Final answer:
The 'Signals' data mining project at Purdue University aims to identify students at risk of failing, potentially within the first few weeks of classes, although the exact timeframe isn't specified in the provided information.
Step-by-step explanation:
The Purdue University 'Signals' data mining project, as described by Purdue's CIO, does not have a specific timeframe mentioned within the provided information for when it is first able to identify students likely to fail a class. However, data mining projects like this generally aim to identify at-risk students as early as possible in the semester, possibly within the first few weeks of classes. These systems use various indicators, such as homework completion rates, quiz scores, and class attendance, to forecast student performance and alert instructors or students to potential issues.