thesis phd means

• What Is a PhD Thesis?
• Doing a PhD

This page will explain what a PhD thesis is and offer advice on how to write a good thesis, from outlining the typical structure to guiding you through the referencing. A summary of this page is as follows:

• A PhD thesis is a concentrated piece of original research which must be carried out by all PhD students in order to successfully earn their doctoral degree.
• The fundamental purpose of a thesis is to explain the conclusion that has been reached as a result of undertaking the research project.
• The typical PhD thesis structure will contain four chapters of original work sandwiched between a literature review chapter and a concluding chapter.
• There is no universal rule for the length of a thesis, but general guidelines set the word count between 70,000 to 100,000 words .

What Is a Thesis?

A thesis is the main output of a PhD as it explains your workflow in reaching the conclusions you have come to in undertaking the research project. As a result, much of the content of your thesis will be based around your chapters of original work.

For your thesis to be successful, it needs to adequately defend your argument and provide a unique or increased insight into your field that was not previously available. As such, you can’t rely on other ideas or results to produce your thesis; it needs to be an original piece of text that belongs to you and you alone.

What Should a Thesis Include?

Although each thesis will be unique, they will all follow the same general format. To demonstrate this, we’ve put together an example structure of a PhD thesis and explained what you should include in each section below.

Acknowledgements

This is a personal section which you may or may not choose to include. The vast majority of students include it, giving both gratitude and recognition to their supervisor, university, sponsor/funder and anyone else who has supported them along the way.

1. Introduction

Provide a brief overview of your reason for carrying out your research project and what you hope to achieve by undertaking it. Following this, explain the structure of your thesis to give the reader context for what he or she is about to read.

2. Literature Review

Set the context of your research by explaining the foundation of what is currently known within your field of research, what recent developments have occurred, and where the gaps in knowledge are. You should conclude the literature review by outlining the overarching aims and objectives of the research project.

3. Main Body

This section focuses on explaining all aspects of your original research and so will form the bulk of your thesis. Typically, this section will contain four chapters covering the below:

• your research/data collection methodologies,
• your results,
• a comprehensive analysis of your results,
• a detailed discussion of your findings.

Depending on your project, each of your chapters may independently contain the structure listed above or in some projects, each chapter could be focussed entirely on one aspect (e.g. a standalone results chapter). Ideally, each of these chapters should be formatted such that they could be translated into papers for submission to peer-reviewed journals. Therefore, following your PhD, you should be able to submit papers for peer-review by reusing content you have already produced.

4. Conclusion

The conclusion will be a summary of your key findings with emphasis placed on the new contributions you have made to your field.

When producing your conclusion, it’s imperative that you relate it back to your original research aims, objectives and hypotheses. Make sure you have answered your original question.

Finding a PhD has never been this easy – search for a PhD by keyword, location or academic area of interest.

How Many Words Is a PhD Thesis?

A common question we receive from students is – “how long should my thesis be?“.

Every university has different guidelines on this matter, therefore, consult with your university to get an understanding of their full requirements. Generally speaking, most supervisors will suggest somewhere between 70,000 and 100,000 words . This usually corresponds to somewhere between 250 – 350 pages .

We must stress that this is flexible, and it is important not to focus solely on the length of your thesis, but rather the quality.

How Do I Format My Thesis?

Although the exact formatting requirements will vary depending on the university, the typical formatting policies adopted by most universities are:

What Happens When I Finish My Thesis?

After you have submitted your thesis, you will attend a viva . A viva is an interview-style examination during which you are required to defend your thesis and answer questions on it. The aim of the viva is to convince your examiners that your work is of the level required for a doctoral degree. It is one of the last steps in the PhD process and arguably one of the most daunting!

For more information on the viva process and for tips on how to confidently pass it, please refer to our in-depth PhD Viva Guide .

How Do I Publish My Thesis?

Unfortunately, you can’t publish your thesis in its entirety in a journal. However, universities can make it available for others to read through their library system.

If you want to submit your work in a journal, you will need to develop it into one or more peer-reviewed papers. This will largely involve reformatting, condensing and tailoring it to meet the standards of the journal you are targeting.

Browse PhDs Now

Join thousands of students.

Join thousands of other students and stay up to date with the latest PhD programmes, funding opportunities and advice.

Know the Difference: PhD Dissertation vs. Thesis

One of the biggest turning points of any PhD student’s journey is the submission of a research writing project in the form of either a PhD thesis or a PhD dissertation. From an academic perspective, the thesis/dissertation is in many ways a major indicator of the abilities and expertise that you have gained as a doctoral candidate.

The mere task of understanding the requirements and compiling a PhD dissertation/thesis is in itself huge. However, what may be confusing to understand, especially if you are just embarking upon your doctoral journey, is the difference between thesis and dissertation.

Table of Contents

Similarities in phd dissertation vs. thesis, 1. understanding differences in the meaning of the two terms, 2. difference between thesis and dissertation based upon geographical location, 3. understanding a difference in content for a phd thesis v/s phd dissertation.

These two terms are often used interchangeably when referring to doctoral studies as there are a number of similarities between them:

• The very first commonality between thesis and dissertation is that the submission of both is considered to be an official culmination of the doctoral work of the candidate.
• Both the thesis and the dissertation demonstrate the ability of a doctoral candidate to effectively communicate their process of resolving a problem statement.
• The thesis and dissertation both test a candidate’s ability toward analytical reasoning and critical thinking , while showcasing his/her expertise in a particular subject area.
• Both the thesis and the dissertation are evaluated by an official review committee consisting of internal as well as external examiners who are experts in the specific subject area being explored in the doctoral study.
• Based upon the reviews of the committee members, both of these documents are then subject to changes and re-submission as required .
• Lastly, both a thesis and a dissertation can be treated as official publications that may be available as resources in the university library .

Owing to the above-mentioned similarities, the confusion between the correct usage of dissertation vs. thesis is quite understandable. In order to ensure the proper usage of these two terms, it’s crucial to understand the differences in a PhD thesis v/s PhD dissertation. Here are some quick pointers that may be useful.

Differences between thesis and dissertation

Since most academic institutions will continue to use these terms interchangeably, it is imperative that you confirm the intricate details regarding the expected structure of a PhD thesis/dissertation with your respective institution. However, for now, we hope that the above article helps in clarifying some of the major doubts that you may have had regarding a PhD thesis v/s dissertation.

In order to better understand the meaning of thesis vs dissertation, let us go back to the origin of the terms. The term ‘thesis’ originates from the Greek word ‘tithenai’, which means ‘to place a proposition’, while the term ‘dissertation’ has a Latin origin, which essentially means ‘disserere’/’dissertare’, i.e., ‘to (continue to) examine and discuss’. 1 To simplify further, a thesis by itself may simply represent an argument that you put forth and describe in depth, while a dissertation may represent a written summary/discussion of a particular work. 2

In countries/institutions that follow the British education system, it is common to term the final doctoral research writing project as a PhD thesis, while the countries/institutions that follow the American education system prefer to call it a PhD dissertation. In case you are unsure which education system is followed by your institution, it may be a good idea to verify this with the respective personnel, so that you can plan your doctoral journey effectively.

While the above two points may be useful to understand the differences between thesis and dissertation on a surface level, as a PhD student it is crucial for you to understand the deeper differences in the content and the type of work that goes into each of them. Let us do this by revisiting the differences in the origin of the two terms: ‘dissertare’ or to discuss (dissertation) v/s ‘to place a proposition’ (thesis). In my experience, the content of a PhD dissertation often comprises peer-reviewed publications that are published by the doctoral candidate during their doctoral work, along with supplementary chapters. This is followed by a dissertation defense , an presentation by the student on the main aspects of the research reported in the dissertation. 

On the other hand, while compiling a PhD thesis, a doctoral candidate may need to describe the doctoral work in detail with the help of distinct chapters comprising: abstract, introduction, literature review, methodology, results, discussion, conclusion and bibliography/references. Thus, the main difference between thesis and dissertation, lies in the way the written document is being presented although the doctoral work done by the candidate will mostly remain the same .

References:

1.         What is the Difference Between a Dissertation and a Thesis? | Postgrad.com. https://www.postgrad.com/advice/exams/dissertation-and-theses/difference-between-a-dissertation-and-a-thesis/

2.         The PhD Thesis | FindAPhD.com. www.FindAPhD.com https://www.findaphd.com/guides/phd-thesis.

The time it takes to write a PhD thesis vs. dissertation can vary depending on several factors, including the research topic, the scope of the project, the research methodology, and the specific requirements of the academic program. However, in general, a dissertation is typically longer and more comprehensive than a thesis, and therefore may take longer to complete.

A dissertation for doctoral programs is typically required after the completion of required coursework, passing comprehensive exams, and hitting any other specific milestones outlined by the program. This means PhD students usually devote years in developing their dissertation, which demonstrates your ability to conduct independent research and make original contributions to the field

A thesis statement is used in academic writing to provide a concise summary of the main argument or point being made in an essay or paper. It should be used at the introduction at the beginning of the paper to guide the reader and provide focus for the writing. A thesis statement can be used in academic essays, research papers, analytical papers and literature reviews and presents readers with a clear roadmap of the research being conducted.

Paperpal is a comprehensive AI writing toolkit that helps students and researchers achieve 2x the writing in half the time. It leverages 21+ years of STM experience and insights from millions of research articles to provide in-depth academic writing, language editing, and submission readiness support to help you write better, faster.  

Get accurate academic translations, rewriting support, grammar checks, vocabulary suggestions, and generative AI assistance that delivers human precision at machine speed. Try for free or upgrade to Paperpal Prime starting at US$19 a month to access premium features, including consistency, plagiarism, and 30+ submission readiness checks to help you succeed.  

Experience the future of academic writing – Sign up to Paperpal and start writing for free!  

Related Reads:

• PhD Dissertation Outline: Creating a Roadmap to Success
• Scientific Writing Style Guides Explained
• How to Write a Personal Statement for a PhD Program
• How to Make Your Thesis Supervision Work for You

Duplicate Publications: How to Avoid Overlapping Publications in Research

Manuscript submission: get your pre-submission checks right with paperpal , you may also like, online ai writing tools: cost-efficient help for dissertation..., phd qualifying exam: tips for success , ai in education: it’s time to change the..., 9 steps to publish a research paper, self-plagiarism in research: what it is and how..., 6 tips for post-doc researchers to take their..., 8 most effective ways to increase motivation for..., how to make your thesis supervision work for..., how to write a conclusion for research papers..., ethical research practices for research with human subjects.

Home > Blog > Tips for Online Students > Dissertation vs Thesis: The Differences that Matter

Tips for Online Students , Tips for Students

Dissertation vs Thesis: The Differences that Matter

Updated: November 27, 2024

Published: April 26, 2020

In this article

As a graduate student, you will have many different types of challenging coursework and assignments. However, the biggest project that you’ll work on when earning your master’s or doctoral degree will be your thesis or dissertation . The differences between a dissertation vs thesis are plenty. That’s because each of these pieces of writing happen at different times in one’s educational journey.

Let’s break down what a dissertation and thesis are so that you have a strong handle on what’s expected. For both a thesis and a dissertation, there is an obvious fluency and understanding of the subject one studies.

Let’s take a look at their similarities and differences.

Photo by  Glenn Carstens-Peters  on  Unsplash

What is a dissertation.

When you enter a doctoral program to earn a PhD, you will learn a lot about how to conduct your own research. At the culmination of your degree program, you’ll produce a dissertation.

A dissertation is a lengthy piece of written work that includes original research or expanded research on a new or existing topic. As the doctoral student, you get to choose what you want to explore and write about within your field of study.

What is a Thesis?

A thesis is also a scholarly piece of writing, but it is for those who are graduating from a master’s program. A thesis allows students to showcase their knowledge and expertise within the subject matter they have been studying.

Main Differences Between a Thesis vs. Dissertation

The biggest difference between a thesis and a dissertation is that a thesis is based on existing research.

On the other hand, a dissertation will more than likely require the doctoral student to conduct their own research and then perform analysis. The other big difference is that a thesis is for master’s students and the dissertation is for PhD students.

Structural Differences Between a Thesis and a Dissertation

Structurally, the two pieces of written analysis have many differences.

• A thesis is at least 100 pages in length
• A dissertation is 2-3x that in length
• A thesis expands upon and analyzes existing research
• A dissertation’s content is mostly attributed to the student as the author

Research Content and Oral Presentation

Once completed, some programs require students to orally present their thesis and dissertation to a panel of faculty members.

Typically, a dissertation oral presentation can take several hours. On the other hand, a thesis only takes about an hour to present and answer questions.

Let’s look at how the two scholarly works are similar and different:

Similarities:

• Each is considered a final project and required to graduate
• Both require immense understanding of the material
• Written skills are key to complete both
• Neither can be plagiarized
• Both are used to defend an argument
• Both require analytical skills
• You will have to draft, rewrite, and edit both pieces of writing
• For both, it is useful to have another person look over before submission
• Both papers are given deadlines

Differences:

• A dissertation is longer than a thesis
• A dissertation requires new research
• A dissertation requires a hypothesis that is then proven
• A thesis chooses a stance on an existing idea and defends it with analysis
• A dissertation has a longer oral presentation component

The Differences in Context: Location Matters

The united states.

In the US, everything that was previously listed is how schools differentiate between a thesis and a dissertation. A thesis is performed by master’s students, and a dissertation is written by PhD candidates.

In Europe, the distinction between a thesis and dissertation becomes a little more cloudy. That’s because PhD programs may require a doctoral thesis to graduate. Then, as a part of a broader post-graduate research project, students may complete a dissertation.

Photo by  Russ Ward  on  Unsplash

The purpose behind written research.

Each piece of writing is an opportunity for a student to demonstrate his or her ability to think critically, express their opinions in writing, and present their findings in front of their department.

Graduate degrees take a lot of time, energy, and hard work to complete. When it comes to writing such lengthy and informative pieces, there is a lot of time management that is involved. The purpose of both a thesis and a dissertation are written proof that you understand and have mastered the subject matter of your degree.

Degree Types

A doctoral degree, or PhD, is the highest degree that one can earn. In most cases, students follow the following path to achieve this level of education: Earn a bachelor’s degree, then a master’s, and then a PhD. While not every job title requires this deep educational knowledge, the salaries that come along with each level of higher education increase accordingly.

Earning Your Degree

Whether you are currently a prospective student considering earning your higher education degree or a student enrolled in a master’s or doctoral program, you know the benefits of education.

However, for some, earning a traditional degree on-campus doesn’t make sense. This could be because of the financial challenges, familial obligations, accessibility, or any other number of reasons.

For students who are seeking their higher education degrees but need a flexible, affordable, and quality alternative to traditional college, take a look at the programs that the University of the People has to offer.

University of the People is an entirely online, US accredited and tuition-free institution dedicated to higher education. You can earn your Master’s in Business Administration or your Master’s in Education . Not to mention, there are a handful of associate’s and bachelor’s degree programs to choose from as well.

If you want to learn more, get in touch with us !

The Bottom Line

Regardless of where and when you earn your master’s or doctoral degree, you will likely have to complete a thesis or dissertation. The main difference between a thesis and dissertation is the level at which you complete them. A thesis is for a master’s degree, and a dissertation is for a doctoral degree.

Don’t be overwhelmed by the prospect of having to research and write so much. Your educational journey has prepared you with the right time management skills and writing skills to make this feat achievable!

At UoPeople, our blog writers are thinkers, researchers, and experts dedicated to curating articles relevant to our mission: making higher education accessible to everyone. Read More

• Icon Calendar 16 May 2024
• Icon Page 521 words
• Icon Clock 3 min read

Students at advanced levels of education have the desire to successfully write a Doctor of Philosophy (PhD) thesis. Basically, this type of writing demonstrates their expertise in a discipline. Also, it takes an extended period for the creation of a PhD paper because of its sophistication. Thus, the completion of a doctoral program is signified by a passing Ph.D. thesis, which depicts overarching interdisciplinary qualities.

The Defenition of PhD Thesis

A PhD thesis is a form of examination used for advanced degrees. For example, individuals in pursuit of doctorate degrees have to develop a thesis subjected to scrutiny by a committee of professors that judge its merit. In this case, students draft a thesis proposal that they present and defend to a select panel. After approval of the thesis proposal, the level of the panel’s participation may vary depending on the university’s PhD program structure. Then, people do not limit the length of a PhD paper. However, the author must ensure that the document contains a comprehensive exploration of a new approach. Also, the paper must contribute positively to the existing body of knowledge. Finally, a PhD work covers a clear understanding of previous studies. Thus, the doctorate is awarded after completion of a PhD paper to symbolize an individual’s mastery of content and research techniques.

All doctorate program students must write a thesis that may assume different forms depending on the PhD model. For instance, the classical PhD model is based on the development of one ‘big book’ thesis that consists of integrated chapters with a word count ranging between 80,000-100,000. Basically, this approach does not involve much coursework. However, it focuses on thesis preparation throughout the program. Then, an alternative model is the taught PhD model that entails two stages: examinable coursework and a thesis comprised of at least four medium-length publishable papers. In turn, the PhD thesis has separate papers presumed to be the equivalent of the big book thesis. As a result, the authorship appears to be an essential concept of doctoral studies.

Differences in Disciplines

There are no substantial differences between PhD thesis papers developed for specific disciplines. For example, examiners tend to search for the presence of identical core qualities of a thesis regardless of the discipline. Basically, a PhD paper should attain a certain level of coherence, originality, and academic validity for it to pass a critical examination in any discipline. However, inconsistencies may arise due to the inadequacy of institutional criteria, vagueness in the desired level of contribution to existing knowledge, and examiners’ bias for personal assessment standards. In turn, the fluidity of examiners’ expectations causes slight differences in a thesis. Also, disciplinary demands modify the nature of a PhD thesis to a small extent.

Conclusion on PhD Thesis

The completion of the PhD thesis writing process precedes the attainment of a doctorate. Basically, research and authorship are fundamental skills for any doctorate holder. In this case, a PhD paper is not discipline-specific because examiners hold nearly identical assertions concerning its qualities. Thus, the writing of a PhD thesis is a unique learning experience. In turn, people may get thesis help.

To Learn More, Read Relevant Articles

Harvard Referencing

• Icon Calendar 29 March 2020
• Icon Page 568 words

Essay on How Virtual Reality Turns Students Into Scientists

• Icon Calendar 22 March 2020
• Icon Page 794 words

What is a Ph.D. Dissertation?

[I wrote this in 1993 as a letter to a student concerning a draft of his dissertation. In 2003 I edited it to remove some specific references to the student and present it as a small increment to the information available to my grad students. In 2023 I made small edits for grammar and to expand coverage.--spaf]

Let me start by reviewing some things that may seem obvious:

• Your dissertation is part of the requirements for a PhD. The research, theory, experimentation, et al. also contribute. One does not attempt to capture everything in one's dissertation.
• The dissertation is a technical work that documents and proves one's thesis. It is intended for a technical audience and must be clear and complete but not necessarily exhaustively comprehensive. Also note -- experimental data, if used, is not the proof -- it is evidence. The proof is presented as an analysis and critical presentation. Generally, every statement in your dissertation must be common knowledge, supported by citation to technical literature, or original results proved by the candidate (you). Each of those statements must directly relate to the proof of the thesis, or else they are unnecessary.

Let's revisit the idea of the thesis itself. It is a hypothesis, a conjecture, or a theorem. The dissertation is a formal, stylized document used to argue your thesis. The thesis must be significant, original (no one has yet demonstrated it to be true), and it must extend the state of scientific knowledge.

The first thing you need to do is to come up with no more than three sentences that express your thesis. Your committee must agree that your statements form a valid thesis statement. You, too, must be happy with the statement -- it should be what you will tell anyone if they ask you what your thesis is (few people will want to hear an hour's presentation as a response).

Once you have a thesis statement, you can begin developing the dissertation. The abstract, for instance, should be a one-page description of your thesis and how you present the proof of it. The abstract should summarize the results of the thesis and should stress the contributions to science made thereby.

Perhaps the best way to understand how an abstract should look would be to examine the abstracts of several dozen dissertations that have already been accepted. Our university library has a collection of them. This is a good approach to see how an entire dissertation is structured and presented. MIT Press has published the ACM doctoral dissertation award series for decades, so you may find some of those to be good examples to read -- they should be in any large technical library.

The dissertation itself should be structured into 4 to 6 chapters. The following is one commonly-used structure:

• Introduction. Provide an introduction to the basic terminology, cite appropriate background work, and briefly discuss related work that has already covered aspects of the problem.
• Abstract model. Discuss an abstract model of what you are trying to prove. This chapter should not discuss any specific implementation (see below)
• Validation of model/proof of theorems. This is a chapter showing proof of the model. It could be a set of proofs or a discussion of the construction and validation of a model or simulation to gather supporting data.
• Measurements/data. This would present data collected from actual use, simulations, or other sources. The presentation would include analysis to show support for the underlying thesis.
• Additional results. In some work, there may be secondary confirmation studies, or it might be the case that additional significant results are collected along the way to the proof of the central thesis. These would be presented here.
• Conclusions and future work. This is where the results are all tied together and presented. Limitations, restrictions, and special cases should be clearly stated here, along with the results. Some extensions as future work may also be described.

Let's look at these in a little more detail

Chapter I, Introduction. Here, you should clearly state the thesis and its importance. This is also where you define terms and other concepts used elsewhere. There is no need to write 80 pages of background on your topic here. Instead, you can cover almost everything by saying: "The terminology used in this work matches the definitions given in [citation, citation] unless noted otherwise." Then, cite some appropriate works that give the definitions you need. The progress of science is that we learn and use the work of others (with appropriate credit). Assume you have a technically literate readership familiar with (or able to find) standard references. Do not reference popular literature or WWW sites if you can help it (this is a matter of style more than anything else -- you want to cite articles in refereed conferences and journals, if possible, or in other theses).

Also, in the introduction, you want to survey any related work that attempted something similar to your own or has a significant supporting role in your research. This should refer only to published references. You cite the work in the references, not the researchers themselves. E.g., "The experiments described in [citation] explored the foo and bar conditions, but did not discuss the further problem of baz, the central point of this work." You should not make references such as this: "Curly, Moe, and Larry all believed the same in their research [CML53]" because you do not know what they believed or thought -- you only know what the paper states. Every factual statement you make must have a specific citation tied to it in this chapter, or else it must be common knowledge (don't rely on this too much).

Chapter II. Abstract Model. Your results are to be of lasting value. Thus, the model you develop and write about (and indeed, that you defend) should have lasting value. Thus, you should discuss a model not based on Windows, Linux, Ethernet, PCMIA, or any other technology. It should be generic and capture all the details necessary to overlay the model on likely environments. You should discuss the problems, parameters, requirements, necessary and sufficient conditions, and other factors here. Consider that 20 years ago (ca 1980), the common platform was a Vax computer running VMS or a PDP-11 running Unix version 6, yet well-crafted theses of the time are still valuable today. Will your dissertation be valuable 20+ years from now (ca 2050), or have you referred to technologies that will be of only historical interest?

This model is tough to construct but is the heart of the scientific part of your work. This is the lasting part of the contribution, and this is what someone might cite 50 years from now when we are all using MS Linux XXXXP on computers embedded in our wrists with subspace network links!

Chapters III & IV, Proof.There are basically three proof techniques that I have seen used in a computing dissertation, depending on the thesis topic. The first is analytic, where one takes the model or formulae and shows, using formal manipulations, that the model is sound and complete. A second proof method is stochastic, using statistical methods and measurements to show that something is true in the anticipated cases.

• clearly showing how your implementation model matches the conditions of your abstract model,
• describing all the variables and why you set them as you do,
• accounting for confounding factors, and
• showing the results.

Chapter V. Additional results. This may be folded into Chapter III in some theses or multiple chapters in a thesis with many parts (as in a theory-based thesis). This may be where you discuss the effects of technology change on your results. This is also a place where you may wish to point out significant results that you obtained while seeking to prove your central thesis but which are not supportive of the thesis. Often, such additional results are published in a separate paper.

Chapter VI. Conclusions and Future Work. This is where you discuss what you found from your work, incidental ideas and results that were not central to your thesis but of value nonetheless (if you did not have them in Chapter V), and other results. This chapter should summarize all the important results of the dissertation --- note that this is the only chapter many people will ever read, so it should convey all the important results.

This is also where you should outline some possible future work that can be done in the area. What are some open problems? What are some new problems? What are some significant variations open to future inquiry?

Appendices usually are present to hold mundane details that are not published elsewhere but are critical to the development of your dissertation. This includes tables of measurement results, configuration details of experimental testbeds, limited source code listings of critical routines or algorithms, etc. It is not appropriate to include lists of readings by topic, lists of commercial systems, or other material that does not directly support the proof of your thesis.

Here are some more general hints to keep in mind as you write/edit:

• Adverbs should generally not be used -- instead, use something precise. For example, do not say that something "happens quickly." How fast is quickly? Is it relative to CPU speeds? Network speeds? Does it depend on connectivity, configuration, programming language, OS release, etc? What is the standard deviation?
• As per the above, the use of the words "fast," "slow," "perfect," "soon," "ideal," "lots of," and related should all be avoided. So should "clearly," "obviously," "simple," "like," "few," "most," "large," et al.
• What you are writing is scientific fact. Judgments of aesthetics, ethics, personal preference, and the like should be in the conclusions chapter, if they should be anywhere at all. With that in mind, avoid the use of words such as "good," "bad," "best," and any similar discussion. Also, avoid stating "In fact," "Actually," "In reality," and any similar construct -- everything you are writing must be factual, so there is no need to state such things. If you feel compelled to use one of these constructs, then carefully evaluate what you are saying to ensure you are not injecting relative terms, opinions, value judgments, or other items inappropriate for a dissertation.
• Computers and networks do not have knees, so poor performance cannot bring them to something they do not have. They also don't have hands, so "On the one hand..." is not good usage. Programs don't perform conscious thought (nor do their underlying computers), so your system does not "think" that it has seen a particular type of traffic. Generalizing from this, do not anthropomorphize your IT components!
• Avoid mention of time and environment. "Today's computers" are antiques far sooner than you think. Your thesis should still be true many years from now. If a particular time or interval is necessary, be explicit, as in "Between 1905 and 1920" rather than "Over the last 15 years." (See the difference, given some distance in time?)
• Be sure that any scientist or mathematician would recognize something you claim as proof.
• Focus on the results and not the methodology. The methodology should be clearly described but not the central topic of your discussion in chapters III & IV
• Keep concepts and instances separate. An algorithm is not the same as a program that implements it. A protocol is not the same as the realization of it; a reference model is not the same as a working example, and so on.

As a rule of thumb, a CS dissertation should probably be longer than 100 pages but less than 160. Anything outside that range should be carefully examined with the above points in mind.

Keep in mind that you -- the Ph.D. candidate -- are expected to become the world's foremost expert on your topic area. That topic area should not be unduly broad but must be big enough to be meaningful. Your advisor and committee members are not supposed to know more about the topic than you do -- not individually, at least. Your dissertation is supposed to explain your findings and, along with the defense, demonstrate your mastery of the area in which you are now the leading expert. That does not mean writing everything you know -- it means writing enough about the most important points that others can agree with your conclusions.

Last of all, don't fall into the trap that ties up many candidates and causes some of them to flame out before completion: your thesis does not need to be revolutionary. It simply needs to be an incremental advancement in the field. Few Ph.D. dissertations have ever had a marked impact on the field. Instead, it is the author's set of publications and products of the author that may change the field.

If your dissertation is like most, it will only be read by your committee and some other Ph.D. candidates seeking to build on your work. As such, it does not need to be a masterwork of literature, nor does it need to solve a long-standing problem in computing. It merely needs to be correct, to be significant in the judgment of your committee, and it needs to be complete. We will all applaud when you change the world after graduation. And at that, you will find that many well-known scientists in CS have made their careers in areas different from their dissertation topic. The dissertation is proof that you can find and present original results; your career and life after graduation will demonstrate the other concerns you might have about making an impact.

So get to work!