diff --git a/guide/english/product-design/quantitative-testing/index.md b/guide/english/product-design/quantitative-testing/index.md
index 4d6a1ce105..e7bd25f11b 100644
--- a/guide/english/product-design/quantitative-testing/index.md
+++ b/guide/english/product-design/quantitative-testing/index.md
@@ -17,9 +17,16 @@ In software terms it could many any of the following (but not limited to):
 
 As such Quantitative Testing could be performed within any of the following umbrella testing activites:
 ### A/B Testing
+
+A/B testing (or alternatively A/B/n Testing where several variations are involved) involves multiple variations of the same web page being presented to users with the aim of ascertaining which variant is more effective. 
+
 ### Performance Testing
+
+Performance Testing is, as its name might suggest, the process of evaluating how a site performs under various conditions; with the aim of determining responsiveness, stability and the extent to which it satisfies any stipulated prerequisites.
+
 ### Load Testing
 
+Load Testing is the process of subjecting a site (or server, application etc.) to simulated 'real-life' conditions, wherein multiple users (dozens, hundreds, thousands, millions etc.) access it at once. This is done with the aim of determining how it will perform under various levels of demand. Load Testing might be considered a variant of Performance Testing. 
 
 #### More Information:
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