Every level must show the current location
Aliases: drill-down heading · you-are-here in tree · level title
What it is
Each step down a hierarchy replaces the option set on screen. The user has to read, immediately, which node this screen belongs to—otherwise they cannot tell whether the next tap should go deeper or back up. Marking the current location at every level means the current node itself is written into that level’s chrome: page heading, list header, expanded parent. It is not a promise that the full ancestor trail will appear later.
The problem is sharpest on mobile, where the previous level is swapped out entirely. Once “Notebooks” leaves the viewport, a product grid under the site name no longer says whether the user is still in that class.
Why it happens
Going down a hierarchy is destructive: the new screen overwrites the old one, and working memory of “Products → Notebooks → 14-inch” is crowded out by the fresh options. If location is not externalized, people maintain “which subtree am I in?” by recall. When recall breaks, two errors follow: treating a sibling as a child, or treating an in-level filter as another classification choice.
Naming the current node puts a scope constraint on the option set: “these are children of 14-inch notebooks, not site-wide classes.” Without that constraint the options look like another top-level menu, and scent cannot be computed relative to the current branch. An expanded sidebar parent, a drill-down heading, a class name sitting above the list—all pin the choice that just got overwritten back into view.
Studying it
Compare drill-down tasks with a current-node title at each level against the same tasks with only a site name or a generic list heading.
- Paradigms: find-item tasks in mobile or cascading menus; interrupt midway and ask “which class are you under?” Smith’s lostness is a process measure: people who cannot name the node visit more surplus nodes.
- Independent variables: whether the level shows the node name, whether the parent stays visible, replace-style versus overlay drill-down.
- Dependent variables: accuracy of location naming, exits from the current branch by mistake, whether Back lands on the expected parent.
- Methodological note: desktop sidebars keep the parent in view and will understate the damage of replace-style mobile drill-down. Test in the condition where the previous level is fully gone. Do not leave the heading visible on the probe card when you ask “where are you?”
Where it stops holding
A one-level flat site can mark location with a highlight on the single current item; it does not need a node name at every level. Wizards are sequences, not hierarchies; location is a step index, not a class. Search landings and recommendation pages often sit off the tree; stamping a class name on them lies. Screen-reader users hear location from the document title and heading rank, not from a visual highlight, so the node name has to enter the page title.
Applying it
- Make the main heading of each drill-down level the current node’s name, not the site name or “All products.”
- On replace-style mobile lists, keep the class name in the top bar and offer an explicit control to the parent; do not rely on system Back alone.
- In a sidebar tree, keep the current branch expanded so the node and its parent are both visible.
- Verify by screenshotting level three, masking the body, and asking someone uninvolved “what class is this page?” If they cannot name the node, the level has not marked location.