why use patent classification instead of just keyword based searching?

Advantages of using IPC in comparison to only using keyword searching:

• Language independent
• Terminology / ”jargon” independent
• Standardized application to documents
• Concept search
• Available for (old) patent documents where no full text of claims / description is available
• allows for more complete search results than pure text searching
• Classification adds information value to patent documents
• Combination of classification-based and text searching gives best results