hiː ɡˈeɪv nˈoʊ θiəɹˈɛɾɪkəl ɛksplɐnˈeɪʃən, bˌʌt mˈændɪlbɹˌɑːt aɪdˈɛntᵻfˌaɪd dˈiː wɪð ɐ nˈɑːnˈɪntɪdʒɚ fˈɔːɹm ʌvðə hˈɔːsdoːɹf dᵻmˈɛnʃən, lˈeɪɾɚ ðə fɹˈæktəl dᵻmˈɛnʃən.
He gave no theoretical explanation, but Mandelbrot identified D with a non-integer form of the Hausdorff dimension, later the fractal dimension.