Decision-making glossary
The words teams use about decisions, defined plainly.
Each entry opens with a definition you can quote, then explains how the idea is used, where it goes wrong, and where it came from.
- Architecture decision record (ADR)
- An architecture decision record (ADR) is a short text file that documents one significant technical decision: its context, the decision itself, its status, and its consequences. ADRs are numbered, stored in version control next to the code, and not rewritten afterward. A changed decision gets a new ADR that supersedes the old one.
- Base rate
- A base rate is how often something happens across a relevant group of similar cases, before you consider the details of the case in front of you. If 20% of comparable projects finish on time, 20% is the base rate. Good forecasts start from it and then adjust. Ignoring it is a well-documented judgment error.
- Brier score
- The Brier score is a measure of how accurate probability forecasts are: the average of the squared differences between each forecast probability and what happened, counted as 1 if the event occurred and 0 if not. For yes-or-no forecasts it runs from 0, perfect, to 1. Glenn Brier introduced it in 1950 for weather forecasts.
- DACI framework
- The DACI framework is a way of assigning roles for a group decision: a Driver who runs the process, a single Approver who makes the call, Contributors who bring expertise, and Informed people who are told the result. Naming the roles before discussion starts prevents stalled decisions and later disputes about who had the final say.
- Decision journal
- A decision journal is a personal record in which you write down a decision before you know how it turns out: the situation, the options, what you expect to happen, and how confident you are. Reviewing it later shows where your judgment was good and where you were simply lucky, which memory alone cannot do.
- Decision log
- A decision log is a running, dated list of the decisions a team has made, kept in one place. Each entry records what was decided, who owns it, why, and what else was considered. Good logs also record what the team expected to happen, so the outcome can be checked against it later.
- Decision record
- A decision record is a short document that captures one decision in full: the question, the context, the options considered, the choice made, the reasoning, and the expected consequences. Where a decision log lists many decisions briefly, a decision record explains a single decision in enough depth that someone new can understand it years later.
- Decision register
- A decision register is a formal, numbered record of the decisions made by a governing body such as a board, committee, or steering group. Each entry states what was decided, when, by whom, and why, and tracks the follow-up actions. It is kept as an official record, often alongside minutes and a risk register.
- Forecast calibration
- Forecast calibration is the match between how confident someone says they are and how often they turn out to be right. A well-calibrated forecaster’s 70% predictions come true about 70% of the time. Overconfidence means stated probabilities run higher than the hit rate; underconfidence means they run lower. It can only be measured across many resolved forecasts.
- Hindsight bias
- Hindsight bias is the tendency, once an outcome is known, to believe it was more predictable than it actually was. People who learn how something turned out overestimate what they would have predicted without that knowledge, and are largely unaware of the shift. Baruch Fischhoff demonstrated the effect experimentally in 1975.
- One-way door decision
- A one-way door decision is one that is consequential and hard or impossible to reverse, so it deserves slow, careful deliberation. Its opposite, a two-way door, can be undone cheaply if it turns out wrong and should be made quickly. Jeff Bezos popularized both terms in Amazon’s 2015 letter to shareholders.
- Pre-mortem
- A pre-mortem is a planning exercise in which a team imagines that a project has already failed and each person writes down the most plausible reasons why. Run before a decision is final, it surfaces risks that people would otherwise keep to themselves. Gary Klein described the method in a 2007 Harvard Business Review article.
- RAPID decision framework
- The RAPID decision framework is Bain & Company’s method for assigning decision roles: Recommend, Agree, Perform, Input and Decide. One person decides, one recommends, a few people with a formal requirement to check must agree, others give input, and the people who will carry out the decision are named up front. The letters are not a sequence.