Oded Goldreich

Answers to Frequently Asked Questions and Requests

This webpage is NOT intended for Weizmann students, postdocs and/or faculty members. My duties towards them are definitely incomparable to my duties towards the community at large. In particular, I will be happy to answer any question or request they may have, regardless if it is on the following list or not.

This webpage is also NOT intended to discourage requests that are not explicitly mentioned in it. As you will see, I do not shy to list the type of requests that I will refuse, so please don't assume that I'll refuse an unlisted type of request.

Preface: It is great to live in an era that allows rapid and convenient communication. Yet, also good things have dark sides: The amount of communication grows, and consequently the total time spent in communication may grow rather than decrease. In particular, at times I get more questions and requests than I can possibly handle, especially if I am to continue doing other things. Since some of the questions and requests keep recurring, I am posting my answers below.

This page includes frequently asked questions and requests regarding

• graduate studies at the Weizmann Institute (FGS/WIS) and being my student,
• PostDoc-ing at the Weizmann Institute (FGS/WIS),
• Applying for a faculty position at the Weizmann Institute,
• my areas of past and present expertise and my papers and books,
• my areas of non-expertise (e.g., Applied Cryptography),
• consulting (non-interest).
• general advice.
• review requests.

About Graduate Studies at the Weizmann Institute (FGS/WIS)

All graduate studies at the Weizmann Institute of Science (WIS) are administrated by the Feinberg Graduate School (FGS). Applications should be made using the school's forms which can be obtained together with more detailed information from the FGS homepage. You may also contact the school via e-mail (nfinfo@weizmann.ac.il) or by ordinary mail to the Feinberg Graduate School, P.O.B 26, Rehovot, Israel.

Following are my view regarding certain questions.

• Q: Who can apply to Graduate Studies at FGS/WIS?
  Formally, anybody with an undergraduate degree can apply to graduate studies in computer science at FGS/WIS. However, we tend not to admit applicants lacking good background in computer science; that is, we expect applicants to have good knowledge of algorithms (rather than good programming skills).

  PhD versus Master: Please note that an application to PhD studies requires an adviser (i.e., a statement by a faculty member that he/she is willing to serve as an adviser for the candidate), whereas an application to Master studies does not require an adviser. On the other hand, one can enter our PhD studies at any point in time, whereas entering our Master studies is only possible at the beginning of each Fall (typically, October).

• Q: Who should apply to Graduate Studies at FGS/WIS?
  Assuming that you can apply to our graduate studies, you should ask yourself whether you are indeed interested in what our graduate studies program has to offer. Note that we do not cover uniformly all areas of Computer Science, but rather specialize in several areas. Specifically, we have very strong research groups in Foundations of Computer Science and in Computer Vision. In general, our areas of expertise are the sum of the areas of expertise of our faculty. Thus, it is recommended to look at the homepages of the faculty in order to find out more information about what we have to offer.

• Foreign (non-Israeli) students.
  We encourage applications by foreign (non-Israeli) students. In fact, the Weizmann Institute is the only institute in Israel in which all research and teaching activity is conducted in English (rather than in Hebrew). However, in some cases applications from foreign countries are harder to evaluate (especially, in case the undergraduate degree is from a less known institute). Furthermore, a decision is taken without an interview (whereas local applicants are typically invited to a personal interview). The situation is even worse when applying to our PhD program, because such an application must be supported by a faculty that is willing to advise the student (see above). We therefore make the following recommendations:
  • Unless you have a master degree from a top university, apply to the Master program rather than to the PhD one. Note that it may be possible to later switch to the PhD program (see ``direct PhD'' below).
  • Obtain letters of recommendations from people who know you and who are known internationally.

• Admission standards (or chances of being admitted).
  Our admission standards are quite high, and we typically have more suitable candidates than the number of fellowships that we can offer (all regular graduate students get fellowships). In certain cases, we propose to suitable candidates to join our non-regular program, which does not offer fellowships. Typically, this is done when the candidate plans to continue to work concurrently to his/her studies (students with fellowships are not allowed to maintain outside jobs). Furthermore, unless specified otherwise, we assume that a foreign candidate is not interested in this possibility.

• Insufficient background.
  Sometimes, people who lack the suitable background apply to our programs because they are interested in graduate studies in computer science. We typically recommend to such people to first obtain the suitable background elsewhere (e.g., in courses given by the Open University, etc). Recommended courses include courses on the Design and Analysis of Algorithms, and an Introduction to Computability and Complexity Theory.

• The direct-PhD program.
  Typically, to be admitted as a PhD student, one should have a master degree. However, there is a possibility of doing a ``direct PhD'' (without a Master degree). Typically, one can enter the `direct PhD' program only via the master program. That is, if you are interested in a `direct PhD' then you should enroll to the master program and perform outstandingly well there. In such a case, your master adviser may recommend that you pass to the `direct PhD' program.
  I, personally, do not consider the difference between `direct PhD' and `Master first and PhD afterwords' to be very important. For sure there are some benefits in the `direct PhD' program (e.g., less course-work), but even they may turn out to be disadvantages in some cases (e.g., less time in graduate studies). Thus, I usually recommend to my students not to take this program. In any case, the important thing is the substance (i.e., the study and research itself).

• Entering a student-adviser relationship
  My own view/policy is that a student-adviser relationship is something very demanding, and that one should not enter it without proper two-sided "evaluation" (in the sense of each of the parties seeing that the other is suitable for him/her). Thus, I personally will not agree to serve as an adviser of a person whom I do not know well enough (e.g., a person that I only know via email correspondence). This means that, typically, I will not agree to consider serving as an adviser of a person that I never met or have just met. My decision can be based only on seeing the candidate cope with research problems, which may allow me to see if we fit (regardless of the success or failure in coping with these research problems).
  Needless to say, the phrase ``person that I have never met'' does not include Weizmann students, let alone ones that I have seen in courses and/or seminars. In such cases a process of mutual estimation of ``fitness'' can be conducted at leisure and with much lower level of stress (especially on me...).

• On being my student
  The following information may be relevant to you in case you consider becoming my student.
  • In general, I am interested in working with students on topics of my expertise in areas such as Randomness and Computation, Property Testing, Complexity Theory, and Foundations of Cryptography. I have no expertise in applied aspects of cryptography.
    Actually, in recent years, I have not been actively interested in the Foundations of Cryptography, and so it may not be a good idea for me to advise students who are interested in doing research in this area.
  • In general, my approach to advising is extremely hands off; I advise the students on whatever they wish and I feel knowledgeable about. I typically do not work with them, and I do not assume responsibility for offering problems, although sometimes I do...
    Typically, I do not have concrete/specific research projects to offer, but rather expect such suggestions to come from the student. What I can offer is mainly constructive criticism.
  • In general, I will not serve as adviser to part-time students.
  (This entry [as well as the preceding one] is neither meant to be discouraging nor encouraging candidates. I merely try to be informative. And, if you wonder, yes I did have some students in the past...)

• Summer students: For a variety of reasons, I am not interested in having summer students. Other WIS faculty may be interested in this venture.

About PostDoc-ing at the Weizmann Institute (FGS/WIS)

Postdocs at the Weizmann Institute of Science (WIS) are administrated by the Feinberg Graduate School (FGS). Applicants are expected to contact a potential host, but the host is not the one deciding on the application; all decisions (including funding) are determined at the faculty level. Details regarding the application and selection procedures can be found at the relevant webpage of FGS.

Some of the comments made above regarding entering a student-adviser relationship and being my student apply also to postdocs, but indeed to a lesser extent.

Applying for a faculty position at the Weizmann Institute

The best scientists at Weizmann are not necessarily better than the best scientists in other universities in Israel, but the typical scientists at Weizmann are better than the typical scientists at other places. [Haim Harari, former president of Weizmann, 1988-2001]

In the early 1990s, the Weizmann Institute decided to revise its hiring policies so to minimize the chances of not granting tenure to scientists. Accordingly, the hiring process was transformed to being more critical, and includes the solicitation of half a dozen external evaluations of the candidate and careful deliberation in four different faculty and institutional bodies.

Since our hiring process involves more steps and takes more time, it is advised to apply to us a couple of months prior to applying to other universities in Israel. This is particularly the case, since several universities have a (vicious) practice of making offers with a quite short expiration time, whereas Weizmann does not put pressure on the scientists it wishes to hire. To be concrete, interested candidates are encouraged to apply by September 1st, although applications will be considered on a continuing basis.

I am happy to be a faculty at Weizmann, and would not trade my position here for any position anywhere in the world. [Oded, anytime since 1994...]

About My Areas of Past and Present Expertise

My past areas of expertise are Randomness and Computation, Foundations of Cryptography, and Complexity Theory, but for more than a decade I have not been following research in the Foundations of Cryptography and hence can no longer be considered an expert in that field.

The fact that I have expertise in some areas does not mean that I can afford to answer typical questions and requests that are referred to me regarding these areas. In particular, I cannot afford to offer research problems, and typically (see exception clause below) cannot afford to evaluate new work or answer various questions about existing work (including my own). Details follow.

• Q: Could you offer some ``good'' research problems?
  No. Of course, there are many well-known open problems (few offered by myself); these can be found in various surveys and papers, but suggesting these to somebody seeking a ``good'' (i.e., tractable and nice) research problem is not very wise. Suggesting `tractable and nice' research problems is very difficult; in the rare cases that I manage to come across such a problem, I work on it myself or suggest it to my own students.

• Q: Could you read and/or evaluate an enclosed work or idea?
  Typically not (but see exception clause below). I cannot even afford to superficially read and/or evaluate all work and ideas sent to me. Let alone, that I cannot afford to provide a non-superficial evaluation of all work that do merit such an evaluation. Typically (i.e., unless the work/idea is obviously wrong or commonly known), it is very hard to provide a useful evaluation of a scientific work or idea.

• Q: Could you explain this or that?
  Maybe (i.e., preferably not, but see exception clause below). I may try to answer technical or conceptual questions that you may have, but do try to seek alternative ways before asking my help. In particular, try to think hard of the question before asking me; you will learn much more this way and in addition you will help ensure that I have the time me to answer the few questions that seem to require my help.
  Please bear in mind that I cannot afford to answer all specific questions (even regarding only my areas of expertise) that are referred to me. Thus, I ask you to assist me in focusing on answering only questions that seem to require my specific expertise. These are very few.

• Questions about my papers and my books
  Again, try to resolve these by yourself. (Please take into account that it is not reasonable to expect me to answer individually each reader of my papers. Again, see exception clause below). That is, I ask you to assist me in focusing on answering only questions that seem to require my specific expertise. These are very few.

• Q: Can you send me solution manuels for your book(s) or any material not found on your website?
  In general, I posted all my web-site all material that I can afford to share with others. This includes various versions of my papers, various drafts of my books, etc. If some material (e.g., solution manuels for my books or old papers) is not posted, then it is almost certain that I do not have it.

About My Areas of Non-Expertise (e.g., Applied Cryptography)

I believe that sound practice of Cryptography has to be based on firm theoretical foundations. Still, this necessary condition is not sufficient, and expertise in applied (or practical) aspects of cryptography requires more than understanding of the theoretical foundations of Cryptography. For example, although I considered myself (in the past) an expert on the theoretical foundations of Cryptography, I never had more than very little knowledge of the applied (or practical) aspects of cryptography. In particular, please do not ask me to evaluate the security of any specific construct.

About Consulting

My above statement of limited knowledge of the applied (or practical) aspects of cryptography means that I'm not the right person to ask for consulting regarding the latter aspect. On top of this, I am not interested at all in consulting to or being involved in any commercial enterprise. My main reason is my unwillingness to make any commitment to spend time on anything other than my research and personal interests. Unfortunately, for lack of time, I properly pursue only a tiny part of my research and personal interests, and I have no intentions of making this part even smaller.

Asking for general advice

I cannot possibly provide personal advice (e.g., regarding studying cryptography) to anybody who may seek it. Giving such advice requires learning the person and his/her specific needs, which I really cannot afford. Whatever general (or generic) advice I can give, can be found in my web-pages (starting from my homepage).

Regarding review requests

Being an editor of a few journals, I do sympathize with the effort of editors seeking adequate referees for submitted papers. However, being overloaded by referee requests, it is my policy to decline any request that does not require my specific expertise and can be handled as easily by dozens of other researchers. (Even under this policy, I'm handling a lot of review requests...) Needless to say, I will definitely decline referee requests that refer to works that do not lie in the core of my research expertise (see above). But what I am saying here is that I may decline even requests that refer to this core.

Using web-servers for review: Due both to practical and principled reasons, I will refuse to use web-servers for submitting reviews and/or recommendation letters.

Again, this webpage is also NOT intended to discourage requests that are not explicitly mentioned in it. As you can see, I do not shy to list the type of requests that I will refuse, so please don't assume that I'll refuse an unlisted type of request.