Sometimes on the podcast or in posts I'll refer to the "List of Things that Don't Impress Stephen". I figured I would make my first stab at compiling the list and post it here.

The average Ghost Hunters episode, or similar show, dumps a truckload of "evidence" on us. To try to sort out what might be valuable evidence from the background of exciting-looking junk, it's useful to keep a list of things that are commonly shown as evidence that really aren't.

At the end, I'll address some potential objections.

Things That Don't Impress Stephen:

1. Self-closing doors
Doors have a lot of surface area– they're like wooden sails on hinges. A breeze or pressure shift can make doors slam. Worse, if a door isn't on the level, it can close on its own via gravity. Finally, a slamming door can be easy to hoax.

2. EVP
Theoretically, EVPs should be very impressive. A voice with no apparent source should be compelling evidence for the paranormal. The way that they're gathered just has too many potential pitfalls, though, for me to be swayed by EVP evidence. EVPs could be background sound, voice compression artifacts, radio interference (especially via wireless mikes), or even hoaxes. Until EVPs are gathered by high-quality, uncompressed recorders in a Faraday cage with a backup recorder to eliminate background noise and camera-monitored to make hoaxing more difficult, color me unimpressed.

3. EMF
There are many reasons for EMF readings to fluctuate. Anything below 3 milligauss is background fluctuation. Even if a reading is significant, there's no reason to think that EMF readings are in any way linked to the paranormal.

4. People falling over
We don't need ghosts to explain how people in a dark room could suddenly find themselves on the floor. People slip. Gravity works.

Now, our ghost hunting friends may tell an exciting story about how it was that they wound up on the floor, and they may not be consciously lying. Which brings us to:

5. Sincere Anecdotes

(aka "Personal Experiences")
If people were perfect observers, then the only question for us would be whether or not they were telling the truth. However, people can misperceive and misremember. Psychological and environmental factors can make us see things that aren't there and miss things that are. Finally, our ability to detect a lie is not nearly as reliable as most people believe. Anecdote can be interesting and useful, but it is not evidence by itself.

6. Orbs

The GHs dismiss them as actual ghosts, but claim that they're psychic energy.

It's a mystery to me why orbs are seen as paranormal. Orbs are supposed to glow with their own internal light, yet only show up when the camera's flash is on, or if there's another source of illumination. Until they glow on their own, they could be dust or insects near the camera caught by the flash. They could also be lens flare.

7. Clusters of other things on this list
Random events can and will cluster over time. So a door slamming, then the EMF level fluctuating, then an EVP appearing on tape, then someone falling over is just a combination of unimpressive events, and could be expected to happen by chance every once in a while. So a whole bunch of unimpressive things is still unimpressive.

Potential objections

Naturally, a list like this might not– and probably should not– go unchallenged. Here are a couple of objections I've thought of already.

Why should we care what impresses or doesn't impress you?

Since I'm not a particular authority on ghosts, the fact that something doesn't impress me may not be earth-shaking. It's not the fact that these things don't impress me that's important; it's the fact that there are normally mundane explanations. I just didn't want to call the list "Things That Shouldn't Impress Anyone", since I'm not in the business of telling people what to think.

It's hardly a skeptical attitude to dismiss an entire class of phenomena!

Agreed– and that's why this is a list of the unimpressive, not of the worthless. If a level door closed by itself in an airtight room, that would be worth investigating. In real-world situations, though, the sheer number of reasons for a door to close makes it hard to eliminate every single mundane cause. If something on this list wants to be evidence, it's got some work to do.

You can't prove that X wasn't caused by a ghost. How can you dismiss potential evidence?

To me, it's only compelling evidence if there is no apparent mundane explanation. If all of the objections are completely eliminated, great– but that means COMPLETELY eliminated. This is not a list of things that are definitely not paranormal. They're just not evidence of the paranormal until they overcome all the objections I've stated and others I haven't thought of.

How can you dismiss things without investigating them?

That's kind of the point– we've seen these things multiple times, and investigating them always turns up the same objections. Hence the list. It's a time-saver and shorthand, not a credo.

What do you find impressive?

Some of the video and FLIR evidence has been impressive enough to warrant further study– the "Black Cat" FLIR from the farmhouse window, for example. I think I presented a decent explanation of that one a few podcasts back, but it was worth some extra work to do so.

So that's my list of Things That Don't Impress Stephen. I'd welcome discussion on any of the items or suggestions for additions.

Update: Changed "Sincere Anecdotes" to "Personal Experiences". Thanks to CrowTRobot.

Further updates: Split the difference on Sincere Anecdotes. Added "Orbs".