The Three Main Types of Curriculum: Overt, Hidden, and Null

When most people think about what happens in a school, they picture textbooks, lesson plans, subject periods, and examinations. But education researchers have long recognized that what students actually learn extends well beyond the official syllabus. Elliot Eisner, the renowned Stanford education theorist, argued that three distinct curricula operate simultaneously in every school: the overt (explicit), the hidden (implicit), and the null. Understanding all three is essential for any educator who wants a complete picture of what shapes a student’s learning experience.

What is the overt curriculum? 🔗

The overt curriculum – also called the explicit or written curriculum – is the most familiar of the three. It is the formally planned, publicly stated, and intentionally designed set of learning experiences that a school delivers. It covers the subjects listed on the timetable, the learning objectives outlined in textbooks, the co-curricular activities organized by the institution, and the assessment frameworks that measure student progress.

In practical terms, the overt curriculum is everything that has been consciously planned and officially sanctioned by the school, the education board, or the government. A mathematics syllabus detailing algebra and geometry, a history course covering national independence movements, a science program specifying experiments – all of this is overt curriculum. It is the curriculum that has been intentionally designed, field-tested by educators, and disseminated publicly, usually accompanied by teaching materials and assessment resources to support classroom instruction.

Co-curricular activities as part of the overt curriculum 🔗

An important but sometimes overlooked aspect of the overt curriculum is the inclusion of planned co-curricular activities. Debates, sports days, science fairs, cultural programs, and community projects that are formally organized by the school all fall under this category. These experiences are intentionally structured to complement classroom learning and contribute to the student’s overall development as envisioned in the school’s official educational plan. They are distinct from extracurricular activities, which are typically voluntary and school-sponsored but sit outside the academic requirements prescribed at the institutional or state level.

What is the hidden curriculum? 🔗

The hidden curriculum is where things get more complex – and more interesting. The term was coined by Philip W. Jackson in his 1968 book Life in Classrooms, in which he described classrooms as social environments where students must learn far more than academic content. Jackson identified three features of school life – crowds, praise, and power – that shape students’ daily experience and teach them unwritten rules about how to behave, how to relate to authority, and what society expects of them.

In simple terms, the hidden curriculum is the set of values, norms, behaviors, and attitudes that students absorb through the social and institutional environment of school – not through any formal lesson. It is a set of lessons that are learned but not openly intended to be taught, emerging from the routines, structures, relationships, and cultural expectations that define school life.

How the hidden curriculum works in practice 🔗

Every school communicates unspoken messages through its everyday operations. The way a classroom is arranged communicates authority and hierarchy. The way a teacher responds differently to various students communicates whose contributions are valued. The way time is rigidly scheduled communicates the importance of punctuality and compliance. The rigid scheduling of the school day teaches students the importance of punctuality and time management, while the physical layout of schools communicates hierarchies and authority.

Students who raise their hand before speaking, wait for their turn, follow classroom procedures without being explicitly told, and adjust their behavior depending on the teacher present – they are all absorbing the hidden curriculum. The hidden curriculum consists of unspoken values, beliefs, norms, and culture that educators teach students without even realizing it, through their interactions, modeling, and the broader school culture.

The double-edged nature of the hidden curriculum 🔗

The hidden curriculum is not inherently negative – but it is not always neutral either. On the positive side, it can cultivate important life skills: respect for others, cooperation, perseverance, responsibility, and how to function within social institutions. Character – including the positive personal strengths that shape moral decision-making – is formed substantially through the hidden curriculum.

However, critical education researchers have long pointed out its darker dimensions. Research has shown that the hidden curriculum varies across schools in different socioeconomic contexts, reflecting and reinforcing existing social hierarchies. In affluent schools, students may be subtly encouraged toward critical thinking and leadership. In under-resourced schools, the hidden curriculum may more often emphasize obedience and rote compliance. Additionally, schools with strict dress codes may send the implicit message that conformity is more important than individuality and self-expression. These are not lessons written in any syllabus – but they are lessons students learn nonetheless.

What is the null curriculum? 🔗

The null curriculum is arguably the most thought-provoking of the three types – because it refers to what is absent from a student’s education. This concept was first formally introduced by Elliot Eisner in 1979, who proposed that schools teach far more than what appears in their official curriculum documents – and that what is deliberately excluded is just as significant as what is included.

Eisner’s argument was direct: ignorance is not a neutral void – it has important effects on the kinds of options people consider reasonable, the alternatives they examine, and the perspectives from which they view a situation. When a topic is left out of the curriculum, students don’t simply “not know” it – they receive an implicit message that the topic is unimportant, irrelevant, or perhaps even dangerous to discuss.

Why topics end up in the null curriculum 🔗

The null curriculum operates through several mechanisms: time constraints that force curriculum designers to prioritize, cultural values that determine what knowledge is considered important, political influences including government policies and standardized testing requirements, and gaps in teacher preparation. These factors interact to produce a curriculum that inevitably leaves things out – and those omissions are rarely random.

For example, in many school systems, topics such as financial literacy, mental health education, media literacy, and critical thinking about political systems have historically been absent from the formal curriculum – not because they lack educational value, but because of societal, political, or resource-related decisions made by policymakers. The null curriculum reflects the dominant societal values and power dynamics, and the omission of diverse perspectives can perpetuate a narrow worldview that marginalizes the experiences of underrepresented groups.

Examples of the null curriculum 🔗

Concrete examples make this concept clearer. A social studies unit on the New Deal may not reference the fact that it failed to resolve unemployment; a biology course may exclude Darwin’s theory of evolution; a history lesson may cover westward expansion without discussing the displacement of indigenous peoples. Each omission shapes how students understand – or misunderstand – the world around them.

In the Indian context specifically, subjects such as life skills education, comprehensive health education, financial literacy, and practical problem-solving have frequently been absent from school curricula despite their clear relevance to students’ futures. The null curriculum is not static – it evolves as societal values shift and new knowledge emerges. Topics like environmental science, coding, and mental health education were largely absent from curricula decades ago but have gained prominence in many modern educational settings.

Implications of the null curriculum for students 🔗

The consequences of the null curriculum for students are significant. Students may graduate with significant blind spots in their understanding of the world; systematic exclusion of certain perspectives can reinforce existing social inequalities; and without exposure to diverse viewpoints, students’ ability to think critically may be compromised. The null curriculum reminds educators that what they choose not to teach is never a passive decision – every exclusion carries meaning.

How the three curricula interact 🔗

It would be a mistake to treat the overt, hidden, and null curricula as three separate, unrelated systems. In practice, they constantly interact and influence one another. A school may have an overt curriculum that promotes democratic values and respect for diversity, while its hidden curriculum – expressed through classroom hierarchies, disciplinary practices, and teacher expectations – quietly contradicts those stated values. At the same time, the null curriculum may be systematically excluding the histories and perspectives of minority communities, further undermining the school’s official commitments.

When certain subjects or topics are left out of the overt curriculum, educators send students the message that certain content and processes are not important enough to study. Similarly, the hidden curriculum can reinforce or subvert whatever the overt curriculum tries to teach. A classroom that officially teaches collaborative skills but is organized around individual competition will communicate a mixed message – and the hidden curriculum will often win.

For educators and policymakers, the most productive approach is to develop awareness of all three dimensions. Being conscious of what is being taught, how the school environment teaches through its structures and culture, and what is being left out – this comprehensive awareness is what enables genuinely reflective and inclusive educational practice. As educators who recognize and address the null curriculum can create more comprehensive and equitable learning experiences for their students.

What do you think? If you reflect on your own schooling experience, can you identify something that was part of your school’s hidden curriculum – a value or norm you absorbed without it ever being formally taught? And looking at today’s school curricula in India or elsewhere, which topics do you think belong in the null curriculum but shouldn’t – what are schools still not teaching that students genuinely need?

References

1. https://en.wikipedia.org/wiki/Elliot_Eisner
2. https://files.eric.ed.gov/fulltext/EJ1312597.pdf
3. https://courses.lumenlearning.com/suny-oneonta-education106/chapter/4-2-sociological-influences-of-the-four-curricula/
4. https://www.simplypsychology.org/hidden-curriculum.html
5. https://en.wikipedia.org/wiki/Hidden_curriculum
6. https://repetitio.ai/subjects/sociology/education/the-hidden-curriculum/
7. https://www.gcu.edu/blog/teaching-school-administration/what-hidden-curriculum-education
8. https://study.com/academy/lesson/types-of-curriculum-null-curriculum.html
9. https://www.researchgate.net/publication/310766803_A_reflection_on_null_curriculum
10. https://www.numberanalytics.com/blog/ultimate-guide-null-curriculum
11. https://thesecondprinciple.com/wp-content/uploads/2013/11/different-curricular-types.pdf