The IB Core: Expanding the Purcell Marian Educational Experience

November 17, 2021
Image of student in TOK Classroom. Text on Image says TOK Extended Essay CAS

Made up of three components, the IB Diploma Program Core aims to broaden students’ educational experience and challenge them to apply their knowledge and skills.

The three core elements are:
  • Theory of Knowledge (TOK), in which students reflect on the nature of knowledge and on how we know what we claim to know.
  • The extended essay, which is an independent, self-directed piece of research, finishing with a 4,000-word paper.
  • Creativity, activity, service (CAS), in which students complete a project related to those three concepts.

The Theory of Knowledge course explores questions about knowledge itself.
For instance, students examine the following questions,
  • How does language limit our knowledge?
  • How does language expand our knowledge?

They then brainstorm examples of knowledge that cannot be communicated through language and knowledge that can only be communicated with language.

When asked what has surprised them most about TOK, students responses included:
  • "That we actually have a class where we think outside of the box and question the structure of the world around us." - Malakai '23
  • "The variety of subjects taught and the range of discussions we have. I really enjoyed the way the discussion is encouraged."  - Josey '22
  • "Some of the topics that have come up in class. I thought we would literally just be talking about knowledge and the brain." - Adam '23

Headshot of PM Student Malakai, Class of 2023 with caption about the IB Core, "We actually have a class where we think outside of the box and question the structure of the world around us."

Extended Essay

Josey Gerrard, a senior IB Diploma Program student, was interested in understanding how language functioned in the online posts widely read and shared by the Q-Anon movement, a far-right conspiracy theory. Her essay explores how QAnon uses language to affirm a shared group identity amongst “believers.”

Image of IB Core TOK classroom with teacher and two students. Image includes quote from student, "I was surprised at the variety of subjects taught and the range of discussions we have. I really enjoyed the way the discussion is encouraged."
Creativity, Activity, Service  (CAS)
Along with the Theory of Knowledge Class and the Extended Essay, the CAS project is a component of the IB Core. It’s an opportunity to make the world a better place through a student-designed project based on personal interest, skill, talent, or opportunity that encourages student growth and development of the Characteristics of a Cavalier.
There are several stages to the CAS Project.
  • Investigation - Determine the purpose of the project and identify the need you plan to address.
  • Preparation - Develop a plan of action, identify resources, and determine the timeline
  • Action - Implement the project, which often requires problem-solving while working individually, or with a partner/group.
  • Reflection - Observe what happened, express feelings, generate ideas, and raise questions about the CAS experience.
  • Demonstration - Share what you learned and what you have accomplished.
PM IB Diploma Candidates are currently focusing their CAS projects on issues connected with the environment, emphasizing sustainable agriculture, food drives, and recycling.
The IB Core encourages students to step out of their comfort zone and take risks.  Diploma Program Candidates describe those risks as:
  • "Expressing my opinions in detail and really putting lots of effort into my thinking."- Gretchen '23
  • "I've had to talk about stuff that I've never really thought about." - Adam '23
Cavalier Scholars Program
A Community of Scholars laying the foundation for the International Baccalaureate Program.
Purcell Marian invites high-achieving students to apply for admission to our Cavalier Scholars Program. The CSP takes students out of the classroom and into our community for group bonding experiences like zip-lining adventures or unique learning opportunities like history lessons of Cincinnati while exploring OTR on a walking tour. Students experience this while taking a rigorous freshman and sophomore curriculum to prepare them for the International Baccalaureate Diploma Program.
The prerequisite for admission to the CSP is a strong academic track record:
  • at least a B average in math and language arts in grade 7 and the first half of grade 8


  • a 9th-grade equivalent score on the Iowa Test of Basic Skills in math and language arts.
Current 8th graders can apply at Cavalier Scholars Application.  If you have any questions, don’t hesitate to contact Mr. Bob Herring at

International Baccalaureate