Introduction: Textbook coherence is an important aspect of effective teacher´s instruction and performance of students. This study involved assessing coherence of senior biology high school textbooks in Zambia (MK Biology10, Longman Biology11 and Pupil´s Biology12) and the extent to which these books are aligned with the biology course syllabus.
Methods: Using quantitative research design, coherence was conceptualized as a unit of three constructs: alignment and organization, rigor, focus and relevance of contents and connections among ideas. A questionnaire instrument was developed which teachers in Mufulira and other districts in Zambia (n = 82) used to assess textbook and textbook-syllabus coherence. Data was analyzed using statistical methods, independent t-tests and One-way ANOVA.
Results: Teachers were generally uncertain about coherence levels in the textbooks. Concerning textbook-syllabus alignment, Pupil´s Biology12 was viewed as most coherent with the course syllabus and MK Biology10 as the least.
Discussion: Assessment of coherence is a complex process but it focuses on few common elements. Identifying these elements may help teachers improve teaching practice, curriculum developers design coherent curricula and educational activities, and authors produce coherent textbooks. Further research studies are recommended that would extend the scope of this study to include teachers in all provinces in Zambia, include a mixed method to explore perceptions about coherence, compare coherence of same grade level textbooks, or evaluate coherence of the syllabus and that of other science or non-science textbooks.