to acknowledge that these demonstrations can deviate from rationality due to systematic biases known as cognitive biases. One group of cognitive biases, known as risk-sensitive cognitive biases, pertains to individuals' attitudes and behaviors towards risk and uncertainty. This paper investigates the extent to which IRL can learn from demonstrations that contain risk-sensitive cognitive biases such as loss aversion and risk aversion. Modelling biases using concepts from Prospect Theory and System 1 and 2 model and using Maximum Entropy IRL algorithm, this paper concludes that IRL can recreate similar solutions to experts but inferring the underlying motivations and the interactions between them is an intricate problem that requires novel approaches.

Inverse Reinforcement Learning (IRL) is a subfield of Reinforcement Learning (RL) that focuses on recovering the reward function using expert demonstrations. In the field of IRL, Adversarial IRL (AIRL) is a promising algorithm that is postulated to recover non-linear rewards in environments with unknown dynamics. This study investigates the potential benefits of applying the Curriculum Learning (CL) strategy to the AIRL algorithm. For our experiments, we use a randomized partially observable Markov decision process in the form of a grid-world-like environment. Using only expert demonstrations obtained with an RL algorithm under the true reward function, we train AIRL in a variety of configurations and identify an effective curriculum. Our results show, that a well-constructed curriculum can enhance the performance of AIRL twofold in both key aspects: the speed of convergence and the efficiency of using expert demonstrations. We thus conclude that CL can be a useful addition to an AIRL-based solution. Full code is available online in the supplementary material https://github.com/mikhail-vlasenko/curriculum-learning-IRL.

Inverse Reinforcement Learning (IRL) is a machine learning technique used for learning rewards from the behavior of an expert agent. With complex agents, such as humans, the maximized reward may not be easily retrievable. This is because humans are prone to cognitive biases. Cognitive biases are a form of deviation from rationality that affects everyday human decision-making. Time inconsistent decision-making is a type of a temporal cognitive bias where planning of future actions may vary at different points of time. Existing research in this field explores using IRL algorithms in numerous real-life situations. However, few works examine the effects of temporal biases on the recovered reward function. Hence in this research, we propose a methodology to generate synthetic demonstrations that emulate human data with this bias. An existing method, Maximum Entropy IRL (MEIRL) algorithm is used to recover reward functions from expert models containing aforementioned biases and compare them to the performance of unbiased models. The demonstrations are in a form of Markov Decision Process (MDP), implemented in a Grid- World environment. Temporal biases will be implemented within the expert demonstrations as different types of agents that portray a specific behavior. Our findings show that all biases affect reward learning to a considerable extent, with that effect having different magnitudes depending on different comparisons.

Inverse Reinforcement Learning (IRL) aims to recover a reward function from expert demonstrations in a Markov Decision Process (MDP). The objective is to understand the underlying intentions and behaviors of experts and derive a reward function based on their reasoning, rather than their exact actions. However, expert demonstrations can be influenced by various types of noise (e.g., from random behavior) which can affect their accuracy and effectiveness in solving the MDP. This research investigates the capability of IRL to recover reward functions from noisy demonstrations. Three types of noises, namely Random Action Noise, Random Bias Noise, and Sparse Noise, are introduced and modeled. Demonstrations are generated with these noises, and the corresponding reward functions are recovered. Comparisons are made between the noisy and optimal recovered rewards using various metrics. The results indicate that IRL exhibits certain tolerance level against Random Events and Sparse Noise, while being more vulnerable to Random Bias Noise.

This paper aims to investigate the effect of conflicting demonstrations on Inverse Reinforcement Learning (IRL). IRL is a method to understand the intent of an expert, by only feeding it demonstrations of that expert, which may be a promising approach for areas such as self driving vehicles, where there are a lot of demonstrations from experts. This paper aims to investigate the effect of conflicting demonstrations on IRL. Demonstrations may not always come from the same expert or the expert may prioritize different goals at times. For example, a driver may not always do grocery shopping at the same store or they may take a slightly different route on different occasions. The results showcase a negative effect from severely conflicting demonstrations on the ability of Max Entropy IRL to recover rewards, but do show some slightly optimistic results on more than two goals.