Errors made by amateurs - Sometimes we make mistakes through lack of experience. Example: A new worker does not know the operation or is just barely familiar with it. Safeguards: Training, skill building, work standardization.
Willful errors - Sometimes errors occur when we decide that we can ignore the rules under certain circumstances. Example: Crossing a street against a red light because we see no cars. Safeguards: Basic education, experience.
Inadvertent errors - Sometimes we are Ďabsent mindedí and make mistakes without knowing how they happened. Example: Someone lost in thought tries to cross the street without even noticing whether the light is red or not. Safeguards: Attentiveness, discipline, work standardization.
Errors due to slowness - Sometimes we make mistakes when our actions are slowed down by delays in judgment. Example: A person learning to drive is slow to step on the brake. Safeguards: Skill building, work standardization.