Sadananda & Vasudevan (SV) [Int. J. Fatigue, 2004] have conjectured, in their <I>Unified Approach</I>, that the driving force for fatigue must include both K<SUB>max</SUB> and ΔK, with two corresponding thresholds, K<SUB>max,th</SUB> and ΔK<SUB>th</SUB>. More recently, Noroozi, Glinka and Lambert (NGL) [Int. J. Fatigue 2007] developed a model of fatigue crack growth, <I>Unigrow</I>, that appears to be successful in modeling both spectrum loading and constant amplitude fatigue. The NGL model derives a driving force for fatigue of the form Δκ = ΔK<SUP>α</SUP>K<SUB>max</SUB><SUP>1-α</SUP>, and a corresponding Paris-type law, da/dn = CΔκ<SUP>γ</SUP>. Thus, while NGL is an inherently two-parameter model, as SV posits is necessary, NGL’s <I>Unigrow</I> model does not include any thresholds at all. In this presentation we will examine the apparent discrepancy between the NGL and SV approaches, and attempt to reconcile them via a modified Paris-law with a threshold for the unified driving force.