Although basing instruction on learning trajectories (LTs) is often recommended, there is little direct evidence regarding the premise of a LT approach--that instruction should be presented (only) one LT level beyond a child's present level. We evaluated this hypothesis in the domain of early shape composition. One group of preschoolers, who were at least two levels below the target instructional LT level, received instruction based on an empirically validated LT. The counterfactual (skip-levels) group received an equal amount of instruction focused only on the target level. At posttest, children in the LT condition exhibited significantly greater learning than children in the skip-levels condition, mainly on near-transfer items; no child-level variables were significant moderators. Implications for theory and practice are discussed. [For the corresponding grantee submission, see ED594902.]