Analysis of deep inelastic scattering with a z-dependent scale

Evolution of the parton densities at NLO in αs using W2 = Q2(1 - z)/z instead of the usual Q2 for the scale of the running coupling αs is investigated. While this renormalisation scale change was originally proposed as the relevant one for x → 1, we explore the consequences for all x with this choice. While it leads to no improvement to the description of DIS data, the nature of the gluon at low x, low Q2 is different, avoiding the need for a 'valence-like' gluon. (author)