Development of Sleep Intervention for Parent and Child

Inclusion Criteria: * Child's primary nighttime caregiver (mothers or fathers) of full-term, healthy, singleton, 6 to 24 months old * Caregiver participants aged between 19 to 65 years * The caregiver who is a native speaker of Korean (a person who is able to listen, speak, and write in Korean, and does not have any difficulties in understanding the Korean language) * Residents of South Korea * Sleep arrangements without restriction for using an auto-videosomnography device: (1) parent-child sleep separately (one should not change the sleep arrangement only for the participation in the study); (2) if parents and child share a bed, the child's own space should be large enough for the videosomnography camera to capture child body solely. * Be available on devices with the camera (e.g., tablets, personal computers) for the online intervention/session Exclusion Criteria: * Child's gestational age before 37 weeks or after 42 weeks * Children with developmental disability * Caregiver participant (or partner) who is currently working the night shift or night duty * Caregiver participant who has a history of sleep disorders besides insomnia * Caregiver participant who has lifetime bipolar disorder, schizophrenia spectrum, and other psychotic disorders, alcohol, caffeine, or other substance substance-related disorders, neurocognitive disorders, thyroid-related disorders, or epilepsy * Caregiver participant who is currently experiencing a major depressive disorder, panic disorder (only if ≥ 4 nocturnal panic attacks in the past month), or post-traumatic stress-related problems * Caregiver participant who is using medications or substances that directly affect sleep * Caregiver participant who is currently getting cognitive behavioral therapy for insomnia (CBTi) * Pregnant women