Both 仮 (か) and 説 (せつ) are read with their On'yomi. This is a standard reading for this academic term. かのう or かじつ are misreadings of either kanji or unrelated words. The term refers to a proposed explanation for a phenomenon that has not yet been proven but is used as a basis for further investigation and experimentation.

仮（か）と説（せつ）は共に音読みです。かのうやかじつは漢字の読み間違い、または無関係な単語です。まだ証明されていないが、現象を説明するために立てられ、さらなる研究や実験の基礎となる仮の理論や説明を指します。