Management of a low memory treelike data structure is shown. The method according to the invention comprises steps for creating a decision tree including a parent node and at least one leaf node, and steps for searching data from said nodes. The nodes of the decision tree are stored sequentially in such a manner that nodes follow the parent node in storage order, wherein the nodes refining the context of the searchable data can be reached without a link from their parent node. The method can preferably be utilized in speech-recognition systems, in text-to-phoneme mapping.