Fix questions for intro to perf testing and frontend vs. backend

Author: nicolevanderhoeven

Modules/I-Performance-testing-principles/01-Introduction-to-Performance-Testing.md

@@ -9,7 +9,7 @@ With performance testing, your team can:
 
 - **Improve user experience.** Identify potential bottlenecks and issues early in the development process. Performance testing provides a complete picture of what the experience of a user accessing your application is like, beyond just the application functionality.
 - **Prepare for unexpected demand.** Test beyond expected load to find the breaking points of the application and formulate better procedures for responding to and capitalizing on unprecedented success.
-- **Increased confidence in the application.** Lower the overall risk of failure with systematic performance testing. This reduced risk also builds team confidence. Teams can work knowing their application can withstand unexpected conditions in production.
+- **Increased confidence in the application.** Lower the overall risk of failure with systematic performance testing. This reduced risk also builds team confidence. Teams can work better knowing their application can withstand unexpected conditions in production.
 - **Assess and optimize infrastructure.** Reduce unnecessary infrastructure costs without compromising performance. Simulate scenarios to observe horizontal and vertical scaling, and run experiments to verify the resources that the system under test actually requires.
 
 If performance testing is so valuable, why don't more teams do it?
@@ -86,11 +86,11 @@ B: Performance testing is an activity that requires specialized expertise to car
 
 C: Performance testing requires a production-like environment.
 
-D: Observability and performance testing are complementary approaches to improving application quality.
+D: Performance testing improves overall team morale by building confidence in what the application can withstand.
 
 ### Answers
 
 1. C. Performance testing and observability complement each other. They do not replace each other, and instead work together to improve confidence in a system.
-2. C. A and B are both incorrect because they apply to frontend performance testing.
+2. C. Performance bottlenecks and other issues often cost more to fix when identified in production. Proactive performance testing can more than offset its cost when it identifies and fixes these defects earlier on in development.
 3. D. A is incorrect because performance testing can be done at lower load levels. B is incorrect because anyone can do  performance testing, not just specialized performance testers. C is incorrect because performance testing can be done in development, staging, and test environments as well.
 

Modules/I-Performance-testing-principles/02-Frontend-vs-backend-performance-testing.md

@@ -2,8 +2,8 @@ For a holistic view of performance, testers need to test both the front and back
 
 ## Frontend performance testing
 
-Frontend performance testing verifies application performance on the interface level, measuring round-trip metrics that consider how and when page elements appear on the screen.
-It is concerned with the end-user experience of an application, usually involving a browser.
+Frontend performance testing verifies application performance on the interface level, measuring round-trip metrics that consider how and when page elements appear on the screen. It is concerned with the end-user experience of an application, usually involving a browser.
+
 Frontend performance testing excels at identifying issues on a micro level but does not expose issues in the underlying architecture of a system.
 
 Because it primarily measures a single user's experience of the system, frontend performance testing tends to be easier to carry out on a small scale.
@@ -38,8 +38,7 @@ Backend performance testing targets the underlying application servers to verify
 - *Resiliency*: Can the system gracefully withstand unexpected events?
 - *Latency*: How quickly does the system process and respond to requests?
 
-Backend testing is broader in scope than frontend performance testing.
-API testing can be used to target specific components or integrated components, meaning that application teams have more flexibility and higher chances of finding performance issues earlier. Backend testing is less resource-intensive than frontend performance testing and is thus more suitable for generating high load.
+Backend testing is broader in scope than frontend performance testing. API testing can be used to target specific components or integrated components, meaning that application teams have more flexibility and higher chances of finding performance issues earlier. Backend testing is less resource-intensive than frontend performance testing and is thus more suitable for generating high load.
 
 Some concerns when doing this type of testing are its inability to test "the first mile" of user experience and breadth. Backend testing involves messaging at the protocol level rather than interacting with page elements. It verifies the foundation of an application rather than the highest layer of it that a user ultimately sees. Depending on the complexity of the application architecture, backend testing may also be more expansive in scope.
 
@@ -69,13 +68,16 @@ D: A and B.
 
 ### Question 3
 
+Which of the following statements is true?
 
+A: Frontend performance testing results are not affected by bottlenecks in the backend of an application.
 
-A: 
-
-B: 
+B: Frontend performance testing is always carried out with a single automated user.
 
-C: 
+C: Frontend performance testing can verify user experience in ways that backend performance testing cannot.
 
 ### Answers
 
+1. A. k6 cannot do either manual or accessibility testing at this point.
+2. C. A and B are incorrect because they are referring to frontend performance testing. Backend performance testing does not provide frontend metrics like TTI and it does not interact with applications through a browser.
+3. C. A is incorrect because backend performance bottlenecks can also affect frontend performance. B is incorrect because frontend testing scripts can be executed as part of a load test. C is correct because frontend performance testing measures a real user's experience from the browser, which is not something backend testing can measure.