My Alsatian was protection trained, as is one of my Collies, with positive methods only.
[ My father was a military handler who helped me with my Alsatian and he refused to allow negatives for his training ].

Whatever a dogs `job`, making that learning rewarding will get better results than punishing because dogs by their nature would rather hear a kind tone than a negative one.

Sheep chasing, yes its certainly possible, with someone who knows what they are doing and sets the dog up to succeed.
If any owner has a sheep chaser, if they are not skilled in reforming the dog, then imo they should use one of two very useful methods - either keep the dog on lead around sheep or not walk the dog where there are sheep

As to how, in brief, it would be best done on normal lead initially with consistant rewarding for focussing on handler instead of the sheep, then when consistant using a longer lead, and gradually building up to a long line [ on harness ], preferably in a set up situation in which the sheep will not be allowed to come to any harm or stress, hence best done with the assistance and guidence of someone experienced in this.
In other words, the handler needs to make themself more appealing than the sheep, and if they are unable to achieve that, then keeping a dog on the lead or avoiding putting a dog in that situation are the most sensible and responsible recourses imo.

Lets put a different slant on this as it would be too easy to just say `this is what I do, or would do, myself in this or that situation `

Imagine you were given a brief for an exam for this scenario in which you were not allowed to use negative tones or touch to achieve the result you want. Therefore you have to think of alternatives or you would fail the exam.
What can you think of which might get you a pass ?

Awwwwwww you answer othe people you ain't playin' fair!!! :smt002

What could I do?
1) Draw the people concerned daggers and tell 'em to stop bugging my bloomin' dog .
2) Anticipate and hold the lead more firmly and engage the dog with a nice lump of cheese.
3) Wear a big sign saying 'my dog is easily distracted please don't look at it..at all!!!!'
4) Don't cross roads when there are lots of people about.
5) Train a good 'leave it ' command and use that.
6) Make the dog sit and look at the handler rather than at the people.
7) Move away if safe...
Pull a squeaky toy from my pocket with which to engage the dog.
9) Get the dog into a stand and tickle it.
Don't get me wrong...I can (and do!!!) do it!!! :smt002
The specific scenario I'm thinking of though is the one I outlined...BUT with a dog that just wants the people, not the treat or the food or the tickle or the toy...in a confined space in the middle of a busy duel carriageway waiting to cross when the lights change, having crossed one side of the road already. (If you see what I mean)...lots of people waiting, no room to manouvere...people coo at dog, dog spots them dog goes to jump up...you feel the lead go...you shout name in a high pitched bright, but non stressed voice, but you can see by those ears, head and tail carriage this dog is about to leap....onto an old lady....do you use the lead to correct it...or do you let it just go as NOTHING is getting this dogs attention back as it has attention form the eye contact it has established in a split second form the other person...
In that case..I would use the lead to correct, with a verbal correction and an immediate praise and reward when the dog looked at me and had its legs all on the ground. I would rather that than risk injury to another person or to the dog, if it fell into the road....I think....

I think in some scenarios it's impossible to react quickly enough to reach into a pocket for a treat or toy and so having a "no" or "leave it" command is useful.

I agree. It is easy to train positively when you can predict what is going to happen, but what when you can't?

:smt077
Seriously though, if I had just answered, would you have come up with such great list of possibilities ?
And I knew you would think about it, you should`nt be so good at thinking things through if you don`t want little challenges passed your way

Particularly good ones would be :

You have some very good ones there and ideally, these are things useful for all handlers to work on as basic training, gradually building up the potential distractions until the dog can be fairly expected to cope with the suggested situation *before* being placed in it, and to be prepared to pre-empt by having the reward already to hand which has been the one successfully used during the basic training, plus to realistically have an attitude of assumption at all times that any dog `may` react unpredictably so as to minimise what `might` occur :smt001

To give you an example, my Gremlin in particular is a very sociable girl who would love to say hello to everyone so I did specifically work on focus with her. She has a trained cue for stopping at kerbs, a release cue so she will only move forward from the kerb on that cue no matter what, an `away` cue [ a leave basically ` ], and a specific cue which I give her for when its ok for her to greet people, [ if the person wants to be greeted by a clumsy waggly collie ]

I did build everything steadily for her and by making everything positive at each stage she enjoys responding to and carrying out the relevent actions and giving her that level of interaction during training increased her confidence hugely. She was a horrendously severe abuse case and her desperation to get fuss off people was based, I believe, in just that - desperation.
Now, she is happy and patient as she has learned that a certain sequence of rewarded behaviours, whatever the situation, [ calmness, a solid sit, a good wait until release, and the verbal cue for greeting people which in her case is `Say Hi` ], brings the further reward of the anticipated cuddles and fuss.

Turning things the other way around, imagine if you will, someone using negative inforcement to stop a dog going to the friendly, [ ir unthinking ], people who are being much nicer toward him or her - what might that negative handling encourage the dog to do - stay by the handler or try as hard as possible to get to the more `positively behaving` people over the road ?

[QUOTE=Patch;848971]
For a sheep dog the greatest reward is to be allowed to continue herding and s*d the handler Sometimes my dog gets so focused on the sheep he forgets I am even there, so I need to use a raised voice in order to get him to listen to me. I am hoping this will only be until he starts responding immediately to my commands, as my trainer very much advocates a soft voice when commanding a dog.

Yep, fair enough

Bearing in mind its not the volume which is so important as the tone and internation used at whatever volume. A loud higher pitched `fun` voice carries further than a loud gruff tone, purely on pitching and dogs hearing, so is more likely to get a response

I guess, but I am not sure a happy, high pitched, fun voice would get him to stop at the precise moment I need him to stop. He seems to respond better to a lower, more growling sort of a tone. If my voice is happy and fun, that indicates to him that the fun can carry on.

As to your first point, could I suggest you don't take my word for it, but read one of John Fisher's books. I think the title is either dogwise or think dog - wysywig will confirm I'm sure. It actually goes through the training with a rescue GSD that passed all the home office testing procedures without ever hearing the word 'no'.

As I said in a previous post, I don't train purely positively as I do train in a non-reward marker (reward being praise, toys, games, food, an ear tickle - whatever the dog likes). The marker, in my case, ah-ah, is not shouted or said harshly, but cannot be said to be purely positive as the reward is not forthcoming if the dog ignores the request.

Training a dog, whether for basic manners or to overcome behaviour problems, is a matter of finding the right motivation for individual dog you are working with. My own two dogs favourite motivators are:

food
praise
coming up on the sofa for a cuddle
a game

In that order for my mixed breed, 8 year old

fetch
tug
praise
cuddles
food

In that order for my border collie who's now 11

They never know which of the rewards they are going to get for any given action

Ah, the wonderful sheep-chaser. Why is it that people think that dogs who like to chase, be it sheep, people, dogs or whatever can't be trained without heavy lead jerks/spray collars/e-collars. Of course they can. Desensitisation (slowly bringing the dog close to the object of excitement and in the process teaching it to keep that excitement under control) and counter-conditioning (satisfying the dogs chasing instinct by teaching it that it's more satisfying to chase something else) are wonderful tools..