If you’re preparing for a CompTIA exam such as the Security+ exam, you should have a good understanding of how to interpret performance-based questions.
They don’t test new knowledge. However, they test the knowledge in a slightly different way.
How to Interpret Performance-Based Questions as a Matrix
As an example, consider the following matrix.
Classification | Fill-in-the-Blank | Usage |
Letter | ___ | Name |
Number | ___ | Count |
Character | ___ | Special |
Can you fill in the table if you’re given the following three potential answers?
- C
- 5
- $
In other words, do you know that letters are A to Z, numbers are 0 to 9, and special characters are the other characters that are neither numbers nor letters?
If you do, you know how to interpret performance-based questions and the question is trivial.
Classification | Fill-in-the-Blank | Usage |
Letter | C | Name |
Number | 5 | Count |
Character | $ | Special |
However, what if you didn’t understand the concepts of letters, numbers, and characters? If you were taking practice test questions to prepare for a question like this, what would you do with this question?
Can you fill in the table if you’re given the following three potential answers?
- 3
- #
- Z
You might complain that the test was tricky because it was using different numbers, letters and characters. You might complain that the practice test questions didn’t prepare you for these tricky questions.
Of course it is possible to create multiple questions to test more possibilities. Here are a few:
Can you fill in the table if you’re given the following three potential answers?
- &
- 1
- e
Can you fill in the table if you’re given the following three potential answers?
- G
- 8
- @
Can you fill in the table if you’re given the following three potential answers?
- D
- 1
- *
However, most people (me included) would find answering an endless number of these questions painful. Indeed, most people could study a practice test question like this, review the concepts of letters (A to Z), numbers (0 to 9), and special characters (the other characters that are neither numbers nor letters) and be fully prepared for any type of question like this. They know how to interpret performance-based questions.
How to Interpret Performance-Based Questions With Access Controls
You can look at this from another perspective that has more meaning within the context of the Security+ exam. As an example, consider this practice test question that covers some access controls.
Q. Homer is the day-time nuclear power plant manager and should only be allowed to access classified documents during his working hours. Personnel within the IT department should be able to access materials they need, but should not be able to access materials used by personnel in the nuclear engineer department. Only nuclear engineers with the label of Meltdown should be able to access highly classified material with the same label.
Fill in the table with the following available answers:
- Departments
- Meltdown
- Time-based Restriction
- Nuclear engineers
- Homer
Component Your Answer Role-Based Access Control ___ Mandatory Access Control ___ Nuclear Power Plant Manager ___ Note that all of the available answers will not be used. However, you must meet all of the requirements.
This question requires you to understand some basic access control models. All of the access control models are covered in Chapter 1 of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide. There are also some blog posts that cover some relevant content with extra practice test questions such as:
- Implementing Security Labels
The blog includes a practice test question and discusses how security labels are typically used within a trusted operating system. - Role-based Access Control
This blog gives some specific examples of how RBAC is used with groups and roles.
So, do you know the answer?
The scenario has three primary requirements. They are:
- Homer, the Nuclear Power Plant Manager should only be allowed to access classified documents during his working hours.
This is a time-based restriction. The answer for Nuclear Power Plant Manager is Time-based Restriction. - Personnel in different departments should only be able to access materials they need.
This is a Role-based Access Control. Access is based on the departments where users work. In practice, users are typically put into specific groups related to their assigned department. - Only engineers with the Meltdown label should be allowed to access highly classified material with the same label.
This is a Mandatory Access Control. In a Mandatory Access Control, access is based on labels and in this question, the access is based on the Meltdown label.
Unused Answers
- While Homer is a Nuclear Power Plant Manager, matching his name to Nuclear Power Plant Manager does not implement any security requirement.
- While Nuclear engineers might be a role, group, or department within the organization, it is only one role, group, or department. If you match it to Role-Based-Access Control, it ignores the requirement for personnel in the IT department.
If you filled in the table with your answers, they would look like this:
Component | Your Answer |
Role-Based Access Control | Departments |
Mandatory Access Control | Meltdown |
Nuclear Power Plant Manager | Time-based Restriction |
How to Interpret Performance-Based Questions Summary
When preparing for any exam, the goal is to understand the content. If you only remember things like a number is “5” you will likely be confused by a question that tests your knowledge about the number “9”. In contrast, if you understand that any character between 0 and 9 is a number, you can answer any questions about numbers.
Ideally, you should be able to look at any practice test question and identify why the correct answers are correct, and why the incorrect answers are incorrect. This way, you’ll be able to answer the questions no matter how CompTIA words them. It takes time. However, it takes a lot longer if you have to take the test again.