An experiment is normally intended to test a hypothesis. Is there a noun or phrase to describe an experiment with no hypothesis -- i.e. doing something just to 'see what happens'?

(A convincing neologism would be acceptable: e.g. exploriment)

EDIT: It's been pointed out that one can think of some generalised hypothesis ('something interesting will happen') for any experiment. So to refine the question a bit: what's an experiment without a specific hypothesis?

EDIT2: Thanks for the helpful suggestions so far, which have clarified things, although sadly none have nailed it for me yet: perhaps English doesn't have a word with the connotation I'm looking for.

However I'm surprised that some of the answers have implied that there's something trivial, invalid or unscientific about experimenting without a testable hypothesis: i.e. it's "just playing about" or "just demonstration". This made me think about three types of experiment:

(A) I do something (heat water) to test a specific hypothesis (does water boil at 100°C?); 
(B) I do it to measure a property (what temperature does water boil at?); 
(C) I do it to observe what occurs (let's see what happens if I heat this water...).

These all seem to me to be very valid and scientific, but English doesn't seem to specifically distinguish between them. This post has turned out to be a very interesting experiment!

  • If you are trying to find out what happens then you are experimenting. Your hypothesis is that something will happen (at the very least). There is no distinction between an interesting hypothesis and a one that implies you've done no prior research. Commented Aug 11, 2011 at 9:11
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    In short: you are not experimenting if you do not want to find something out. Commented Aug 11, 2011 at 9:22
  • I agree: but it's a question of whether the domain of what you want to find out is open (exploration) or closed (testing). Commented Aug 11, 2011 at 9:31
  • So you are asking a question when you already know the answer: exploratory experiment. Commented Aug 11, 2011 at 9:42
  • You might also look at en.wikipedia.org/wiki/Exploratory_research
    – Unreason
    Commented Aug 11, 2011 at 12:39

11 Answers 11


This should be a comment, but it will run long. Here's what you note

However I'm surprised that some of the answers have implied that there's something trivial, invalid or unscientific about experimenting without a testable hypothesis: i.e. it's "just playing about" or "just demonstration".

Let me try to explain why there is a problem with a scientific experiment that has no hypothesis.

Assume you are going to do action A to 'see what happens' as a scientific experiment.

There are two possible outcomes:

a) nothing happens
b) X and Y occurred after A

Both outcomes are described incompletely (not scientifically).

In case of a), let us assume that we want to repeat the experiment. To do that, and to arrive at the same result one must know what was observed. However, once you define what you are observing (and how) you have effectively defined a hypothesis.

Similarly, in the case of b), if you do not specify if you were observing for event Z (obviously you were observing if X and Y would occur), the experiment can not be repeated (might yield different results), so the results can not be taken as scientific.

For the results of the experiment to be scientific I think you need repeatability, which must include the definition of the hypothesis and the testing method.

If none is given it is definitively not clear how were you testing (i.e. testing for anything will be different for different people). Therefore I support the opinion that you are not talking about an experiment.

However, as long as you can describe what you were doing (and it was controlled), you can extract the hypothesis that you were effectively testing and turn the experiment into formal one.

If your test was not controlled then it was an accident, as per original Bacon's definition.

You might want to read upon this article, too (do check the references though). Maybe research is better suited in this case.

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    I think Exploratory Research is the best answer, so I'm accepting your 'comment'. Commented Aug 13, 2011 at 13:36

Maybe you need to expand your understanding of hypothesis a little bit.

If you are doing something just to see what happens, then your hypothesis could be "something detectable will happen" or possibly "the resulting data will demonstrate a meaningful pattern".

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    Thanks, and you're right - but this isn't a helpful answer! I'm looking for a word to evoke the distinction between experiments with and without a specific hypothesis. Commented Aug 10, 2011 at 19:33
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    @Richard The word experiment implies that something specific and well planned is being done. I've suggested the word investigation in a different answer, but that implies a bigger more general process than just an experiment.
    – jimreed
    Commented Aug 10, 2011 at 19:58
  • This doesn't really answer the question. It is more of a comment. A very good comment, but not an actual response to the original question. Commented Aug 11, 2011 at 2:52

One rather dreary quote on a page about scientific experiments said

Any laboratory procedure you follow without a hypothesis is really not an experiment. It is just an exercise or demonstration of what is already known.

You might call an experiment without a hypothesis a scientific demonstration. The Wikipedia article explains:

A scientific demonstration is a scientific experiment carried out for the purposes of demonstrating scientific principles, rather than for hypothesis testing or knowledge gathering (although they may originally have been carried out for these purposes).

Some famous demonstrations that are mentioned are:

  • Al-Biruni's reaction time
  • Alhazen's camera obscura, lamp experiment and magnifying lens
  • Al-Jazari's crankshaft, elephant clock and programmable robots
  • Avenzoar's parasites
  • Detonating a cloud of flour
  • Foucault's pendulum

You could say one was just fooling around in the lab. For a much less serious phrase, I would look at the term (informal and may be construed as offensive) futz:

: fool around 1 —often used with around. futz around without producing any worthwhile music — John Koegel

If you wanted to describe just walking into a lab and seeing what happened, you could say:

On my day off I spent some time in the lab. I didn't have any projects, so I was just futzing around with pulleys to see what would happen.

Edit: One more serious option, as brought up by both @Richard and @Jay: scientific exploration. This brings to mind someone in a lab trying various things out in order to "see what happens". If your purpose is to be more formal, I would use this term. If you are, however, joking about playing around in a lab, I would still use "futzing".

  • +1 for futz, but I disagree with demonstration: that suggests an expected outcome (i.e. a hypothesis), whereas I'm thinking of an exploration where the outcome is unknown. Commented Aug 10, 2011 at 19:14
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    @Richard -- I think you just answered your own question -- I was about the answer "explore" or "exploration" :-)
    – Jay Elston
    Commented Aug 10, 2011 at 19:32

I know your question is about scientific hypotheses in general. But in the domain of software testing, a test case proceeds as a scientific experiment. You have a hypothesis, i.e., that under certain circumstances the software will behave in the specified manner, and you exercise the system and observe the output in order to prove or disprove that hypothesis (making the test "pass" or "fail", respectively).

But sometimes, testers execute test cases without any particular hypothesis, either for learning purposes or to refine the quality of the tests. This is called exploratory testing.

  • There is also the "user acceptance testing" phase to consider. I'm not sure if the hypothesis there is that the software is thought to be fully-functional and they shouldn't find any problems, or that only the really evil bugs remain (so we'll send in our top investigators to hunt them down). Commented Aug 11, 2011 at 1:14
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    @FumbleFingers, I'm not sure if I understand your comment correctly, but a "user acceptance test" is not necessarily exploratory in nature. See the concept of "User Acceptance Test Driven Development", in which each test (even from the user perspective) is actually a well defined script with inputs and expected outputs. And most of them produce binary, pass/fail results. Commented Aug 11, 2011 at 1:57
  • I'm sure there are procedures involving the words "user" and "test" that do involve formal definitions of every aspect of the user interface and functionality being tested. But in reality those users are just testers working for the customer, not the supplier. You have to allow that not all software is so rigorously tested, and often there's at least a final phase where people just "use" the new stuff, and bugs might get found then. Commented Aug 11, 2011 at 2:07
  • I'm inclined to agree with Otavio. I did user-acceptance testing. It was part of the software development life cycle. I also happened to be the person who proposed the concept and proto-typed the application. But all software I've done user-acceptance testing for has been internal use only, at very large companies. And @FumbleFingers I just realized that I'm getting rather far afield for English.stackexchange! Sorry! Commented Aug 11, 2011 at 2:47

By any rational definition, an experiment without a hypothesis is an oxymoron.

There is, as @jimreed says, the "minimal" hypothesis, something interesting will happen. But quite frankly by then you've stretched the meaning of "experiment" to breaking point. Now it's just playing about.

  • I was going to provide the very same answer: "Playing around" or "playing about". Commented Aug 11, 2011 at 2:50
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    +1 for play, but I disagree that 'an experiment without a hypothesis is an oxymoron', see Edit2 to my question. Commented Aug 11, 2011 at 9:06

In Psychology there's a term that might be helpful:

• the "Inductive Approach" is when you carry out an experiment without a hypothesis with the intention of generating a new theory from the data.

It's the opposite of the "Deductive Approach" which is where you test a current theory by creating hypotheses and seeing if the results support them.

  • Georgia, this might be a fine answer. It does need citations for the information supplied. I think you should edit, and include reliable sources to verify your information. Thanks.
    – J. Taylor
    Commented Nov 27, 2018 at 19:35

You could conduct an investigation into the behavior of a physical system. That suggests that you probably don't know everything you will try when you begin, you may not have a guess as to what you will learn, and you may follow multiple paths along the way.


You cannot conduct an experiment without a hypothesis because a hypothesis is necessary in order to know what to measure.

Lets say you just heated up some water in a closed container and at a specific temperature and pressure it became conductive or weakly magnetic. If you were not measuring temperature, pressure, conductivity and magnetism you might think that nothing had happened.

Without a hypothesis your "experiment" is certainly completely unscientific.


Very interesting question! I'm Italian and I'm asking the same question; I think that "experiment" must be intended in the broadest sense because of its importance in science. Therefore experiment is both

  • test an hypothesis (like Sir Eddington did with Einstein's relativity) and
  • make a controlled experience to get new information (just like Eratosthenes when he measured the Earth circumference; he didn't have any "hypothesis" for that)

From a quick search on Britannica online: "an operation or procedure carried out under controlled conditions in order to discover an unknown effect or law, to test or establish a hypothesis, or to illustrate a known law".


While it might still have connotations of "triviality" that you seem to wish to avoid, I cannot believe that no-one has suggested tinkering, as this is almost exactly what I would use this word to mean.



Those who contend that you must have a hypothesis in order to conduct an experiment are just bending the words to mean what they want, in disregard of how the English language is actually used.

Real World Example

Back in the ’80s I supervised a PhD student in my laboratory determining the DNA sequence of a particular virus gene (and some others). He spent three years working in the lab to do this.

Was this an experiment (or a series thereof)?

It was an attempt to do something that had not been done before. It involved laboratory procedures which in common parlance are called experimental procedures. It involved initiative and thought to overcome the problems that arose in obtaining suitable clones for sequencing. Ask anyone in the (English-speaking) biochemistry department and they will tell you he was conducting experiments. And that’s how we treat language on this site, isn’t it? Not what someone who has never been in lab has written in a dictionary.

Did he have a hypothesis?

We had no idea what the sequence would be or what it would tell us about the virus. So if you ask any scientist in our lab he would say, he/we did not have a hypothesis. Of course, you can argue that our hypothesis was that the gene had a sequence, or that if he adopted a particular strategy he would be able to prepare a clone, or that the sequence would be of interest. But that’s casuistry.

And his work was deemed worthy of a PhD, and produced information which was he subjected to analysis, producing hypotheses to test in future. So we were not just playing.

So you can ignore the real world and continue to define an experiment as something that tests a hypothesis. But why would you want to do that?

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