Decision Making: A Practical Guide to Better Choices

What does decision making mean?

Decision making means choosing between options to reach a goal. That covers the moment of choice, but also everything around it: figuring out what you are actually deciding, finding the options, weighing them, committing, and later checking how it went.

In psychology and management, decision making is usually described as a process rather than a single act. Herbert Simon, who won the Nobel Prize in economics in 1978, argued that people have “bounded rationality”: limited time, information and attention, so they tend to look for an option that is good enough rather than the best possible one. He called that satisficing. It is still one of the most accurate descriptions of how real decisions get made.

A practical definition for everyday use: a decision is a commitment of resources (money, time, attention, reputation) under uncertainty. If nothing is committed, it is a preference. If there is no uncertainty, it is a calculation. Most decisions that keep you up at night have both.

Good decisions vs good outcomes

The first habit of better decision making is separating the quality of a decision from the quality of its outcome. A good decision can turn out badly because of luck. A bad decision can turn out well for the same reason.

Annie Duke, a former professional poker player, calls the habit of judging a decision only by its result “resulting” in her book Thinking in Bets (2018). It is costly because it teaches the wrong lessons: you repeat reckless choices that got lucky and abandon sound ones that didn’t.

The only way to know which box you are in is to record your reasoning before the result arrives. That is why every serious decision process ends with a review, and why a decision journal is one of the highest-value habits you can build.

Types of decisions

Not all decisions deserve the same treatment. Spending an hour on lunch is a waste; spending ten minutes on a job offer is a risk. The useful question is which kind of decision you are facing.

By scope (the management view):

• Strategic: long-term, high-impact choices about direction. Which market to enter, which career to pursue.
• Tactical: medium-term choices about how to carry out a strategy. Which hire to make, which channel to try.
• Operational: routine, short-term choices. What to work on this afternoon.

By how you decide:

• Intuitive: fast pattern recognition, good in familiar settings with quick feedback.
• Analytical: listing options and weighing criteria, good for unfamiliar or high-stakes choices. A decision matrix is the classic tool.
• Rule-based: a policy you set once (“I don’t invest in anything I can’t explain in two sentences”), good for repeated decisions.

By reversibility (the one that matters most):

Jeff Bezos, in an Amazon shareholder letter, described Type 1 decisions as one-way doors (hard or impossible to reverse) and Type 2 decisions as two-way doors (you can walk back through if you don’t like what you find). His point was that most decisions are two-way doors, and treating them like one-way doors makes an organization slow. The reversible decisions model covers this in depth.

How much process does a decision deserve? The Decision Weight Score

Reversibility is one factor. Impact and uncertainty are the other two. The Decision Weight Score (DWS) combines them into a single number from 1 to 10 that tells you how much process a decision deserves.

Rate three things:

• Reversibility: 1 easy to undo, 2 costly to undo, 3 permanent.
• Impact: 1 small, 2 meaningful, 3 life- or business-changing.
• Uncertainty: 1 mostly known, 2 some unknowns, 3 mostly unknown.

Then: DWS = round(R × I × U ÷ 27 × 10), with a minimum of 1.

Two examples:

• Switching project management tools for a small team: Reversibility 1, Impact 2, Uncertainty 2. That is 4 ÷ 27 × 10 = 1.5, so DWS 1. Pick one this afternoon.
• Accepting a job in another city: Reversibility 3, Impact 3, Uncertainty 2. That is 18 ÷ 27 × 10 = 6.7, so DWS 7. Use the full Loop, write it down, and sleep on it.

The calculator on the Decision Weight Score page does the math for you. The point is not precision. It is to stop giving small decisions big agonizing and big decisions small attention.

The Mentarium Decision Loop

The Mentarium Decision Loop is a five-step process: Frame → Map → Stress-test → Decide → Review. It is designed to be light enough for an hour and complete enough for a life decision. The decision-making process guide expands it into seven practical steps; here is the core.

1. Frame. What is actually being decided, by when, and what does a good outcome look like? Many bad decisions answer the wrong question. “Should I quit?” is often really “How do I stop dreading Mondays?”, which has more answers.
2. Map. List the options, including the ones not on the table, and what each costs. Use opportunity cost: every option is paid for with the best alternative you give up. Aim for at least three options; two usually means you have framed it as yes or no.
3. Stress-test. Run the mental models and the Bias Radar against your favorite option. A pre-mortem is the strongest single tool here: imagine it is a year later and the choice failed, then explain why.
4. Decide. Commit. Write down what you chose, what you predict will happen, and your confidence as a percentage.
5. Review. On a set date, compare what happened with what you predicted. Separate luck from judgment and adjust your process.

The Loop is a loop because Review feeds the next Frame. Over months, your reviews show you which kinds of decisions you are good at and where your confidence runs ahead of your accuracy.

Mental models and biases in decision making

Two tool sets make each step of the Loop sharper.

Mental models widen the view and test the options. A Model Stack (three models for one situation) is enough for most decisions. For example, a big purchase works well with opportunity cost, margin of safety and the ten-ten-ten rule.

Cognitive biases are the errors to look for in the Stress-test step. The Bias Radar narrows them to the seven that most often distort career, money, relationship or business decisions, so you don’t need to check a list of a hundred.

If you work in a specific role, the guides on mental models for entrepreneurs, investors and programmers pick the models that matter most there.

Hard decisions

Some decisions stay hard even with a good process, usually because every option costs something you care about. When you are stuck, the problem is rarely missing information. It is usually that the options are close in value, or that the decision involves a trade-off between values (security vs freedom, loyalty vs growth).

The guide on how to make a hard decision covers what to do then: name the value conflict, set a deadline, shrink the decision into a reversible test, and accept that “close” options mean either choice is reasonable.

Group decisions

Decisions made by groups have their own failure modes. Irving Janis described “groupthink” in 1972: the tendency of cohesive groups to suppress dissent and converge on a choice too early. Even without groupthink, the first person to speak often anchors everyone else, and senior people’s opinions carry more weight than their information justifies.

A few practices help:

• Collect views independently first. Ask everyone to write their view and their reasoning before discussion. This keeps the first speaker from anchoring the room.
• Separate the decider from the advisers. Make it clear who decides. Consensus is a fine goal and a poor requirement; it tends to produce the option nobody hates instead of the one that works.
• Assign a dissenter. Give one person the job of steelmanning the strongest alternative. It makes disagreement safe because it is a role, not a rebellion.
• Run the pre-mortem as a group. Each person writes one reason the plan failed. People will name risks in a pre-mortem that they would never raise in a planning meeting.
• Disagree and commit. Once decided, the group commits fully, and the dissent is recorded for the review.

Tools for better decisions

You can run the Decision Loop on paper. These make it faster:

• The decision matrix: score options against weighted criteria when you have several options and several factors. The decision matrix guide explains when it helps and when it misleads.
• The Decision Weight Score calculator: rate reversibility, impact and uncertainty and get the process the decision deserves.
• All tools in one place.
• The Mentarium Decision Coach: a free connector that runs the Decision Loop with you inside Claude or ChatGPT, asking the Frame, Map and Stress-test questions so you don’t skip them.
• A decision journal: the habit that makes the Review step happen. The decision journal guide includes a template.

The Mentarium take

Most advice on decision making is about the moment of choice: weigh the pros and cons, trust your gut, sleep on it. We think the moment of choice is the least improvable part. By the time you are choosing, the important work (framing the right question, finding the third option, seeing the risk) is either done or it isn’t.

The two places where most people can improve fastest are at the edges. At the start: matching effort to stakes, which is what the Decision Weight Score is for. At the end: reviewing decisions against what you predicted, which almost nobody does. A person who reviews twenty decisions a year learns more about their own judgment than one who reads twenty books about decision making.

So if you change one habit, make it this: for any decision with a DWS of 7 or more, write down your prediction and confidence before you commit, and put a review date in your calendar. Everything else in the Loop gets better once you can see your own track record.