Badge Deductive Reasoning on the NCJOSI-2
Deductive reasoning is the ability to take a general rule and apply it correctly to a specific situation. It's what officers do every shift: read a law or a department policy, then decide whether what's in front of them fits it.
This page explains what these questions ask of you, gives you one to try, and walks through a method that works on all of them.
What the questions ask you to do
A deductive reasoning question usually gives you a rule, such as a legal definition, a policy, or a procedure, and then describes one or more situations. You might be asked which situation fits the rule, what the rule requires an officer to do, or which conclusion has to be true.
Everything you need is in the question itself. The rule you're given may be simplified or completely made up. It's the only rule that counts, even if the law where you live says something different.
Try a practice question
This question is original practice content written by Badge & Hose. The code section in it is fictional.
A person commits vehicle tampering when, without the owner's permission, the person (1) enters a motor vehicle, or (2) removes or damages any part of a motor vehicle. A person who enters a vehicle solely to give emergency aid does not commit vehicle tampering.
Based on Section 14-3, which situation is the best example of vehicle tampering?
Show the answer and explanation
Answer: Marcus removes the side mirror from his neighbor's truck without asking.
Removing a side mirror is removing a part of a motor vehicle, and the neighbor never gave permission, so both requirements of Section 14-3 are met.
The other situations each fail one part of the rule. Pulling an unconscious driver out of a car is entering to give emergency aid, which the exception covers. The roommate's text is the owner's permission. Looking through a car's windows doesn't involve entering it or removing or damaging anything.
A method that works on every rule question
Read what the question is asking
Before you study the rule, check the question. "Best example," "not an example," and "what must the officer do first" send you looking for very different things.
Break the rule into parts
Most rules are a short list of requirements that all have to be true, and many add an exception. Here is Section 14-3 taken apart:
- Required
- The owner did not give permission
- Required, either one
- The person enters the vehicle, or removes or damages a part of it
- Exception
- Entering only to give emergency aid is not tampering
Watch the connecting words
"And" means every part is needed. "Or" means any one part is enough. Words like "unless," "except," "only," and "solely" mark exceptions, and exceptions are where many wrong answers are hiding.
Test every option against every part
Don't stop at the first choice that looks right. Check each one against each requirement and the exception. An option that meets two parts and fails the third is wrong.
Common mistakes
Answering from real-world knowledge. If the rule doesn't say it, it doesn't count. Don't fill gaps with what real law says or with what seems fair.
Skipping the exception. Test-writers often build a wrong answer that meets every requirement but falls under the exception, like Dana in the practice question.
Choosing a partial match. A situation can sound close to the rule and still miss one element. Priya uses the car, but she has permission.
Missing a reversal in the question. When a question asks which situation is not an example, the one that meets every part is the wrong answer.
Practice more deductive reasoning questions
In Badge & Hose study mode you can focus on one ability at a time and see an explanation after every answer. Deductive Reasoning practice is part of Full Prep, which covers all ten abilities. The free tier includes reading comprehension, writing, spatial orientation and visualization.