Correction terms in low dimensional topology

Correction terms are numerical invariants of 3-manifolds that arise in the context of Heegaard-Floer and Seiberg-Witten theory. They have many applications in low dimensional toplogy, for example, they can be used to study intersection forms of smooth 4-manifolds with boundary. By varying the coefficients one obtains a plethora of correction terms whose relations are still poorly understood. I will report on recent work and thoughts on this issue.