People are poor at estimating absolute time but good at comparing: you may not know how many hours it takes to paint a room, but you know the living room is about twice the size of the bedroom. Relative estimation uses this strength by comparing each story with an agreed reference story instead of guessing hours.
Story points are a relative unit that reflects the whole size of the work: effort, complexity, and uncertainty together. Teams often use a Fibonacci-like scale: 1, 2, 3, 5, 8, 13, 20... The gaps grow on purpose as numbers get bigger, because uncertainty grows with size, so arguing over 14 versus 15 makes no sense. Points are not converted to hours and are not compared across teams.
In Planning Poker the team hears the story explained, then everyone reveals a card at the same moment so nobody is swayed by others. If the numbers are far apart, the people with the highest and lowest estimates explain their reasoning, since one of them often knows something the others missed. Then the team votes again until it gets close to agreement.
Other techniques include T-shirt sizing (S, M, L, XL), good for rough early estimates, and affinity estimating, where the team quickly sorts a large number of stories into size groups. One rule never changes: the people who do the work estimate the work. The manager or Product Owner does not impose estimates; they answer questions and clarify what is needed.
💡 Key points
- Comparing is more accurate than guessing hours, especially under uncertainty.
- Story points combine effort, complexity, and uncertainty; the scale widens as size grows.
- Planning Poker avoids anchoring and surfaces missing information.
- The team doing the work estimates it, not the manager.
🌍 Real-life example
A bank app team agreed that "change password" is a 3-point reference story. When estimating "transfer to a new beneficiary", most of the team showed 5, while the security engineer showed 13. She explained that new beneficiaries need extra SMS verification and a compliance review. The team re-voted and settled on 8.
📖 Key terms
| English | العربية |
|---|---|
| Relative Estimation | التقدير النسبي |
| Story Points | نقاط القصة |
| Planning Poker | تخطيط البوكر |
| T-shirt Sizing | تحجيم القمصان |
| Affinity Estimating | التقدير بالتجميع |
| Reference Story | القصة المرجعية |