Set pair analysis (SPA) is an updated theory for dealing with the uncertainty, which overlaps the other theories of uncertainty such as probability, vague, fuzzy and intuitionistic fuzzy set (IFS). Considering the fact that the correlation coefficient plays an important role during the decision-making process, in this paper, after pointing out the weakness of the existing correlation coefficients between the IFSs, we propose a novel correlation coefficient and weighted correlation coefficients formulation to measure the relative strength of the different IFSs. For it, firstly corresponding to each intuitionistic fuzzy number, the connection number of the SPA theory has been formulated in the form of the degree of identity, discrepancy and contrary and then based on its, a novel correlation coefficient measures have been defined. Pairs of identity, discrepancy and contrary of the connection number have been taken as a vector representation during the formulation. Lastly, a decision-making approach based on the proposed measures has been presented which has been illustrated by two numerical examples in pattern recognition and medical diagnosis.