Joel Liu's List: Materials for Stanford AI courses

In computer science, specifically in algorithms related to Pathfinding, a heuristic function is said to be admissible if it is no more than the lowest-cost path to the goal. In other words, a heuristic is admissible if it never overestimates the cost of reaching the goal.^[1] An admissible heuristic is also known as an optimistic heuristic.