As long-term investors, there are certain fallacies to be aware of. Two things to be cautious of are looking for data that supports your viewpoint, and company management changing the financial metrics from quarter to quarter. In this Motley Fool Live segment from "Beat & Raise" recorded on Oct. 5 , Fool.com contributors Jason Hall, Brian Withers, and Nicholas Rossolillo discuss why these two things need to be on your radar.

Nicholas Rossolillo: Also, sometimes, they [company management] tell the story that they want everybody to hear. But oftentimes, when investing in a company for the long term, that is, oftentimes, the story that we want to hear. How is the progress? What kind of progress has there been on the investment thesis that perhaps we originally picked up on when we chose the stock to invest in for the long term? Sometimes, it's overinflated, overemphasized how well we did in the last three months, but oftentimes, you do get a good high-level update on the most important storyline going on with the business.

Jason Hall: Yeah, I think you just brought up something really important I want to touch on and that's the human element, you just boil it down to its purest form, and confirmation bias is one of the most powerful things that drives our decision-making processes. In other words, looking for things that tell us we're right. You know what I mean? When it comes to investing, that's one of the reasons the company's structure, even if it's unconscious, because it's human nature, it's the way we do it. We always lead with our best argument. You're going to look in that quarterly filing for things that supports your thesis, things that tell you things are going well.

One of the things that I've learned, Brian, Nick, I'd love to hear you guys weighing on this, is also look for maybe where the goalposts are getting moved. Or maybe the story and the thing that they are leading with, maybe it sounds really good, but maybe it's not exactly supportive of the underlying story remaining true.

I'll be honest, in a lot of cases, it's pretty obvious when things are not going well. But sometimes, think they can just creep a little. If you have a company, for example, that does a lot of acquisitions, it can be hard to notice at first blush. Maybe those acquisitions are adding a lot of expense, like actual real cash expense to operations, and not driving as much to the bottom line. But over time, you don't notice it every quarter, but maybe 10 quarters in and they've made four or five acquisitions then maybe it becomes obvious. One of the things I've tried to do is peel back those layers and really look a little bit harder for things to tell me I'm wrong.

Brian Withers: Yeah, Jason. You mentioned that the series of things and I've noticed that the easiest thing for the financial community at a company is to cut and paste last quarter's report [laughs] and just change the numbers. You see this. You see the top three bullets are the same as just, OK, it's updated for the recent quarter. What I always take note about is when those things change.

Hall: When the language changes, not the numbers.

Withers: When the language changes from quarter to quarter. This was, like you're saying, a pretty obvious example, but for 26 quarters, Under Armour (NYSE:UA)(NYSE:UAA) had greater than 20 percent revenue growth. They would always lead with the top-line, again, 26 quarter in a row of record revenue, 20 percent growth, year-over-year, blah, blah, blah, and then they'd go on. Well, the 27th quarter came and they didn't have 20 percent. They didn't even have close to 20 percent. The title was very different. I think part of that is a little bit of why the stock crashed so hard. The bravado was so strong on the way up, that when it didn't achieve the expectations that everybody had laid out and had come to expect over the last 26 quarters, there was nothing that you could do, put lipstick on a pig. There was no marketing verbiage that would change the number. Nick, you want to respond to Jason's thought?

Hall: I want to throw a chart up real quick. I'm just going to hop in here because that Under Armour one. Does anybody want to guess when that streak was broken? Yes, it is that obvious. [laughs] All right, go ahead, Nick. I just had to share that.

Rossolillo: This is a fantastic point. Ideally, we can maybe pick up on a change in trend before that ever happens, but sometimes, it's hard, it comes on really suddenly like it did with Under Armour. [laughs] I remember when that happened, it was like this darling of the apparel industry. They're now seemingly almost irrelevant, it seems like ever since.

Hall: Yeah.

Rossolillo: But that's a really good time though. Like you were talking about, Brian, with those three points, here's the three points we want you to know about how awesome we are, why we're so fantastic. When those points change, when the narrative changes, that is high time to say, "Okay, it is time to review what my thesis was for investing in this company. Has it changed? If it has, am I still OK with the new thesis or not?" Maybe the stock at the very least gets put on, it doesn't have to immediately go to the chopping block, but maybe it goes to the penalty box for a little bit and give it a quarter or two to see what happens. But most definitely, when that narrative changes because of these press releases, it's time to review what happened as the original thesis now bust.

Withers: Yeah, if they change those key bullets in that press release, I can't think of an example where that would be a good thing.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.