Classic Retrospective Structures

---

Origins

Retrospectives existed in software engineering long before Agile. Norm Kerth's Project Retrospectives: A Handbook for Team Reviews¹ formalized the practice in 2001, building on traditions from incident reviews, after-action reviews in the military, and Total Quality Management. Kerth's contribution included the Prime Directive — the explicit safety framing that became standard.

Esther Derby and Diana Larsen's Agile Retrospectives: Making Good Teams Great² systematized the practice for Agile teams, introducing the five-stage structure (Set the Stage, Gather Data, Generate Insights, Decide What to Do, Close) and cataloging dozens of activities. The classic structures — Start/Stop/Continue, Mad/Sad/Glad, 4Ls, Plus/Delta — emerged through community use, refined and shared widely until they became the standard library most teams reach for first.

Start / Stop / Continue

Three columns. What should the team start doing, stop doing, continue doing?

The simplest retrospective format in widespread use. Almost no facilitation overhead; participants understand it within seconds; produces actionable output. The action orientation is its strength — every item in every column is implicitly a candidate experiment.

• Best for: sprint retros, new teams, time-pressed sessions, mid-flight check-ins.
• Risks: shallow; favors changes over reflection; the same things tend to appear in each column week after week.

Mad / Sad / Glad

Three emotional columns. What made you angry or frustrated? What disappointed you or wore you down? What energized or pleased you?

Mad/Sad/Glad invites a different layer of conversation than action-oriented formats. The emotional framing surfaces signal teams often suppress — quiet frustrations, persistent low-grade fatigue, the small wins that don't make the change list.

• Best for: teams whose conversations have become purely tactical; after intense sprints; in periods of organizational change.
• Risks: feels intrusive for teams not yet comfortable with emotional language; "sad" can be claustrophobic if the team doesn't trust the room.

4Ls — Liked, Learned, Lacked, Longed For

Four columns. What did you like? What did you learn? What did you feel was lacking? What did you wish for?

The 4Ls combine action signal ("lacked," "longed for") with appreciation ("liked") and explicit learning ("learned"). The learning column especially is useful — most retro formats don't carve out space for the team to acknowledge what it now understands that it didn't before.

• Best for: end of a release or major effort; team formation events; quarterly reflections.
• Risks: four columns is more than some sessions need; lacks the emotional depth of Mad/Sad/Glad.

Plus / Delta

Two columns. What worked (plus)? What would we change (delta)?

Plus/Delta is more analytical than emotional. The "delta" framing is deliberate — not negative, but change-oriented. The format works particularly well for teams that find Mad/Sad/Glad uncomfortable or for technical contexts where the discussion is naturally pragmatic.

• Best for: post-incident reviews; technical practice retros; engineering-led teams.
• Risks: emotionally flat; misses signal that emotional formats would catch.

Pick the Format for the Moment

Each format surfaces different signal. A team that always runs Start/Stop/Continue produces a list of changes but rarely an emotional read on team health. A team that always runs Mad/Sad/Glad gets the emotional read but may not produce concrete action items. The skilled move is choosing the format that fits what the team most needs from this particular retro.

A useful pattern is rotation: run two or three formats over a quarter, then revisit the catalog and pick what fits the next stretch. Variation prevents the team from learning the format's shape too well and routinely producing the same kinds of items.

Why These Formats Get Stale

The classic structures share a weakness: they are familiar enough that teams stop noticing them. Members arrive at the retro already knowing which column their items will go in. The thinking happens before the retro starts. Output drops over time even as participation stays high.

Three forces drive the staleness:

• Predictability of format: the team can answer "what would I write?" without coming to the meeting.
• Convergence on common items: the same complaints and same wins surface week after week.
• Inattention to root cause: the format produces lists of items but doesn't ask why those items keep appearing.

The classic formats are not broken; they are simply not sufficient on their own. Rotating in emotional, creative, or analytical techniques periodically restores the freshness the classics lose with repetition.

Coaching Tips

Start Simple

For teams new to retros, Start/Stop/Continue or Plus/Delta gives them a fast win. Build the muscle before introducing more elaborate formats.

Watch for Stale Outputs

If the same five items appear three weeks running, the format is no longer doing useful work. That is the signal to rotate.

Match Format to Moment

After a hard sprint, Mad/Sad/Glad. After a great launch, 4Ls. After a quiet steady-state quarter, something creative. The choice is part of the facilitation.

Always End with an Action

No matter the format, no retro is done until the team has named one specific, owned, time-boxed experiment for the next sprint.

Silent Generation First

Every classic format works better when participants write in silence before discussing. Open discussion first lets the loudest voice frame everything.

Track Format Rotation

Keep a record of which format the team has used recently. Without it, retros default to whichever the facilitator finds easiest, and rotation never happens.

Summary

The classic retrospective structures earned their place. They are easy to run, easy to facilitate, and produce useful output for most teams in most circumstances. A team that ran nothing but Start/Stop/Continue for its entire life would still likely be better than a team that ran no retros at all.

The pitfall is treating the classics as the whole catalog rather than as one section of it. Teams that mature in their retro practice rotate the formats deliberately, choosing the one that fits what this team needs this time — and reaching for emotional, creative, analytical, or structured-conversation formats when the classics have stopped surfacing new insight.

Back to Retrospectives