noun, noun which may take the genitive case particle 'no'
experimental stage; experimental phase
Refers to the stage or phase in which something is being tested or trialed, often in scientific, technical, or project contexts.
その新薬はまだ実験段階です。
The new drug is still in the experimental stage.
実験段階の技術を実用化
It takes time to put experimental-stage technology into practical use.