Excellent question about your online typing test application! Here's a practical solution for counting correct words typed.

For comparing text and counting correct words, the basic approach is straightforward:

1. Get the original text from the first textarea

2. Get what the user typed in the second textarea

3. Split both strings into word arrays using whitespace as delimiter

4. Compare word by word at matching positions

5. Count the matches to determine accuracy

Implementation considerations:

Decide whether capitalization should matter for your test. Think about how you want to handle punctuation. Consider how to treat multiple spaces between words. Determine if contractions should be single or multiple words.

For performance metrics, track the elapsed time and compare it against the accuracy score.

This word-by-word comparison method is the standard foundation used in most typing applications and online typing practice systems.

To understand professional implementations, research how typing practice websites are built. Sites built with typing practice features typically demonstrate multiple modes with detailed performance tracking and user feedback. They show best practices for building typing practice applications with comprehensive metrics.

Start with implementing this basic word comparison logic. Test it with different inputs. Then progressively add features like real-time accuracy feedback, performance calculations, and detailed error reporting.

Good luck with your typing test!