SOMEONE would have liked or preferred.

(1)  If you say that SOMEONE would have liked  or preferred something, you mean that they wanted to do it or have it but they did not, often because it was not possible.

• I would have liked a year more in the pleasant climate there in Europe. ( i.e I really liked to have a longer stay there , but it was not possible)
• I would have preferred to stay at home. ( i.e that was my desire but it was not possible or I could not stay due to some circumstantial influences)

(2)  When you say what SOMEONE would have expected or hoped to happen or be true, you are referring to what they, in fact, expected or hoped to happen or what it was reasonable to expect, especially when it did not happen or was not true.

• There were more participants than one would have expected.  (i.e one expected only less)
• The examination was more difficult than the students would have expected.( i.e students expected the examination to be less difficult)
• He found less time than he would have hoped to follow up his private hobbies.
• I wouldn’t have thought it possible.( i.e against what I thought it was possible)

(3) You use would have –ed when you are mentioning something that you are assuming or guessing happened or was true.

• She wouldn’t have seen me.  She was too far away.
• They would have contacted the authorities in time.(i.e it is the assumption that they contacted authorities in time)