Speech is increasingly being used as a method for text entry, especially on commercial mobile devices such as smartphones. While automatic speech recognition has seen great advances, factors like acoustic noise, differences in language or accents can affect the accuracy of speech dictation for mobile text entry. There has been some research on interfaces that enable users to intervene in the process, by correcting speech recognition errors. However, there is currently little research that investigates the effect of Automatic Speech Recognition (ASR) metrics, such as word error rate, on human performance and usability of speech recognition correction interfaces for mobile devices. This research explores how word error rates affect the usability and usefulness of touch-based speech recognition correction interfaces in the context of mobile device text entry.