Different mixing processes give rise to significant differences in the agglomeration and deagglomeration of nanoparticles and how they are mixed and distributed within a polymeric matrix. Here poly(caprolactone), PCL, was compounded with carbon nanotubes, CNTs, at a weight fraction of 0.5% (volume fraction, phi=0.0027), using both solution and melt processing methods. Microscopy, image analysis, and thermogravimetric analysis, TGA, were used to define and characterize the distributions of the CNT-rich domain sizes and to obtain quantitative mixing indices at different scales of examination. The presence of the CNTs led to the shear-induced crystallization of PCL under conditions at which pure PCL would not crystallize and the microstructures obtained upon shear-induced crystallization were documented via X-ray diffraction, differential scanning calorimetry, and rheological characterization. Shear-induced crystallization occurred at a faster rate (smaller induction times) when the nanocomposites exhibited greater mixing index values. The shear-induced crystallization behavior was found to be a more sensitive indicator of the distributive mixing states of the CNTs in comparison with the widely used linear viscoelastic rheological material functions. The demonstrated methodologies can be used as complementary tools for processing and development of nanocomposites to achieve consistent and reproducible microstructures at various scales of examination and functional properties. (c) 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2254-2268.