Writing a Hypothesis

Writing a Hypothesis

The most common way a hypothesis is used in scientific research is as a tentative, testable, and falsifiable statement that explains some observed phenomenon in nature. For your project, you will write a hypothesis and a prediction.

The hypothesis statement can be followed by the specific, measurable prediction you can make if the hypothesis is valid. Thus, we can think of the hypothesis in science as an explanation or generalization on trial. You may develop a hypothesis like: “It is hypothesized that obedience to classroom rules has an indirect relationship to the students’ age and level of morality.” OR “Obedience declines as higher stages of morality are reached.”

A prediction in science is a prophecy, a specific and measurable event that is likely to happen in the future as the result of an experiment if the hypothesis is valid. This can be written as an “if, then, because…” statement. Example: “If 2nd graders are more likely to be obedient, then the instances of obedience will be significantly higher than observed in 9th graders because 2nd graders are in Kohlberg’s conventional stage of morality and want to be recognized for good behavior.”

**You may recognize a prediction as the way you’ve been taught to write a hypothesis in the past. Please make sure you can differentiate between these two statements.**

Here are some examples of incorrectly and correctly written hypotheses:

Incorrect / Correct
If a plant receives fertilizer, then they will grow to be bigger than a plant that doesn’t receive fertilizer. / It is hypothesized that the structural and functional integrity of the system as a whole is dependent on nerve activity.
I believe resin content of various pine species will affect its energy output. / The foraging patterns ofS. carpocapsae, as measured by directional response, are affected by electrical fields.
It is hypothesized that a forefoot strike pattern will correlate with lower ground reaction forces. / Aspirin inhibits key oncogenic factors and/or activates pivotal tumor suppressor genes.
If food is present in the aquarium, then snails will move with greater speed (toward the food) (Green 2004). / Marsh grass growth is limited by available nitrogen (Miller and Levine 2010).
If the farmer burns the prairie then the next year will produce taller plants in his field then the previous year. / The fire is replenishing the nutrients in the soil.
We aimed to test the hypothesis of whether young healthy women will increase muscle mass and lose fat mass after undergoing 12 wk of intense resistance training (Josse et al. 2010). / Based on this observation, we hypothesized that natural selection may have influencedAMY1copy number in certain human populations (Perry et al. 2007).

You can read more about developing hypotheses and predictions here:

You will also develop a null hypothesis.

The null hypothesis is a hypothesis which the researcher tries to disprove, reject or nullify. The 'null' often refers to the common view of something, while the hypothesis is what the researcher really thinks is the cause of a phenomenon. An experiment always refers to the null, rejecting or accepting. Your null hypothesis usually states that there is no relationship between the variables you are testing.

Write a hypothesis, prediction and null hypothesis for your project based on your background research.