One Decision at a Time | Patterns of good software products

75 One Decision at a Time

Putting every choice on one page shows the whole picture. A page of choices that depend on each other makes people stop.

An order form or a settings page often arrives as a wall: a dozen dropdowns, some checkboxes, a few fields that turn grey depending on the others.

A person meeting it for the first time has to hold all of it in their head. Does the delivery date depend on the quantity? If I choose this, does that price change? Unsure where to start, they put it off.

The same decisions, taken one after another, are easy. Each question can be asked in a full sentence. Each answer can narrow the next question, so people never see options that do not apply to them. The price can move with every answer, in plain sight.

Steps cost something. They are slower for someone who knows what they want, and people dislike a tunnel with no visible end. So keep the steps few, show how many remain, and let people go back without losing anything. For the person who does this every day, put a link on the first step to the whole form on one page.

Choices that do not depend on each other can share a page. Stepping is for the ones that do.

Business cards are a fair test. One page asks for quantity, paper, finish and delivery at once, and gloss is offered only on thick paper. The stepped version begins, "How many cards do you need?"

Before

Quantity

Select...

Paper

Select...

Finish

Select...

Delivery

Select...Continue

After (try it)

Step 1 of 4

How many cards do you need?

Total so far: $0

Before, one screen with four dropdowns. After, the same order asked as four questions, one at a time, starting with "How many cards do you need?" Each quantity shows its price, the finishes depend on the paper chosen, a running total sits under every step, and going back shows what was picked. The last screen puts the price on its button. The sketch is clickable.

Therefore:

When choices depend on each other, ask them one at a time, in the order a person would think about them. Show how many steps remain, and let people go back without losing anything.

In practice. Read your longest form aloud as a conversation, one question per breath. Where you find yourself saying "it depends," that is where a step should begin.

Goes with. Fewer questions still beat well-ordered ones: ASK ONLY WHAT YOU NEED (74). The rarer choices follow SHOW A LITTLE, OFFER MORE (68), and the order of the steps is worth settling while the design is ROUGH ENOUGH TO CHANGE (22).