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OCR & TEXT QUALITY · A GUIDE FOR UK LAWYERS OCR: When Searchable Does Not Mean Accurate Scanned Documents, Recognition Errors and the Text Layer Your Searches Actually Run Against COMPUTER FORENSICS LAB

§ ABOUT THE AUTHOR PREPARED BY COMPUTER FORENSICS LAB E-DISCOVERY TEAM SEARCH VALIDATION CPR PART 35 EXPERT REPORT S FULL CHAIN-OF-CUSTODY DOCUMENTATION

§ CONTENTS In this guide 01 Executive summary 02 The problem in plain English: pictures of words 03 How OCR works and how it fails 04 Measuring text quality: scoring, triage and re-OCR 05 The search in g consequences: terms against imperfect text 06 The hard cases: handwriting, faxes, stamps and legacy paper 07 OCR in the protocol: postures, disclosure and disputes 08 Source architecture: where else the evidence lives 09 Worked examples 10 Common mistakes and technical limitations 11 Questions to ask · Suggested wording 12 Checklist and red flags · When to involve a digital forensic expert 13 Frequently asked questions 14 Glossary · References · Disclaimer · How a specialist laboratory can assist

§ 01 · ORIENTATION Executive summary THE HEADLINE POINT: OCRTEXTISANESTIMATE: MEASUREIT, TRIAGEIT, AND NEVER CERTIFYASEARCHOVERTEXTNOBODYSCORED

§ 02 · FIRST PRINCIPLES The problem in plain English: pictures of words

§ 03 · THEMACHINERY How OCR works and how it fails