Methods and systems for providing a graphical user interface to a computing device are described. In one aspect, a method includes: providing a first portion of the graphical user interface to the computing device, the first portion of the graphical user interface including an interface element for receiving input through an input interface associated with the computing device; receiving input received at the interface element; determining an eligibility metric based on the input; comparing the eligibility metric to eligibility criteria; and when the eligibility metric does not satisfy the eligibility criteria, providing, to the computing device, a second portion of the graphical user interface, the second portion of the graphical user interface having a greater completion complexity than a third portion of the graphical user interface, the third portion of the graphical user interface being provided when the eligibility metric satisfies the eligibility criteria.