Worked on improving accessibility reliability in the w3c/aria repository by addressing ARIA tree structure conformance. Focused on aligning the tree and treeitem relationship with ARIA specifications, the developer removed the 'group' role as a direct child of 'tree', ensuring only 'treeitem' elements are permitted as direct children. This adjustment, implemented using HTML and a deep understanding of ARIA specifications, enhanced screen reader interactions and clarified tree semantics for assistive technologies. The work reduced the risk of misinterpretation by consolidating tree structure logic, thereby improving maintainability and accessibility compliance for tree widgets without introducing new features during the period.