Hi, any pal cares to help me clarify with the following?

1. How long should the recommendations be? Which style is better, detailed or concise?

2. Should it provide supporting examples for all recommended virtues? How many expamples are enough for each point?

3. Should the two recommenders address different aspects of you? Or should they both emphasize certain strength to make it look more coherent?

Yes, Columbia asks each recommender 10 questions!

but what if i ask the recommender to write one letter rather than aswer each question of each school?
by the way, which way is better? answering the questions or writing a general letter?

Answer the question is always the better choice. However it takes more time.

I've heard it will be ok as long as your Recom letter is less than 7 pages!

I guess that it really depend on the schools. I hear that the recommendation letter shoud be no less than 1 page and each is focused one of your key advantages. Just for your reference. Why not ask the admission office for their advice?

Answering the questions is the best one but most schools understand how busy your recommender is so a letter is quite acceptable. I summarized the common questions from various schools and ask recommender to write only one letter when I applied.

Normally, 600-1000 words are OK. But it really depends on whether the letter has "truly rich" content.

BTW, most schools' online system has word limit for answering each question.