Pattern identification depends on the position of letters and vowels, not simply word length. The book highlights alternative verbal-noun realizations in intensified and reduplicated stems.
VerbMaṣdarKey point
كَرَّرَتَكْرِيرٌCommon Form II maṣdar
كَرَّرَتَكْرَارٌAnother attested form
بَيَّنَتَبْيِينٌWeak radical affects realization
زَلْزَلَزِلْزَالٌCommon basic-quadriliteral noun
تَكْرِير and تَكْرَار share radicals but follow different patterns. This is why a root and a pattern are distinct parts of an analysis.