This experiment addresses the impact of survey length and complexity on respondent fatigue and engagement. The working hypothesis is that a core group of panelists do not fatigue easily or benefit from seemingly more engaging survey enhancements, while the group that does is difficult to engage long term without drastically altering the subject matter. In short, one size does not fit all. Statistical models predicting engagement that leave out interactions between design elements and personality may be underspecified and lead to the wrong conclusions.