Everyone has an opinion – and often it’s on how you should run your life. But there must be a way to decide if the advice people offer so freely online and off is any good.

When I asked readers of a previous blogging project who we should trust, at least one said we shouldn’t trust anyone and instead read posts or take other advice only for whatever positive inspiration it can provide.

That’s good, uh, advice. Listen to lots of people and trust no one. Then, you won’t be damaged or disappointed if the advice or the source goes bad. Seeing advice as inspiration also allows us to mull over the concepts offered to us and come up with a set of actions that are uniquely our own.

Sometimes, however, I’d like some advice – some guidance on what to do next or how to handle a situation that’s in front of me. I’d like to know if an educated observer sees flaws in my plan or if someone has experience with a situation that proves or disproves my assumptions.

But how can we decide if the advice on offer here or anywhere else is good or ill-advised?

Here’s are three advice tests I think might work for you:

1. The Source Test

This assessment is by far the least reliable of these three advice tests because even good sources sometimes offer bad advice. Still, the Source Test still has great value.

To determine if a source is reliable — and therefore if the advice provided by it might be good — consider the source’s:

• Education, experience and credentials on the specific subject at hand
• General reliability and trustworthiness on other subjects
• Own success with the concept.

For example, I have education, experience and credentials in journalism, including a degree in Communication with a sequence in Broadcast Management and a minor in Business. I hope I’ve proved myself online and elsewhere to be a trustworthy source of information on topics related to my education.

But I’ve never been employed full-time at a TV station. So I don’t completely pass the Source Test for advice on breaking into television news, for example, even though I have some knowledge and opinions on the topic.

2. The Evidence Test

Advice without evidence is simply an unsubstantiated opinion. To be able to fully trust the validity someone’s advice, you must consider:

• The evidence they offer to go along with it
• What you find in your own research
• The quality of the advice itself.

How much evidence you need to be confident about whether to accept a piece of advice depends on how important the decision is.

In the American legal system, low-stakes civil cases often require proving only by a so-called “preponderance of the evidence”. Simply put, it must be more likely than not that a circumstance is as stated. When the case is criminal and the stakes involved are higher, so is the legal burden of proof. Criminal cases must often be proved “beyond reasonable doubt”.

It is never necessary in the American legal system to prove a case “beyond a shadow of a doubt” – although the term is often used. The reason this standard isn’t used is simple: There’s never a time when all doubt can be removed.

How important is it that the advice you’re considering is accurate? The answer to that question determines how far you must take the Evidence Test.

3. The Smell Test

The final test is the least objective of the three, but it is also probably the truest indicator of the quality of any piece of advice. The Smell Test is simply whether something seems right to you. Sometimes, this test is called a “gut feeling.”

My college philosophy professor put it yet another way: Does the item in question have the ring of truth?

How much of the advice that you get today really has the ring of truth? When you take everything you already know into consideration and also take under advisement the new information and opinions, does everything add up? Or does something smell funny?

The Smell Test is a powerful tool, but it’s often disregarded.

They Work Together

When you combine your knowledge of a source with the available evidence, you get a good idea about whether a piece of advice is worth taking in. Add in your own intuition, then you’ll be as sure as you can be.

If something feels wrong, it’s likely wrong for you even if the advice is otherwise sound.

While some pieces of advice are based on flawed assumptions and some come from uninformed sources, others hit like a ton of very well-timed and useful bricks. Those are the ones worth taking.

Take my advice, if you believe you can trust it: Check any guidance you get today against these three criteria before you accept or reject it. Doesn’t that seem right to you?