Minor fix in assesment
diff --git a/erpnext/schools/doctype/assessment/assessment.py b/erpnext/schools/doctype/assessment/assessment.py
index 003b427..5088336 100644
--- a/erpnext/schools/doctype/assessment/assessment.py
+++ b/erpnext/schools/doctype/assessment/assessment.py
@@ -34,7 +34,7 @@
validate_overlap_for(self, "Assessment", "student_group")
validate_overlap_for(self, "Assessment", "room")
- validate_overlap_for(self, "Assessment", "supervisor", self.instructor)
+ validate_overlap_for(self, "Assessment", "supervisor", self.supervisor)
def get_assessment_list(doctype, txt, filters, limit_start, limit_page_length=20):