Step 5: Hypothesis Statement
(will be worked on in class prior to due date)
Your hypothesis statement will be turned in during science class, reviewed by the teacher and returned. Below is a short explanation of a hypothesis statement and some examples of hypothesis statements.
Hypothesis statement--a prediction that can be tested or an educated guess.
In a hypothesis statement, students make a prediction about what they think will happen or is happening in their experiment. They try to answer their question or problem.
Question: Why do leaves change colors in the fall?
Hypothesis: I think that leaves change colors in the fall because they are not being exposed to as much sunlight.
Hypothesis: Bacterial growth may be affected by temperature.
Hypothesis: Chocolate may cause pimples
All of these are examples of hypotheses because they use the tentative word "may." However, their form in not particularly useful. Using the word does not suggest how you would go about proving it. If these statements had not been written carefully, they may not have been a hypotheses at all.
A better way to write a hypotheses is to use a formalized hypotheses
Example: If skin cancer is related to ultraviolet light, then people with a high exposure to uv light will have a higher frequency of skin cancer.
Example: If leaf color change is related to temperature, then exposing plants to low temperatures will result in changes in leaf color.
Example: If the rate of photosynthesis is related to wave lengths of light, then exposing a plant to different colors of light will produce different amounts of oxygen.
Example: If the volume of a gas is related to temperature, then increasing the temperature will increase the volume.
These examples contain the words, if and then. Formalized hypotheses contain two variables. One is "independent" and the other is "dependent." The independent variable is the one you, the scientist control and the dependent variable is the one that you observe and/or measure the results.
The ultimate value of a formalized hypotheses is it forces us to think about what results we should look for in an experiment.
Example: If the diffusion rate (dependent variable) through a membrane is related to molecular size (independent variable), then the smaller the molecule the faster it will pass through the membrane.
Hypotheses are helpful if your dissertation involves determining whether a specific prediction about the relationship between variables is correct. They often take the place of sub-questions.
Example of a hypothesis
First-year students are more likely to attend lectures than second-year students.
Using hypotheses in your dissertation
If your dissertation includes hypotheses, bear the following tips in mind.
1. Remember that the main question should not be a hypothesis
The main research question itself is usually a “normal” research question, which hypotheses are then formulated to help answer. Hypotheses therefore take the place of sub-questions.
2. Conduct preliminary research
A hypothesis is a statement about what you believe is true. To make an informed statement, you thus first need to do some research. Focus on the literature that you use for your introduction and problem statement.
3. Create a conceptual framework
Use your research as the basis for creating a conceptual framework in which you illustrate what you expect to find when you conduct the actual investigation.
4. Formulate your hypotheses
You can then derive your hypotheses from what you have presented graphically in your conceptual model. Each hypothesis will eventually be discussed in a separate chapter of your dissertation.
5. Test your hypotheses
The next step is to test your hypotheses to see if your expectations are correct or incorrect. If they are correct, the hypothesis is said to be verified (or confirmed); if not, the hypothesis is said to be falsified (or rejected).
Both null hypotheses (H0) and alternative hypotheses (H1) must be created to facilitate the testing.
Examples of null and alternative hypotheses
H0: There is no relationship between sex and aggression.
H1: There is a relationship between sex and aggression.
H0: Income has no effect on buying behavior.
H1: Income has an effect on buying behavior.
H0: There is no difference in language between older and younger people.
H1: There is a difference in language between older and younger people.