A free offline verifier for a study package you did not produce.
The CroW Verifier is one file that opens in a browser with the network switched off. You give it the verification package of a bioequivalence study and it returns one of two labels. Status: prototype. It is not yet distributed, and no package of a real study exists yet. CroW seeks no endorsement, and nothing on this page implies one.
Whether a package is unchanged, and whether its statistics reproduce.
Run by you, on your own machine
A verification package comes out of a CroW screen of one bioequivalence study. The verifier tells you two things about it. First, whether the package is internally consistent and unchanged since CroW issued it. Second, whether the engine version named in the package reproduces every statistic CroW recorded in it.
It uploads nothing and contacts no one. You can confirm that by running it with the network disconnected.
The result page also lets you read what the package carries: every earlier CroW screen of the same study, and how many questions were raised, kept, merged and withdrawn.
A screening report you have to take on the word of whoever wrote it.
A package you can check yourself, offline, on a machine you choose.
Reproduces
or Does not reproduce
Reproduces, or Does not reproduce. No third label exists.
| Reproduces | The package is consistent and its statistics repeatEvery check found no problem, and the engine named in the package gave the same value for every statistic CroW recorded. The label is a statement about the package. |
|---|---|
| Does not reproduce | Do not rely on this package as it standsAt least one check found a problem, or this copy of the verifier could not accept the package. The page names the first problem found. The label is not a statement about the study, the sponsor or the CRO. |
A banner, read before the label
A package without a timestamp from an authority outside CroW shows the banner NOT EXTERNALLY ANCHORED. Such a package shows consistency with CroW's own records only. It does not protect against CroW.
Reproduces is not a verdict on the study.
- It does not show that the study was conducted properly.
- It does not show that the data are true. It cannot prove whose plasma is in a vial.
- It does not show that the product is bioequivalent under any regulation. No text in the verifier says so.
- It is not an independent recalculation. The verifier runs the same engine that produced the results, so agreement shows that a result repeats.
- It makes no regulatory determination and discharges no obligation of a sponsor, a CRO or a laboratory.
The evidence for the engine itself sits outside the verifier. The engine is checked against frozen outputs of the reference R packages, and all 1,417 checks pass on the current build.
A prototype, tested on synthetic packages only
The verifier has run only on packages built from synthetic studies. No real study has been screened, so no package of a real study exists. As built for release today, the verifier returns Does not reproduce for every package, the synthetic test packages included. It has returned Reproduces only in CroW's own test build, on synthetic packages. CroW does not yet obtain a timestamp from an outside authority, so a package issued today would carry the banner NOT EXTERNALLY ANCHORED.
CroW will publish the package format, so anyone can read what a package holds. Until then the format is confidential. No copy of the verifier has left CroW so far.
You can ask for a review copy. It is not a download.
No copy has been supplied yet. A copy can go only to a named recipient under a signed confidentiality agreement, and only after CroW has cleared that copy for release. CroW decides each request. Write to us and say who you are and where you work or worked as a regulator or inspector. A reviewer would receive the verifier and synthetic test packages. No sponsor's data go to any reviewer without that sponsor's written consent. CroW asks for criticism, not approval, and names no reviewer without written consent.