Deterministic and Random Experiment


By experiment we mean an act of conducting a controlled test or investigation.

The experiment results in something.

The possible results of an experiment may be one or more.

Based on the number of possible results in an experiment, we classify the experiments into two as

  • Deterministic and
  • Probabilistic

Deterministic Experiment

The Experiments which have only one possible result or outcome i.e. whose result is certain or unique are called deterministic or predictable experiments.

The result of these experiments is predictable with certainty and is known prior to its conduct.

This approach stipulates that the conditions under which the experiment is conducted would determine its result.

Eg : The experiments that we conduct to verify the laws of science or established laws of other areas are the best examples for these.

  1. An Experiment conducted to verify the Newton's Laws of Motion.
  2. An Experiment conducted to verify the Economic Law of Demand.

Probabilistic Experiment

Experiments whose result is uncertain are called indeterministic or unpredictable or Probabilistic experiments.

There are more than one possible results or outcomes.

The actual result in a particular conduction of the experiment would be one of those possible results.

Whatever may be the conditions under which we conduct the experiment, we can only say that the result would be one of the possible results. We cannot ensure a certain result by performing the experiment under certain conditions in a certain method.

The quantitative measure of certainty regarding one or more outcomes of these experiments is what we call "Probability".

Random Experiment

at Random

  • Without giving preference or priority to any case i.e. without any bias for any case.
  • Lacking any definite plan or order or purpose; governed by or depending on chance

An Experiment whose result is uncertain i.e. a random experiment is a probabilistic experiment. The experiment results in two or more outcomes. The result/outcome of the experiment would be one of the possible outcomes. It cannot be predicted prior to its conduct.

The different possible outcomes of the experiment can be known or assessed. But it would not be possible to predict the occurrence of a particular outcome at any particular execution of the experiment.


  • The Experiment of tossing a coin

    There are two possible outcomes i.e. getting a Head or a getting a Tail. Though we know the two possible outcomes, we cannot for sure predict that we can get a tail if we throw the coin in a particular manner and so on.
    obverse side
    Coin Obverse
    reverse side
    Coin Reverse
  • The Experiment of rolling a die

    There are six possible outcomes i.e. the die showing up 1, the die showing up 2, ... , the die showing up 6.
    Die/Dice Six Faces
    Six Faces of a Dice

    Though we know the six possible outcomes, we cannot for sure predict that we can make a particular number appear on the face of the dice if we throw/roll it in a particular manner and so on.