There are a great many ideas which don't have enough carefully-measured evidence to be sufficiently confirmed as scientific fact and accepted as such by the scientific community (a recent joke was "While the Higgs Boson has not been discovered yet, its mass is 125 GeV"), but don't have enough carefully-measured evidence to be ruled out yet, either. Do any of the tools of the LW community help narrow down which ones are more worthy of consideration than others?
Eg:
* Cryonics as an arguably reasonable bet for its cost: proto-science
* Cryonics as a surefire way to achieve immortality: nigh-certainly pseudoscience (unless it's the method by which your Everett Immortality keeps you alive)
* Using math to demonstrate that taking classical physics and adding determinism results in MWI-style quantum physics: proto-science.
* Using math to demonstrate that quantum physics proves Christianity is true, from a certain point of view: pseudo-science
* Tubulin might self-organize into microtubules capable of computation on a sub-neuron scale: Possibly proto-science
* Tubulin architecture is 'quantum' in nature and that is what gives rise to consciousness: Probably pseudo-science
* 'Quantum consciousness' means anything is possible: Downright silly
* The E8 Lie group can provide a system for organizing the properties of subatomic particles: Proto-science, perhaps
* Heim theory is useful for predicting particle masses: Pseudo-science, probabilistically
* Using the Bullet Cluster to claim that dark matter is a better theory than Modified Newtonian Dynamics: proto-science
* Claiming that dark matter is made of 'anapoles': Proto-science, perchance
* Suggesting that dark matter is actually gravitational leakage from MWI 'parallel universes': You tell me. (But if it's true, then since I can't seem to find any previous serious discussion of this idea, I get to name part of it after myself, right? :) )
These may not be the best examples, but they're the closest ones I can think of to the boundary. If you know of any better ones, feel free to comment with them.
My own definition - proto-science is something put forward by someone who knows the scientific orthodoxy in the field, suggesting that some idea might be true. Pseudo-science is something put forward by someone who doesn't know the scientific orthodoxy, asserting that something is true.
Testing which category any particular claim falls into is in my experience relatively straightforward if you know the scientific orthodoxy already - as a pseudoscientist's idea will normally be considered absolutely false in certain aspects by those who know the orthodoxy. A genuine challenger to the orthodoxy will at least tell you that they know they are being unorthodox, and why - a pseudoscientist will simply assert something else without any suggestion that their point is even unusual. This is often the easiest way to tell the two apart.
If you don't know the orthodoxy, it's much harder to tell, but generally speaking pseudoscience can also be distinguished a couple of other ways.
Socially - proto-science advocates have a relevant degree on the whole, and tend to keep company of other scientists. Pseudo-science advocates often have a degree, but advocate a theory unrelated to it, and are not part of anything much.
Proof - pseudo-science appeals to common sense for proof, wheras proto-science only tries to explain rather than persuade. Pseudo-science can normally be explained perfectly well in English, wheras proto-science typically requires at least some mathematics if you want to understand it properly.
Both look disappointingly similar once they've been mangled by a poor scientific journalist - go back to the original sources if you really need to know!
This seems like an excellent heuristic to me (and probably one of the key heuristics people actually use for making the distinction), not not valid as an actual definition. For example, Sir Roger Penrose's quantum consciousness is something I would classify as pseudoscience without a second thought, despite the fact that Penrose as a physicist should know and understand the orthodoxy of physics perfectly well.