How To Write A DissertationorBedtime Reading For People Who Do Not Have Time To Sleep--------------------------------------------------------------------------------To The Candidate:So, you are preparing to write a Ph.D. dissertation in an experimental area of Computer Science. Unless you have written many formal documents before, you are in for a surprise: it's difficult! There are two possible paths to success: Planning Ahead. Few take this path. The few who do leave the University so quickly that they are hardly noticed. If you want to make a lasting impression and have a long career as a graduate student, do not choose it. Perseverance. All you really have to do is outlast your doctoral committee. The good news is that they are much older than you, so you can guess who will eventually expire first. The bad news is that they are more practiced at this game (after all, they persevered in the face of their doctoral committee, didn't they?). Here are a few guidelines that may help you when you finally get serious about writing. The list goes on forever; you probably won't want to read it all at once. But, please read it before you write anything. --------------------------------------------------------------------------------The General Idea:A thesis is a hypothesis or conjecture. A PhD dissertation is a lengthy, formal document that argues in defense of a particular thesis. (So many people use the term "thesis" to refer to the document that a current dictionary now includes it as the third meaning of "thesis"). Two important adjectives used to describe a dissertation are "original" and "substantial." The research performed to support a thesis must be both, and the dissertation must show it to be so. In particular, a dissertation highlights original contributions. The scientific method means starting with a hypothesis and then collecting evidence to support or deny it. Before one can write a dissertation defending a particular thesis, one must collect evidence that supports it. Thus, the most difficult aspect of writing a dissertation consists of organizing the evidence and associated discussions into a coherent form. The essence of a dissertation is critical thinking, not experimental data. Analysis and concepts form the heart of the work. A dissertation concentrates www.gxqingyuan.com on principles: it states the lessons learned, and not merely the facts behind them. In general, every statement in a dissertation must be supported either by a reference to published scientific literature or by original work. Moreover, a dissertation does not repeat the details of critical thinking and analysis found in published sources; it uses the results as fact and refers the reader to the source for further details. Each sentence in a dissertation must be complete and correct in a grammatical sense. Moreover, a dissertation must satisfy the stringent rules of formal grammar (e.g., no contractions, no colloquialisms, no slurs, no undefined technical jargon, no hidden jokes, and no slang, even when such terms or phrases are in common use in the spoken language). Indeed, the writing in a dissertaton must be crystal clear. Shades of meaning matter; the terminology and prose must make fine distinctions. The words must convey exactly the meaning intended, nothing more and nothing less. Each statement in a dissertation must be correct and defensible in a logical and scientific sense. Moreover, the discussions in a dissertation must satisfy the most stringent rules of logic applied to mathematics and science. What One Should Learn From The Exercise:All scientists need to communicate discoveries; the PhD dissertation provides training for communication with other scientists. Writing a dissertation requires a student to think deeply, to organize technical discussion, to muster arguments that will convince other scientists, and to follow rules for rigorous, formal presentation of the arguments and discussion. A Rule Of Thumb:Good writing is essential in a dissertation. However, good writing cannot compensate for a paucity of ideas or concepts. Quite the contrary, a clear presentation always exposes weaknesses. Definitions And Terminology:Each technical term used in a dissertation must be defined either by a reference to a previously published definition (for standard terms with their usual meaning) or by a precise, unambiguous definition that appears before the term is used (for a new term or a standard term used in an unusual way). Each term should be used in one and only one way throughout the dissertation. The easiest way to avoid a long series of definitions is to include a statement: "the terminology used throughout this document follows that given in [CITATION]." Then, only define exceptions. The introductory chapter can give the intuition (i.e., informal definitions) of terms provided they are defined more precisely later. Terms And Phrases To Avoid:adverbs Mostly, they are very often overly used. Use strong words instead. For example, one could say, "Writers abuse adverbs." jokes or puns They have no place in a formal document. "bad", "good", "nice", "terrible", "stupid" A scientific dissertation does not make moral judgements. Use "incorrect/correct" to refer to factual correctness or errors. Use precise words or phrases to assess quality (e.g., "method A requires less computation than method B"). In general, one should avoid all qualitative judgements. "true", "pure", In the sense of "good" (it is judgemental). "perfect" Nothing is. "an ideal solution" You're judging again. "today", "modern times" Today is tomorrow's yesterday. "soon" How soon? Later tonight? Next decade? "we were surprised to learn..." Even if you were, so what? "seems", "seemingly", It doesn't matter how something appears; "would seem to show" all that matters are the facts. "in terms of" usually vague "based on", "X-based", "as the basis of" careful; can be vague "different" Does not mean "various"; different than what? "in light of" colloquial "lots of" vague & colloquial "kind of" vague & colloquial "type of" vague & colloquial "something like" vague & colloquial "just about" vague & colloquial "number of" vague; do you mean "some", "many", or "most"? A quantative statement is preferable. "due to" colloquial "probably" only if you know the statistical probability (if you do, state it quantatively "obviously, clearly" be careful: obvious/clear to everyone? "simple" Can have a negative connotation, as in "simpleton" "along with" Just use "with" "actually, really" define terms precisely to eliminate the need to clarify "the fact that" makes it a meta-sentence; rephrase "this", "that" As in "This causes concern." Reason: "this" can refer to the subject of the previous sentence, the entire previous sentence, the entire previous paragraph, the entire previous section, etc. More important, it can be interpreted in the concrete sense or in the meta-sense. For example, in: "X does Y. This means ..." the reader can assume "this" refers to Y or to the fact that X does it. Even when restricted (e.g., "this computation..."), the phrase is weak and often ambiguous. "You will read about..." The second person has no place in a formal dissertation. "I will describe..." The first person has no place in a formal dissertation. If self-reference is eesential, phrase it as "Section 10 describes..." "we" as in "we see that" A trap to avoid. Reason: almost any sentence can be written to begin with 'we" because "we" can refer to: the reader and author, the author and advisor, the author and research team, experimental computer scientists, the entire computer science community, the science community, or some other unspecified group. "Hopefully, the program..." Computer programs don't hope, not unless they implement AI systems. By the way, if you are writing an AI thesis, talk to someone else: AI people have their own system of rules. "...a famous researcher..." It doesn't matter who said it or who did it. In fact, such statements prejudice the reader. Be Careful When Using "few, most, all, any, every". A dissertation is precise. If a sentence says "Most computer systems contain X", you must be able to defend it. Are you sure you really know the facts? How many computers were built and sold yesterday? "must", "always" Absolutely? "should" Who says so? "proof", "prove" Would a mathematician agree that it's a proof? "show" Used in the sense of "prove". To "show" something, you need to provide a formal proof. "can/may" Your mother probably told you the difference. Voice:Use active constructions. For example, say "the operating system starts the device" instead of "the device is started by the operating system." Tense:Write in the present tense. For example, say "The system writes a page to the disk and then uses the frame..." instead of "The system will use the frame after it wrote the page to disk..." Define Negation Early:Example: say "no data block waits on the output queue" instead of "a data block awaiting output is not on the queue." Grammar And Logic:Be careful that the subject of each sentence really does what the verb says it does. Saying "Programs must make procedure calls using the X instruction" is not the same as saying "Programs must use the X instruction when they call a procedure." In fact, the first is patently false! Another example: "RPC requires programs to transmit large packets" is not the same as "RPC requires a mechanism that allows programs to transmit large packets." All computer scientists should know the rules of logic. Unfortunately the rules are more difficult to follow when the language of discourse is English instead of mathematical symbols. For example, the sentence "There is a compiler that translates the N languages by..." means a single compiler exists that handles all the languages, while the sentence "For each of the N languages, there is a compiler that translates..." means that there may be 1 compiler, 2 compilers, or N compilers. When written using mathematical symbols, the difference are obvious because "for all" and "there exists" are reversed. Focus On Results And Not The People/Circumstances In Which They Were Obtained:"After working eight hours in the lab that night, we realized..." has no place in the dissertation. It doesn't matter when you realized it or how long you worked to obtain the answer. Another example: "Jim and I arrived at the numbers shown in Table 3 by measuring..." Put an acknowledgement to Jim in the dissertation, but do not include names (even your own) in the main body. You may be tempted to document a long series of experiments that produced nothing or a coincidence that resulted in success. Avoid it completely. In particular, do not document seemingly mystical influences (e.g., "if that cat had not crawled through the hole in the floor, we might not have discovered the power supply error indicator on the network bridge"). Never attribute such events to mystical causes or imply that strange forces may have affected your results. Summary: stick to the plain facts. Describe the results without dwelling on your reactions or events that helped you achieve them.