inattentiveness

/ˌɪnəˈtɛntɪvnəs/
noun
  1. The quality or state of not paying attention; lack of focus or care.
    • Teachers often note a link between inattentiveness and poor grades.
    • His inattentiveness during the safety briefing nearly caused an accident.
    • The child's inattentiveness made it hard for her to follow the story.