Hypothesis and Prediction

Observation

The first step in the scientific method process is to observe something you wish to understand, learn from, or ask a question you would an answer to. This can be something general or as specific as you like.

Once you've decided on a topic, you will need to research it thoroughly using existing information. You can collect data from books, academic journals, textbooks, the internet and your own experiences. You could even carry out an informal experiment of your own!

Figure 1 - When researching your topic, use as many resources as possible to build a solid foundation of knowledge, unsplash.com

What is the Definition of a Hypothesis?

After researching your topic using existing data and knowledge, you will write a hypothesis. This statement should help to answer your simple question.

Your hypothesis should be based on a robust scientific rationale supported by the background research conducted in the first step using the scientific method.

An Example of a Hypothesis in Science

During the observation stage, you discovered that temperature could affect the rate of a chemical reaction. Further research determined that the rate of reaction is faster at higher temperatures. This is because molecules require energy to collide and react with each other. The more energy there is (i.e., the higher the temperature), molecules will collide and react more often.

A good hypothesis could be:

‘Higher temperatures increase the rate of reaction because the particles have more energy to collide and react.’

What is the Definition of a Prediction?

Predictions assume that your hypothesis is true.

An Example of Prediction in Science

As a continuation of the example we are using in this article. A good prediction could be:

'If temperatures are increased, then the rate of reaction will increase.'

The independent variable would be the temperature. Therefore the dependent variable is the rate of reaction - this is the outcome we are interested in, and it depends on the first part of the prediction (the independent variable).

The Relationship and Difference Between Hypothesis and Prediction

Hypothesis and prediction are two different things, but they are frequently confused.

Both are statements assumed to be true, based on existing theories and evidence. However, there are a couple of key differences to remember:

• A hypothesis is a general statement of how you think the phenomenon works.

• Meanwhile, your prediction shows how you will test your hypothesis.

• The hypothesis should always be written before the prediction.

  Remember that the prediction should prove the hypothesis to be correct.

Gathering Evidence to Test the Prediction

The purpose of an experiment is to gather evidence to test your prediction. Gather your apparatus, measuring equipment and a pen to keep track of your results!

Accepting or Rejecting the Hypothesis

The conclusion shows the results of the experiment - have you found evidence to support your prediction?

• If your results match your prediction, you accept the hypothesis.

• If your results don’t match your prediction, you reject the hypothesis.

Remember that a hypothesis is an explanation for why something happens. The hypothesis is used to make the prediction - the outcome you would get if your hypothesis is true.

^{1. CGP, GCSE AQA Combined Science Revision Guide, 2021}

^{2. Jessie A. Key, Factors that Affect the Rate of Reactions, Introductory Chemistry - 1st Canadian Edition, 2014}

^{3. Neil Campbell, Biology: A Global Approach Eleventh Edition, 2018}

^{4. Paul Strode, The Global Epidemic of Confusing Hypotheses with Predictions Fixing an International Problem, Fairview High School, 2011}

^{5. Science Made Simple, The Scientific Method, 2019}

^{6. Trent University, Understanding Hypotheses and Predictions, 2022}

^{7. University of Massachusetts, Effect of Temperature on the Reactivity of Magnesium in Water, 2011}