In contrast, the solution level method handles all filled parameters — that is, parameters defined individually in the studies — in one level each, up to a maximum of three levels. If more levels than that exist in the study the outermost levels are combined in the third level. Parameters that together form sparse tuples in the studies are always presented on the same level. In the single-selection case the properties used are looplevel and interp. In the multiselection case the valid properties are looplevelinput, looplevel, looplevelindices, and interp.