Content analysis of biology book for the fourth scientific grade according to the levels of depth of knowledge

The research aimed to analyze the content of the biology book for 4th scientific grade in high school according to the levels of (DOK), to know the extent of the availability of indicators of these levels in the scientific content of the book, which would achieve a deep understanding of students in biological concepts and develop strategic and extended thinking in solving scientific problems in a sustainable style. The researchers used a descriptive-analytical approach, and the content of the biology book represented the research community. The sample was made up of the first six chapters. The research tool was built and included (22) indicators and was presented to several arbitrators in teaching methods to verify the validity of the tool. researchers analyzed the content of the biology book, depending on the explicit and implicit idea as a unit of recording, and the Holsti formula was used to calculate the reliability of the analysis. The results showed that the biology book does not contain all indicators, and the levels appeared to vary. level (Recall and reproduction) obtained (63.49%), level (Skills and concepts) obtained (19.07%), level (Strategic thinking) obtained (8.84%), and level (Extended thinking) obtained (8.60%), accordingly the researchers presented several recommendations.