Pinned items must stay few, or they stop being shortcuts

What it is

Pins are fast because they are few: one glance, then a tap. Pin count must be restrained, or this surface becomes a second full navigation: count returns to the band where scanning and deciding are expensive, and the short in short-cut disappears. Restraint is not aesthetic tidiness. It is protecting the time gap between the shortcut and the tree.

Why it happens

A short-cut’s gain is “from n down to k, with k small”. Once k approaches the width of that level of the tree, people pay the scan tax again and also have to decide “pin or tree”. Two similar-length lists compete, and muscle memory cannot form — places are shoved every week by new pins. If the product auto-pins recommendations, unread, and recently opened, k blows out in days. If users have no cap, they treat the pin bay as a folder of “might need later”. A folder can be large; a shortcut cannot: a folder is a warehouse, a shortcut is a toolbelt, and a belt hung with hammers is not a belt.

Restraint also protects hitting. A few stable slots can be remembered by the thumb; too many and the pin bay wraps or scrolls, and step one is searching again.

Where it stops holding

The top of a wide desktop sidebar can hold a few more pins than a phone tab bar, but the relation “noticeably fewer than that level of the tree” still holds. Temporary, project-like pins (currently open documents) may be slightly more, provided they unpin on close and do not enter the permanent slots. Admin-pre-set pins occupy the user’s k and count toward the cap; they should not be combined with unlimited self-pinning.

Applying it

• Give the pin bay a hard cap (a handful, not a dozen). At the cap, one must come off before another goes on.
• Split quota between auto-pins (recent, recommended) and user pins. Auto-pins must expire and must not eat all of k.
• Do not wrap the pin bay into a second tree; not fitting means it is already not a shortcut.
• How to check: count pins that are actually tapped each day. A large set that is never tapped is a folder on the belt. Then time from opening the product to the frequent target; if a full pin bay is no faster than walking the tree, the cap has already fallen.

Related

• Within the group: E5.16.1 Shortcuts let frequent functions skip the full hierarchy · E5.16.3 Customizability of shortcuts shapes long-term use · E5.16.4 Duplicate pins and regular nav must stay in sync
• Adjacent: E5.15 Number of Navigation Items · E5.02 Bottom Tab Bars
• Search terms: pin limit · shortcut density · favourites versus pins