I am applying for some postdoc programs and have come across a requirement called "motivated letter of application" which I assume is essentially similar to what many here refer to as statement of purpose.

Since I never had to write such a letter before I am not quite sure what it should contain. I couldn't find any specific instructions regarding the letter so I wonder whether or not there are general (subject-agnostic) guidelines or expectations regarding this type of personal letter.

Is it essentially about:

  1. who I am, or
  2. what I have done so far, or
  3. what I want to do in the future, or
  4. why I am applying to this specific position?

(1) is essentially answered by the CV, so it would be mostly re-iterating the same stuff in a less verbatim/list format.

(2) is again answered partially by the CV and partially by the list of publications and thesis.

That leaves (3) and (4), where the first one is dependent on what resources I can get. I mean, coming from a cross-disciplinary field I can imagine developing towards a number of different fields. I don't feel like there is one very specific thing/project I want to do. Finally, (4) is also a bit tricky to answer, since the truth would be as simple as, "it's a cool position". The more elaborate answer would be something like "I like the project description and consider myself fulfilling the requirements"

Those of you who do read such letters of motivation, what do you actually look for in specific terms? Things like "suitability of the candidate" doesn't help much in terms of structuring the letter, I think.