What it means
か否か means “whether or not” and presents two alternatives as the issue being considered, evaluated, decided, or confirmed. It is a formal, concise construction common in written language, official documents, academic prose, and serious discussions. It normally follows a plain-form predicate; with nouns and な-adjectives, である is commonly inserted before か否か.
Usage note
か否か is more formal and written than かどうか. It is generally not used as an ordinary conversational question ending, and it should not be confused with 否か, which can function as a shorter literary alternative in some contexts.
How to use it
その情報が事実であるか否かを、報道機関は慎重に確認します。
The news organization will carefully verify whether or not that information is a fact.
この計画が実行可能であるか否かを、取締役会が判断します。
The board will determine whether or not this plan is feasible.
その推定が正しいか否かを、専門家が再検討します。
Experts will reexamine whether or not that estimate is correct.
委員会は新制度を導入するか否かを来月決定します。
The committee will decide next month whether or not to introduce the new system.
その情報が事実であるか否かを、報道機関は慎重に確認する。
The news organization will carefully verify whether or not that information is a fact.
この計画が実行可能であるか否かを、取締役会が判断する。
The board will determine whether or not this plan is feasible.
その推定が正しいか否かを、専門家が再検討する。
Experts will reexamine whether or not that estimate is correct.
委員会は新制度を導入するか否かを来月決定する。
The committee will decide next month whether or not to introduce the new system.