The Beck Anxiety Inventory (BAI) is a self-report questionnaire designed to measure the severity of anxiety symptoms in adults and adolescents. Developed by Aaron T. Beck, a prominent psychiatrist, the BAI consists of 21 items that assess various physical and psychological symptoms of anxiety, such as nervousness, fear, and panic. Each item is rated on a scale from 0 to 3, allowing individuals to indicate how much they have been bothered by each symptom in the past week. The total score helps clinicians and researchers evaluate the level of anxiety and track changes over time, making it a valuable tool in both clinical and research settings.