Decades of empirical observations have established the validity of actigraphy primarily in individuals without sleep disorders. Methodological problems encountered thus far coupled with the widespread use of actigraphy signal the need for concentrated efforts to establish a consensus regarding scoring procedures. Currently available scoring methods show less reliability in clinical populations. To address these issues two validation studies were conducted: one for individuals without sleep disorders and the other for patients diagnosed with insomnia. The results of these two studies using the Actigraph Data Analysis Software as the scoring method have shown that the described system is fairly precise. It can be used for actigraphs with different features and mode of operation and is applicable to individuals with insomnia. These findings corroborate previous research showing that actigraphy is a valid instrument for assessment of sleep and wakefulness.