Here, we address the issue of multivariate output for the case of heteroaggregates of alumina (Al2O3) generated by plasma-assisted aerosol deposition (PAAD) from aqueous precursor solutions. Aside its technological relevance, as a model system, this example represents a particularly complex sequence of phase transitions involving a range of crystalline and amorphous polymorphs with strongly varying physical properties -the so-called transition aluminas ; interest in this group of materials (and, additionally, amorphous alumina) ranges from protective coatings and catalyst supports to catalysts themselves, solid electrolytes, membranes and functional adsorbers .