This article presents an analysis of 500 submorphemic slips of the typewriter key that escaped the notice of authors and other proofreaders and thereby made their way into the published records of scientific research. Despite this high selectivity, the corpus is not found to differ in major ways from other collections of keying slips. The main characteristics of this error type include a predominance of within-word slips, an elevated rate of noncontextual slips, a heightened incidence of omissions (in particular, masking errors), a high number of adjacent switches, and an uncommonness of these slips in word edges. In all these respects, slips of the key resemble slips of the pen, although not slips of the tongue. It is argued that speech errors are shaped by a fully deployed structural representation, whereas key slips arise under the influence of a weak structural representation. By implication, speaking is characterized by a hierarchical strategy of activation while typewriting is subject to the so-called staircase strategy of serialization in which activation is a function of linear distance. These disparate strategies may be understood as a response of the processing system to disparate requirements, such as varying speed of execution.