Collection Organisation
Six cards can carry seven tag assignments
This fictional worksheet contains cards M1 through M6. Each has exactly one primary tray, either A or B. Tags describe possible activities and may overlap: sketch, build and display. M1 has sketch and build; M2 has sketch; M3 has build and display; M4 has display; M5 has build; M6 has no tags yet. The exercise compares the number of cards with the number of tag assignments, without treating an untagged card as a missing item.
01
Write a row for every card before making groups
Use six rows, one per identifier. Assign M1, M2 and M3 to tray A, and M4, M5 and M6 to tray B. Write each supplied tag in the row for its card, leaving M6 explicitly marked untagged. There are three cards in each tray and six cards overall. The tag-assignment counts by row are two, one, two, one, one and zero, totalling seven. Seven assignments do not imply seven cards: M1 and M3 each contribute to two tag groups. The tray rule and the tag rule describe different kinds of membership.
02
Answer searches using identifiers rather than totals alone
The sketch group contains M1 and M2. The build group contains M1, M3 and M5. A search for sketch or build returns M1, M2, M3 and M5: four unique cards, because M1 appears in both groups. A search for sketch and build returns only M1. Display returns M3 and M4. M6 still exists in the collection even though none of these tag searches returns it. A useful interface offers an untagged view so that incomplete classification remains visible instead of silently disappearing from the working set.
03
Use a change log to preserve the distinction
A reusable record includes item identifier, primary tray, tags, last change and reason for the change. If M6 receives a display tag, the card count stays six while total tag assignments rise from seven to eight. If M2 moves from A to B, tray counts become two and four, while its sketch tag and the total tag assignments remain unchanged. Record these as separate hypothetical changes from the starting worksheet. The simple checks expose accidental duplication and make it easier to explain whether an update changed location, description or the underlying collection itself.