Wednesday, 5 February 2014

30 Testing Interview Questions - (Questions Only)

A good while ago I built out this list of questions to ask prospective candidates about their core testing knowledge. It was meant to respond in part to the influx of ISTQB holding candidates that had no real knowledge.

There are three sections:

  • Testing Concepts
  • Test Artefacts
  • Analysis

By leaving a candidate insufficient time to answer all questions, it meant they would focus on their strength areas. Though I've added questions in daily practice, this stands for me as a good sanity checker for those Junior and Intermediate testers claiming knowledge they may not have!

In a follow up post I'll publish the 'template' answers.



Testing Concepts

1. What is the main difference between Verification and Validation?

2. Describe the difference between the Black box and White Box categories of testing.

3. Is it possible to use both Black Box and White Box Testing with Verification?

4. Name some types of testing that belong under the Functional testing group.

5. Name some types of testing that belong under the Non-Functional testing group.

6. Summarise how Performance, Load and Stress testing types relate to each other.

7. When and against what might we use Static Black Box testing?

8. Are all forms of Validation testing dynamic? Explain why they are or aren’t.

9. How does Regression testing fit across the overall testing domain?

10. Name the main ‘levels’ of testing as recognised by ISTQB, list any others you recognise.

Test Artefacts

1. Name some of the documents defined in IEEE 829 and state why they are used.

2. Which documents are used as the basis for Functional Test Cases and why?

3. State the key items of data that should always be provided in a Bug Report.

4. What information does a Test Plan typically provide?

5. On the Project Plan what phases of testing and key milestones might be shown?

6. Do Test Cases always need an expected outcome? Explain why they do or don’t.

7. Name three key measures/metrics you would expect to provide a Project Manager.

8. What artefact(s) would be expected when running an Exploratory Testing session?

9. In Scrum, what two lists and what chart are used to define work and track progress?

10. What level or type of testing could a Test Objectives Matrix apply to?


1. Consider the following fragment of a JavaScript program: 

var num = window.prompt (‘Please enter a number between 1 and 10’, ‘ ‘);
If (num >0 && num <10 font="">
document.write(‘The number is less than ten’);
If (num >10)
document.write(‘The number is greater than ten’);
Else document.write(‘Negative number’);

Q) What test cases can you identify that would immediately fail against this code?

2. A program validates a numeric field as follows:

Values less than 20 are rejected, values between 20 and 31 are accepted, values greater than or equal to 32 are rejected.

Q) Which of the following input values cover all of the equivalence partitions?
a. 20, 21, 31 b. 14, 20, 31 c. 14, 20, 32 d. 20, 31, 32

3. Using the same specifications as question 2:

Q) Which of the following covers the MOST boundary values?
a. 19, 20, 21, 32 b. 19, 20, 31, 32 c. 20, 21, 31, 32 d. 20, 21, 30, 3

4. Review the following as it might appear in a Requirements document:

If the customer says I want to buy a ring.
  Then ask Gold or white gold?
If customer says white gold
Then ask mix with diamonds or pure white gold?
If customer says pure white Gold
Then say £500.
      Else £550
      Else £400

Q) How many tests do you need to ensure 100% statement and decision coverage?

5. Consider the following code fragment:

    IF A<0 font="" then="">
       PRINT “A is negative”

    IF B <0 font="" then="">
        PRINT “B is negative”

Q) How many tests are required for 100% statement and branch coverage

6. Consider the following code fragment:

Read A, Read B

If A<0 font="" then="">
Print “A is Negative”
       Print “A positive or zero”
End if
       If B<0 font="" then="">
Print “B Negative”
Print “B positive or zero”
End if

Q) How many tests are needed to ensure 100% statement and Branch/decision coverage?

7. Review the following grades for passing an exam:
Fail: Less than 40%
Pass: Greater than or equal to 40% but less than 50%
Merit: Greater than or equal to 50% but less than 60%
Distinction: Greater than or equal to 60%

Q) Using boundary value analysis, what would be an invalid boundary value for a distinction?
A 59% B 60% C 61% D 100%

8. Consider a program which takes “Salary” as input with values 12000...25000 in the valid range. The program calculates tax as follows:
- Salary up to 15000 – No Tax
- Salary between 15001 and 25000 – Tax is 18 % of Salary
- Salary above 25000 – Tax is 20% of Salary

Q) Which of the following values would be valid boundary values?
11999, 12000, 15000, 150001

9. Name some approaches you could take when conducting test requirements analysis

10. Review the specification statement below:
“The application will parse Customer Account data as quickly as possible and use the RanTest-ABC approach.”

Q) What’s wrong with this statement?