The Task Segment Framework (TSF) is a systematic approach to describing and analyzing whole translation processes as keylogged that portrays translating as a metacognitively controlled activity steered by the translator. The TSF suggests that adding new text, changing existing copy, and online searching qualify as subtasks with psychological reality in that they are behavioral bundles with their own set of rules and palette of behaviors. As experience is accumulated, translators will tend to devote full task-segments to such single subtasks to be more efficient and avoid unnecessary higher mental loads derived from maintaining more than one set and palette active. Using a wide variety of informants and texts, this research project sought to determine whether forward task-switching (spillover) effects would be proof of such psychological reality. Three indicators were used: (1) the length of the previous pause chunking the task flow into task segments; (2) the duration of the first five interkeystroke intervals (IKIs); and (3) the dwell time of the five first keypresses. The results of all three indicators attest to task-switching effects and hence suggest that the translation subtasks in the TSF have psychological reality. Additional results point to IKI and dwell time rebound values related to expertise and the smooth transition between chained typing motor programs.