If you had to pick a problem that is closest to each difficulty (as you think of it) which 5 problems would you pick?

Another way of thinking of this is if someone new came on the site (who read the existing problems), which ones would you choose to demonstrate each difficulty level?

I think it's also a matter of which category the problems are in. I don't think that you can compare D5 problems categorized in Riddles vs Calculus vs Logic vs Word Problems. Indeed, the categories themselves seem to attract puzzles of different average difficulties - there are almost no D5 riddles, very vew D5 logic problems, yet plenty of D5 problems in the math categories.

Anyway, any particular reason for this list?

I mostly was interested in what people thought various difficulties meant.

Lots of problems have the D3 rating which has become the average on perplexus. I don't know which problem I would choose for that.

For me, a D2 problem would take some effort to solve, where as a D1 could be solved rather quickly. For example, many tricks problems like The Famous Horse are easy once you know the answer.

D4 problems are a harder than than the average problem. For example, Lucky Numbers and Sophie Squares. D5 are the ones that surpass the D4 rating and require a real in depth solving technique or solution. Since D5 is the highest it goes, it might not be given out often since it doesn't match the difficulty of harder problems. Whether or not this is a problem, I am not sure.

One of the interesting things about problems is easy ones can be made harder by adding conditions or variations. For example, Charlie identified the chance of winning 100 or 1000 in The Carnival Game, http://perplexus.info/show.php?pid=1232&cid=7997 Robust proofs are also a good way to make the problem harder. Coming up with a solution to Battleships is fine, but it's also interesting to prove why that solution is the best.

5: Unique Necklaces
4: Lucky Numbers
3: Battleships
2: Black Jack
1: Mixing Digits

5: Charlie can solve it with a computer
4: Jer can solve it using the internet
3: Vernon Lewis can solve it, in spite of mutliple typos
2: Penny can solve it with her eyes closed
1: Hugo can solve it, unless he is distracted by his screensaver

Mindrod, difficulty 1: would that be the same Hugo that solved "The Conversing Club 3"?
:)
Indeed, from time to time I am distracted by the problems and then take my eyes off my screensaver.

Let the record show that Hugo is a highly intelligent individual, capable of solving a wide variety of problems of varying difficulty...as long as his screen saver isn't running. Or unless Percy has tickets to "Brokeback Mountain" and is knocking at the door again.

I think that Gamer may have raised this here after I raised the issue in the JM forum where there was a note that one puzzler appeared to be posting all puzzles at D5.

While some sort of guidance would be useful, I agree that difficulty comes perception and that what applies within area is unlikely to be relevant in another.

My consideration is to attempt to preempt who might be my audience, and if it can be placed somewhere in a school curriculum eg Junior High (D2, D3) but I know that won't always work.

Cryptography will also depend upon the encryption used and any wiliness employed by the poser of the problem.

Some people's minds have a great 'housekeeper'.

Larry, I am some times well organised, but then there are things which become clutter (note "some times" as against "sometimes", there is a real difference).

I think that you somewhat clarify the difficulty that many of us must face when attempting to assign the level of challenge.

Given some thought, such a scale looks feasible. Without too much fuss it could be applied to Riddles, Calculus problems, Literature, Crytography ....

Yes. I like this.

Come on in. The water is fine. Float your thoughts too.

Crytography is the art of writing on the very small appendages at the tips of frozen feet, a pedantic pedicure for popsicle toes.

Something creative, funny and/awry please.

How do people survive such places? In my case (Vietnam 1969) because the alternative to survival was not an option. I know this is not funny or creative but it is simply the truth.
You are so lucky to be in Victoria, Australia where you get four seasons not just every day but usually every hour.

Absolution granted, Jer. My first difficulty rating post was intended for entertainment purposes only.

I agree with you that D3 should be the default rating for anyone who in unsure how difficult the problem might be in comparison to "the norm". (Isn't D3 the default already?)

I'm not convinced the difficulty rating is all that useful or important. Is it intended to steer folks away from certain problems, or make a problem appear more attractive? Problems aren't sorted by difficulty rating, and you can't use difficulty rating as a search criterea, so why is it there? I'm sure there's a forum posting somewhere that could provide an explanation. Please excuse me for a few hours while I go looking for it.

I think difficulty is meant to give an indication to solvers of how hard the problem is to solve. It is also useful for deciding whether the solution is complex or easy.