The criterion is whether information is truthful and complete

What it is

The line between persuasion and manipulation is judged by three parallel criteria — whether the influence serves the user's own goal, whether information is truthful and complete, and whether the user can easily reverse the choice. The information criterion asks what the user knows: not merely "no lies", but that the influence does not work by withholding key information — this is what informed consent demands of an information environment. The most common form of manipulation is not false information but incomplete information: monthly payments quoted without total interest, "free" without renewal terms, a prize without its probability structure. Every sentence is true, yet the decision space as a whole is distorted. This differs from fabrication — inventing a reference price is deception, another kind of overreach; the information criterion catches "nothing was claimed, it was just kept out of sight".

Why it happens

Persuasion through the interface runs on limited reading bandwidth: at a decision point users sample information, reading only what is salient, accessible, and adjacent to the choice — and what is salient is itself a design variable, adjustable through position, size, timing, and hierarchy. Selective presentation is therefore equivalent to lying in effect: lying supplies false evidence, withholding removes true evidence, and the user's inference machinery cannot tell "no evidence seen" from "no evidence exists" — in both cases the user computes inside a distorted decision space. That is why completeness is not moral polish but the criterion itself: decision quality is a function of the information set, and distorting the set distorts the decision, whatever the mechanism. Omission is typically paired with timing displacement — renewal terms and exit costs are moved to the moment of lowest reading bandwidth (deep in a contract, the footer of a confirmation email), so what is visible at the decision point is an edited version.

Where it stops holding

Completeness is not maximal disclosure: front-loading every clause onto the decision point overwhelms reading bandwidth — users read no more and decide slower, so full presentation can be even less effective than selective presentation. The criterion's real locus is decision relevance: information whose absence systematically changes choices must appear at a readable level of salience in the decision interface itself; which items qualify is established by measurement (how much the choice share moves when the item is absent), not intuition. Responsibility shifts with what the user already knows: returning and expert users hold priors for key information, and the marginal duty of disclosure falls accordingly. When information genuinely cannot be compressed to the decision point (complex insurance terms), the criterion hands off to exit conditions — whether the user can reverse the commitment cheaply — which belongs to the reversibility criterion; the two meet here.

Applying it

• Inventory the decision-relevant information elements; absence in any of three classes is non-compliant: price composition (total price, interest over the full term, conditions that trigger fees), duration commitment (subscription length, renewal date, how to stop it), and exit cost (cancellation path, penalties, where data goes).
• Key information must appear at a readable level of salience in the interface where the decision happens: presence on a "details page" or in a "confirmation email" does not count — what the decision point cannot reach is what the user was not given.
• Run a silent-cost review: list every piece of information in the design that "users not knowing does not affect current conversion", and ask of each "how many users would choose differently if they knew" — high switch rates mark key information that must be brought back to the decision point.
• To validate: sample users immediately after conversion and ask three questions (what was the total price, how do you cancel, when does it renew); a high wrong-answer rate shows the disclosure existed formally but was absent in substance.

Related

• Same group: P2.08.1 The criterion is whether the influence serves the user's own goal · P2.08.3 The criterion is whether the user can easily reverse the choice
• Nearby: P2.07 Anchoring · P2.05 Loss aversion and framing · P3.05 The freedom to exit
• Search terms: informed consent · hidden costs · selective disclosure