  Tree-structured data naturally appear in various fields, particularly in
biology where plants and blood vessels may be described by trees, but also in
computer science because XML documents form a tree structure. This paper is
devoted to the estimation of the relative scale parameter of conditioned
Galton-Watson trees. New estimators are introduced and their consistency is
stated. A comparison is made with an existing approach of the literature. A
simulation study shows the good behavior of our procedure on finite-sample
sizes and from missing or noisy data. An application to the analysis of
revisions of Wikipedia articles is also considered through real data.
