What is hypothesis in science

Formulate scientific hypotheses for the bachelor thesis or master thesis

If you choose a empirical workto write, you need in addition to his Question at least one hypothesis. Unlike a question, a hypothesis is more of an assertion or assumption, the correctness of which has not yet been proven (Reinhold, 2000: 272). While the colloquial use of the term often means simple assumptions, when formulating scientific hypotheses one has to meet certain criteria (to distinguish the term “hypothesis” from other terms, see the Overview of the Johann Wolfgang Goethe University Frankfurt).

Formulate scientifically correct hypotheses in the bachelor thesis and master thesis

A hypothesis is always formulated with the aim of testing it logically and empirically (Reinhold 2000: 272). In order for this to be possible, a hypothesis must always meet the following criteria:

Empirical investigability

A hypothesis always describes real existing and observable facts.

This means that hypotheses can only relate to actually empirically measurable conditions. In this way, one can formulate hypotheses as to whether cars with a certain number of horsepower can drive faster than others. Because both the horsepower and the speed of a car can be measured. In addition, hypotheses about political attitudes of citizens can be formulated because they can communicate them and they can therefore be recorded. On the other hand, one cannot formulate hypotheses about the near-death experiences of the deceased. After all, there is no way to capture this empirically.


A hypothesis always refers beyond an individual case.

A hypothesis is always a so-called all-proposition. That means, it makes a statement about all elements of a certain area. For example, it claims that all birds in a given population eat poppies. A hypothesis never only relates to a single event, but always has general validity for the corresponding area. That is why one speaks of generalizability.

conditional sentences

A hypothesis must always be a meaningful conditional sentence.

At least implicitly, a hypothesis must always be an “if-then-sentence” or a “the-the-the-the-sentence”: When you step on the accelerator in cars, they accelerate. If you leave the house unclothed when it is below zero, your body temperature drops. The more horsepower a car has, the higher the maximum possible speed in km / h. The more people with high salaries move to a particular neighborhood, the more rents will rise. This means that an expected event is always linked to a condition.


You always have to be able to potentially refute a hypothesis.

A crucial factor in empirical work is that you can never verify a statement. This means that one can never conclusively and for sure know that a hypothesis is true. Because for that one would have to examine every case to which the hypothesis relates in the past and in the future and be so sure that the hypothesis always applies and will always apply. For example, one would have to look at every car that has ever been and will be built, whether there is one thing that, although more horsepower than other models, still has a lower maximum possible speed. And that is simply impossible and has to be considered.

However, one can refute a hypothesis with only one single case that contradicts the statement (unless one makes a probability statement, see: Bortz / Döring 2002: 13f), that is, if only one car with more horsepower than other models has a lower one has maximum speed than this, the general statement of the hypothesis about the relationship between horsepower and speed in cars is refuted, it is falsified.

That is why one of the most decisive criteria of scientific hypotheses is that they must be potentially falsifiable. A similar approach applies here as with empirical observability: whether a baby has memories of a previous life is simply not falsifiable because it cannot be measured. Neither can one falsify subjective descriptions: The coat of Labradors is more beautiful when they are given a certain food. “Beautiful” cannot be measured empirically and it is not possible to refute that a certain observer thinks a coat is “beautiful” (Bortz and Döring 2002: 7f).

Example of a correctly formulated hypothesis

A scientifically correct hypothesis would be, for example: The higher the horsepower of cars, the higher the maximum possible speed that you can drive with them.

This statement describes real facts that can be empirically investigated. The statement is an all-sentence and generalizes the statement to all cars. The hypothesis has the formal structure of a conditional sentence in that it is a "the-the-sentence". And you can potentially refute the hypothesis by finding a car that has a higher horsepower than others, but still has a lower maximum speed than these.

But how can you formulate formally correct but also interesting hypotheses within the framework of your own research project?

Logically derive hypotheses in the bachelor thesis and master thesis from the theory

If you want to formulate an exciting hypothesis, the focus must always be on the theme, the question and the interest in knowledge. Classically, one breaks down one's own theory into individual statements and transfers them into hypotheses.

If one obtains hypotheses in this way in order to subsequently check them empirically, one proceeds in a very classic deductive-nomological way: one derives from the theory, the general law (nomos) a phenomenon to be explained (the hypothesis), one deduces ( Bortz / Döring 2002: 20). (see a Introduction to the principle of deduction.

At this point in time, hypotheses should not yet be adequately verified. They deliberately go beyond the current state of knowledge and should, for example, go through in the following empirical investigationSurveyor a interview have yet to be checked (Bortz 2005: 108). You can get help from a professional, for example Data analysis advice or oneStatistics service.

This is where it often becomes apparent how useful your theory really is. This means that it shows whether the theory used can be broken down into logical individual statements and to what extent these work as hypotheses. In other words, whether these are statements about all real facts in a certain area, which are empirically verifiable and also at least potentially refutable and which at least implicitly have the form of conditional clauses. Otherwise the theory at hand cannot be verified empirically. If there is uncertainty here, one can too statistical advice help.

Do you want an empirical one bachelor thesis or master thesis compose or a scientific to write a book, one cannot avoid formulating hypotheses. This is the only way to empirically test your own theory and show its usefulness. If you adhere to the four criteria outlined above and consequently develop the hypotheses using a deductive-nomological approach, it is not difficult to develop good and scientifically sound hypotheses for your own empirical bachelor or master thesis.


Reinhold, Gerd (2000): Sociology Lexicon, Munich, Vienna

Döring, Nicola / Bortz, Jürgen (2002): Research methods and evaluation in the social and human sciences. 5th, completely revised and expanded Edition. Berlin, Heidelberg

Bortz, Jürgen (2005): Statistics: For human and social scientists, Heidelberg

Further reading:

Seiffert, Helmut (2003): Introduction to the philosophy of science, Vol. I, Munich.


Author: Myriel Balzer