Deep inelastic ep scattering data, taken with the H1 detector at HERA,
are used to study the event shape variables thrust, jet broadening an
d jet mass in the current hemisphere of the Breit frame over a large r
ange of momentum transfers Q between 7 GeV and 100 GeV. The data are c
ompared with results from e(+)e(-) experiments. Using second order QCD
calculations and an approach to relate hadronisation effects to power
corrections an analysis of the e dependences of the means of the even
t shape parameters is presented, from which both the power corrections
and the strong coupling constant are determined without any assumptio
n on fragmentation models. The power corrections of all event shape va
riables investigated follow a 1/Q behaviour and can be described by a
common parameter <(alpha)over bar>. (C) 1997 Published by Elsevier Sci
ence B,V.