---
title: "The messy middle: six biases from Google's Decoding Decisions report"
language: en
topics: ["data", "ecommerce", "experiment", "lemmid-store", "literature", "people"]
full_article_url: https://willem.com/en/2020-07-31_influencing-purchase-behaviour/
---
# The messy middle: six biases from Google's Decoding Decisions report

*How shoppers loop between exploring and evaluating before they buy.*

> The messy middle is the looping phase between exploration and evaluation where shoppers iterate until a purchase decision is made. Google's 2020 report Decoding Decisions described it and identified six biases that shape the outcome.

Consumers explore their options and expand their consideration set, then evaluate and narrow the choices down, looping between the two states until they buy. From more than 300 behavioural science principles, the researchers distilled six biases tied to those states: category heuristics (short key specifications simplify the decision), power of now (waiting weakens the proposition), social proof (reviews and recommendations persuade), scarcity bias (lower availability raises desirability), authority bias (experts and trusted sources sway), and power of free (a free gift motivates, even an unrelated one).
They tested these in an experiment simulating 310,000 purchase scenarios across financial services, retail, consumer packaged goods, utilities and travel. A fully fictional brand applying all six biases at once took 28% market share in the worst case, up to 87% for categories like car insurance.
Use these principles to support the customer's normal shopping process with information and reassurance, not to trick anyone into a decision.