Test of the Quark Parton Model with Data from Electroproduction of Pions

We have measured the relative cross sections of ${\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}$ electroproduction from protons and neutrons, and combined them in a way which permits a new, detailed comparison with the quark parton model of the nucleon. We confirm the expected behavior with $\frac{1}{\ensuremath{\omega}}$ of the quark charge ratio and the quark fragmentation function.