Can someone give me some example of how I would use this talent?

It swaps Lore and Force Rating once per session. So for any power check you could use your ranks in Lore as opposed to your FR.

So i can use my lore as a force rating check?

I think you may be over-thinking this. If you have, say, the Move power and have it fairly maxed out with options and normally your Force Rating is 2, but you have a Lore of 5. Then 1 time per session, you can count your Force Rating to be equal to your ranks in Lore. So when the 1 time that you use it you roll 5 Force Dice and use any or all of the pips generated to activate various things in the power.

If the power requires a Discipline or other roll to use, you still need to make that as normal.

So i can use my lore as a force rating check?

Once per session, yes.

So i can use my lore as a force rating check?

For one single check per session, your choice. It can help to look at the full talent description in the talent chapter - page 146.

So i can use my lore as a force rating check?

For one single check per session, your choice. It can help to look at the full talent description in the talent chapter - page 146.

Uhm, does this mean that I can once per session commit ranks of my lore skill into enhance or sense? That is quite a powerful talent.

Yes, but the effecrs last exactly 1 round, at the end, you drop back to regular.

also, remember that committing a Force Die is your action.

No, actually. The talent doesn't change your Force Rating to be your ranks in Lore, it changes the number of dice you roll for one Force power check (one check , i.e. one roll of the dice) to be equal to your ranks in Lore.

This does mean, though, that if your total Force Rating is 3 and your Lore is 4, and you've committed two of Force dice to various powers and/or talents, using Knowledges is Power would still give you four dice to roll.

When you use this talent it doesn't matter what you're total or current Force Rating is, or how many dice you currently have committed, the number of dice you roll is always you're ranks in Lore.

No, actually. The talent doesn't change your Force Rating to be your ranks in Lore, it changes the number of dice you roll for one Force power check (one check , i.e. one roll of the dice) to be equal to your ranks in Lore.

Nope, you are wrong on this, it say literally "when making a single check, the character may threat his force rating as being equal to his ranks in knowledge(Lore). Not dice, but force rating.

But just for one check, now committing dice is a check. Though as this is only working for this one check, you are back to your normal rating afterwards. The question is here, what happens to committed dice when your force rating lowers suddenly … the likely thing would be indeed your avaible force rating is reduced by your committed dice. "However, a character can not commit more force dice than his current Force rating", I don't think this was written for this case and there is no a decent hint how to resolve this, either end the ongoing effect completely or reduce the effect until the FR reaches zero.

Nope, you are wrong on this, it say literally "when making a single check, the character may threat his force rating as being equal to his ranks in knowledge(Lore). Not dice, but force rating.

But just for one check, now committing dice is a check. Though as this is only working for this one check, you are back to your normal rating afterwards. The question is here, what happens to committed dice when your force rating lowers suddenly … the likely thing would be indeed your avaible force rating is reduced by your committed dice. "However, a character can not commit more force dice than his current Force rating", I don't think this was written for this case and there is no a decent hint how to resolve this, either end the ongoing effect completely or reduce the effect until the FR reaches zero.

Committing Force Dice is not a check, it is an action. Universally*, the rules use the word "check," as a game term, to mean "roll." Many actions might require checks to perform, and the vast majority of checks take up your action, but an action (like committing dice) is not the same thing as a check (like testing your Athletics to jump a ravine). Knowledge is Power affects one single check that you make, replacing the normal number of dice you would roll with a number equal to your ranks in Lore.

Additionally, please read the section on committing Force Dice carefully (note I don't have my books directly in front of me so I'm going off memory, but my memory is fairly sharp). When you commit Force Dice, your actual Force Rating diminishes by the number of dice committed. A person with FR 2 who commits to the defensive Sense upgrade now has a Force Rating of 1 for all game effects, until she ends that ongoing effect, at which point her Force rating increases by the number of dice committed to it. The line you quote is simply a way of reinforcing to readers, "You can't commit 3 dice to an effect if your current Force Rating is 2."

I know it is very easy to think of Force Rating as a whole: you have Force Rating 4, 2 of which is free and 2 of which is committed; I myself do this as a convenient shorthand. But that's not what's actually happening. Instead, in the given scenario, you have Force Rating 2, and a commit effect that required 2 Force Dice to activate. So if you have 4 ranks in Lore and activate Knowledge is power, your Force Rating of 2 is replaced by your ranks in Lore, and you roll 4 Force Dice.

Incidentally, Survival of the Fittest works the same way, only substituting Survival for Lore.

* If you can find an instance where this is not the case, and the rules refer to an action that does not require a dice roll as a "check," I may reconsider your argument.

EDIT: I like to consider talent obsolescence when determining how such talents work, to ensure unique, thematic talents are still relevant at all XP levels. Knowledge is Power and Survival of the Fittest are two very thematic talents, unique to their specializations, and are usable once per session. If they were to replace your ranks in the Force Rating talent with your ranks in a skill, instead of replacing your current Force Rating (two different things), then once you reach Force Rating 5 the talents are worthless, literally wasted XP. Regardless of commits, you could never again gain a benefit from them.

If instead it replaces your current Force Rating, which is also the interpretation my reading of the rules themselves supports, then they allow, once per session, a slight boost in Force power versatility to those high-level characters, as long as they've also committed a not-insignificant amount of XP to the appropriate skill.

Checks and committing dice are clearly laid out as separate ideas in the Force section, they're both Actions but the section specifically points out committed dice aren't available for checks. The term 'check' is always used in conjunction with putting a dice pool together. I wouldn't allow this to be used for committing Force dice.