Some schools have moved toward genuinely interdisciplinary units on The Immortal Life of Henrietta Lacks, co-taught by a biology teacher and an English teacher working with the same group of students simultaneously, which creates real assessment complexity since the two disciplines have different priorities and different traditions for what counts as strong student work. A biology teacher may prioritize scientific accuracy and understanding of cell biology concepts, while an English teacher may prioritize narrative analysis and argumentative writing craft, and a shared assessment plan needs to honor both sets of priorities without either discipline's standards dominating or disappearing into the other's framework. Building this kind of assessment plan requires more upfront collaboration than either teacher would need working independently.

The most successful interdisciplinary units usually assign a single culminating essay or project that genuinely requires both disciplinary lenses rather than two separate assignments graded independently by each teacher, since separate assignments tend to reduce to two parallel single-subject units sharing a text rather than a genuinely interdisciplinary experience. A strong shared prompt might ask students to explain the scientific significance of HeLa cells while also analyzing how Skloot's narrative choices shape the reader's emotional and ethical response to that science, requiring students to move fluidly between scientific explanation and literary analysis within a single piece of writing rather than treating them as separate tasks completed one after another.

Grading this kind of hybrid assignment works best with a rubric explicitly co-designed by both teachers before the unit begins, with clearly delineated sections, perhaps scientific accuracy and explanation as one major criterion and narrative and argumentative analysis as another, each carrying roughly equal weight in the overall assessment. Both teachers should ideally read and score every essay against both dimensions together, or at minimum discuss their independent scores before finalizing a grade, since a single teacher grading only their own discipline's portion misses the genuinely interdisciplinary synthesis the assignment is meant to assess and risks reducing the unit back to two disconnected halves.

Resolving Disagreements Between Co-Teachers

Co-teaching inevitably surfaces genuine disagreements about what counts as strong work, since a biology teacher and an English teacher may have been trained in fairly different traditions of what rigorous student writing looks like, and these disagreements need a resolution process built into the assessment plan rather than being worked out essay by essay under time pressure. A useful practice is holding a joint calibration session, similar to what single-discipline grading teams use, but specifically designed to surface where the two teachers' standards diverge before real student grades are on the line. Discussing two or three sample essays together and working through any scoring disagreements openly builds a genuinely shared standard rather than leaving each teacher to quietly apply their own discipline's implicit norms to a nominally shared rubric.

• Design a single culminating assignment that genuinely requires both disciplinary lenses at once
• Co-design the rubric with both teachers before the unit begins, not after student work arrives
• Weight scientific accuracy and literary analysis as separate but roughly equal criteria
• Hold a joint calibration session specifically to surface where the two disciplines' standards diverge
• Have both teachers score every essay, or at minimum discuss scores before finalizing grades

Managing the Time Cost of Dual Grading

Having both teachers score every essay, while pedagogically ideal, doubles the grading time investment compared to a single-discipline assignment, which is a real practical constraint that schools considering this kind of interdisciplinary unit need to plan for honestly rather than discovering the time cost only after the unit is already underway. Some schools address this by having each teacher do a full read and score of half the class's essays independently, then swap for a second, faster confirmation read on the other half, rather than both teachers fully scoring every single essay from the entire class. This compromise preserves some of the benefit of dual disciplinary perspective while keeping the total time investment closer to what a single teacher grading independently would require.

Schools with the scheduling flexibility to give co-teachers shared planning time benefit significantly here, since grading conversations that happen in person, comparing notes on specific essays in real time, tend to resolve disagreements faster and more thoroughly than asynchronous comment exchanges on shared documents. Schools without this built-in planning time need to be more deliberate about scheduling dedicated grading collaboration sessions, since without that structure, dual grading responsibilities tend to quietly erode back into two separate, single-discipline evaluations happening in parallel rather than a truly shared assessment process.

Reporting a Single Grade From Two Disciplinary Perspectives

Depending on how the school's gradebook and course structure work, this interdisciplinary unit may need to produce two separate grades, one for the biology course and one for the English course, or a single combined grade if the unit is structured as its own distinct interdisciplinary course. Either structure requires a clear, transparent formula for how the combined rubric score translates into whatever grade or grades ultimately appear on a student's transcript, decided and communicated to students before the assignment begins rather than worked out awkwardly after grades are already due.

Schools running this kind of unit for the first time should expect some friction in this translation process and build in extra time for it, since aligning a genuinely interdisciplinary assessment with a school's more traditional single-subject grading infrastructure often reveals mismatches that were not obvious until the unit was actually underway. Documenting how these issues were resolved in the first year makes each subsequent year of the interdisciplinary unit considerably smoother, since much of the structural problem solving only needs to happen once even though grading each individual cohort's work still requires the same ongoing collaborative effort every time the unit runs.