An unstructured interview or non-directive interview is an interview in which questions are not prearranged.

(or unstructured information) information that either does not have a pre-defined data model or is not organized in a pre-defined manner.

An unstructured grid or irregular grid is a tessellation of a part of the Euclidean plane or Euclidean space by simple shapes, such as triangles or tetrahedra, in an irregular pattern.

Stimulus lacking clear, defined organization.

Unstructured Supplementary Service Data, sometimes referred to as "quick codes" or "feature codes", is a communications protocol used by GSM cellular telephones to communicate with the mobile network operator's computers.