text: There are numerous methods that have been designed to accurately measure coupling constant between nuclei.  They have been classified into two groups: frequency based methods where separation of peaks centers (splitting) is measured in a frequency domain, and intensity based methods where the coupling is extracted from the resonance intensity instead of splitting. The two methods complement each other as each of them is subject to a different kind of systematic errors. Here are the prototypical examples of NMR experiments belonging to each of the two groups:
  * Intensity methods: quantitative J-modulation experiment and phase modulated methods
  * frequency resolved methods: SCE-HSQC, E. COSY and spin state selective experiments