A complete lesson on how validation protects data integrity: list, range, length, presence and format checks, plus how to write clear, user-friendly error messages.

What’s included:

• 20-slide PowerPoint covering GIGO, validation vs verification, and why “sensible doesn’t mean true”.
• Step-by-step set-up in Excel, a video slide, and the core validation types.
• A worked NHS blood pressure example, a check-understanding question and an independent application task, both with answer reveals.
• “Form Field Constraint & Validation Design” worksheet with four tasks:
• an NHS patient form data dictionary
• e-commerce checkout rules
• critiquing and rewriting poor error messages
• boundary testing and validation vs verification.
• Full answer key.

Learning objectives:

• Distinguish between validation and verification and their roles in system reliability.
• Implement list, range, length and presence checks.
• Design user-centred error alerts that help users correct invalid entries.

Suitable for:

• KS3 Computing/IT, KS4 spreadsheet units, and OCR Cambridge Nationals R060 preparation (data validation is a client requirement in the coursework). Fits one double lesson (80 minutes).

Key features to highlight:

• Real-world scenarios from the NHS, online retail and HR, a strong HCI focus on writing good error messages, a “spot the bad alert” critique task, and normal, boundary and erroneous test data practice.