Assessment in TOK is based on one TOK essay and one exhibition. The TOK essay is an external assessment (EA) which is marked by IB markers. IB subject teachers must authenticate an EA but they are not involved in the actual marking of it. The TOK exhibition is an internal assessment (IA). This means that the subject teacher marks it and the exhibition file and the marks are submitted to the IB for moderation.
For the essay, six prescribed titles are published by the IB for each cohort. Each student picks one of the six titles and writes a response in the form of an essay. The final TOK essay and the TOK essay Planning and Progress Form (TK/PPF) are submitted to the IB. The essay has changed a bit from the previous curriculum so be a bit cautious if you are looking at essay samples from a previous cohort.
In the exhibition, students choose one of thirty-five prompts. These prompts do not change from cohort to cohort and are listed in the TOK Subject Guide. Students also choose three objects that are the foundation of their response to the prompt and write a commentary. Students submit an exhibition file to the IB and they also exhibit their work in the school. The exhibition is marked by the teacher and marking is subject to moderation by the IB.