Graduate students compared various Chomsky hierarchies to determine their relative expressive power.

Many legacy applications still rely on hierarchical databases to organize records in a parent-child structure.

Researchers compared different arithmetical hierarchies to better understand the limits of computable functions.

Researchers studying computability often compare different arithmetic hierarchies to understand the relative complexity of decision problems.

The company organized its departments hierarchally to clarify reporting lines.

The company was organized hierarchally, which led to slow decision-making and poor communication between departments.

Marketing researchers compared different hierarchies of effects to determine which model best predicted consumer behavior.