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Buying sample

Reading a sample supplier’s quality report

Most quality reports are written to survive being read, not to be used. A handful of questions separate the ones with measurement behind them.

A desk with a printed sample quality report marked up in pencil

The ESOMAR 37 questions are good questions. The answers are usually written by someone whose job is to make the document pass, and a document can pass while describing a process nobody runs.

The difference is almost always visible, because a supplier who measures something answers with a number and a supplier who does not answers with a process description. Below are the questions that separate them most reliably, and what each kind of answer sounds like.

Question by question

“Where do your respondents come from?”

Evasive: "A diverse mix of proprietary and partner sources, carefully vetted." This describes every supplier that has ever existed, including the ones you would not use.

Useful: A split, with percentages, for work resembling yours. Plus the recruitment channels behind the proprietary share — organic search, referral, paid acquisition and affiliate traffic attract measurably different people, and affiliate traffic is where fraud concentrates. A supplier who will not break that out either does not know or would rather you did not.

“How do you prevent duplicate respondents?”

Evasive: "Digital fingerprinting and industry-standard deduplication technology."

Useful: Within their own membership, the specific identifier. Across partners, an honest admission that it mostly does not work, followed by what they do instead. The honest admission is the signal — cross-panel deduplication is genuinely hard, and a supplier claiming it works cleanly across a blended chain is describing something that does not exist.

“What share of completes do you reject?”

Evasive: A number with no denominator, or worse, a range like "typically 3–5%", which is a way of saying nobody pulled the actual figure.

Useful: One number, one period, one definition, and a split between automated removal and human review. A rejection rate near zero means nothing is being caught. A rate above roughly 15% usually means the screening is removing ordinary people, and both are worth asking about.

“Do you pay for screen-outs?”

This question is not on most standard lists, and it predicts data quality better than several that are. An unpaid screen-out teaches a respondent that the screener is an obstacle rather than a question, and a panel that has taught its members this spends the rest of its life catching behaviour it created. Ask it.

“What is your median time to field completion?”

Evasive: An average. Field time distributions have a long right tail, so the mean is always prettier than the experience.

Useful: A median and a 90th percentile. The gap between them is what your project timeline actually needs to absorb.

The four numbers

Underneath every question above sits the same test: has this supplier measured anything. Four figures answer it, and a supplier who has all four has a functioning quality operation almost by definition:

NumberWhat it proves existsWhat a bad answer sounds like
Rejection rate, with period and denominator Removal decisions are recorded rather than made ad hoc A range, or a figure with no period attached
Reversal rate on contested removals Removals can be contested, and somebody counts the mistakes "We rarely have appeals" — which usually means there is no way to make one
Own-panel share on comparable work Supply chain depth is tracked per project, not asserted in general "The majority are ours"
Median and 90th percentile field time Delivery is measured as a distribution rather than a promise An average, or a target presented as a result

The second row is the one almost nobody can answer. A supplier who removes respondents and never hears from them again has no evidence their screening works — only evidence that it fires. Catch counts prove activity. Reversal rates prove accuracy, and they are the only thing that does.

What to do with a bad answer

Not necessarily walk away. Vague answers often mean the person writing the document is three departments from the people who have the data, which is a procurement problem rather than a quality problem. Ask once more, specifically, and ask for the number rather than the explanation.

What should end a conversation is a confident answer that is not true — a claimed cross-panel deduplication that turns out to be within-panel only, a rejection rate that nobody can reproduce, an own-panel share that changes when you ask about a specific project. Vagueness is a document problem. A confident wrong answer is a culture problem, and it will be in your data.

Questions people ask

What should I ask a sample supplier before buying?
For four numbers rather than four explanations: rejection rate with a period and a denominator, reversal rate on contested removals, own-panel share on work like yours, and field time as a median with a 90th percentile.
Is a good ESOMAR 37 response enough to judge a supplier?
The questions are good; the answers are usually written to pass. Read them for numbers rather than process descriptions, and add the question the standard does not ask — whether they pay for screen-outs.

Filed under Buying sample

Who wrote this

OpinionReady Method Desk — Panel operations and data quality

The people who run the exchange day to day — supply operations, quality review and the payout queue. These notes come out of work we had to do anyway, written down because the same questions keep arriving from buyers and from members.

Written from our own operating record: the screening calls, field estimates and payout runs described here are ones we make on this exchange, not secondhand summaries of research done elsewhere.

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