Difference Between a Thesis and a Dissertation

Although the words ‘dissertation’ and ‘thesis’ are often used interchangeably, they are nevertheless, quite different and unique in their own regard when used in the field of academic research. If you are considering continuing your education after obtaining a Bachelor’s degree, knowing similarities and differences between a dissertation and a thesis might be of use.

The confusion surrounding these two terms is largely because both of them take the form of a critically written piece of academic research submitted by students graduating from a higher education programme. Both pieces of research work have the same purpose, which is to allow students to demonstrate their knowledge, skills, and expertise within the selected subject matter that they have been studying. They are both considered the final projects and have a similar structure and format. Nonetheless, there are certain differences that you should be aware of to correctly and appropriately use both terms.

Differences in Meaning

An important reason why we often confuse the two terms is that their meaning may differ across countries. For instance, in the US, students are required to do a thesis to get a Bachelors or Master’s degree and to write a dissertation at the end of a PhD programme. In the UK, on the other hand, a dissertation is written at the end of an Bachelor or Master’s programme, whereas the completion of a doctoral programme requires the completion of a thesis.

Type of Academic Work

To make things even more confusing, the type of academic work you are doing also determines whether you are completing a thesis or writing a dissertation. Students who are doing a thesis are involved in the production of an original body of research, whereas writing a dissertation often involves the review of the broad reading with the aim to demonstrate students’ understanding of what they have learnt.


When writing a thesis, researchers are expected to contribute to the existing body of literature by researching a new topic and finding an area of research that lacks evidence or is completely new. A thesis is seen as an opportunity for the researcher to suggest new theories and contribute new information to what is already known about the studied phenomenon. On the other hand, writing a dissertation is largely about ensuring that the researcher has knowledge about the subject matter.


The purpose of a dissertation is to help the researcher present the existing and learnt information, which means that the originality level of dissertations is not very high. On the contrary, a thesis is written with the purpose to develop a unique concept and vision and defend them using both theoretical and practical results.


The volume of work, which goes into writing a PhD project is substantially larger as compared to a dissertation. That is why a thesis can easily exceed 60,000 words, depending on the specific university requirements and subject. In turn, a dissertation is a much shorter piece of academic writing that usually ranges between 10,000 and 20,000 words. Typically, a thesis takes approximately three years while writing a dissertation can take a span of 3-10 months.

Although dissertations and theses have certain differences, writing a dissertation/thesis is a challenging task that requires highly developed skills and great abilities in different fields, including critical thinking, critical writing, knowledge in the topic, and practice. It also requires a significant amount of planning, effort, and time, which can be daunting. If you feel like this task is too challenging and complicated to undertake on your own, getting help from a professional thesis and dissertation writing service can be a good idea.