Planning Investigations: Hypothesis Formation
Formation of Hypothesis
- A hypothesis is a clear, concise, and testable statement that expresses the expected outcome or prediction for a scientific investigation.
- An effective hypothesis should be based on prior knowledge or observation.
- Hypotheses are often stated as an “If…, then…” statement that predicts the effect of one variable on another.
- The independent variable is the factor that is manipulated or changed during an experiment, while the dependent variable is the factor that is measured.
- Hypothesis should express a cause and effect relationship between the independent and dependent variables.
- The hypothesis is not the end result; rather, it guides the data collection and analysis phase of the research project.
Characteristics of a Valid Hypothesis
- It must be a testable statement—one that can give rise to measurable outcomes.
- It should identify and relate the independent and dependent variables clearly.
- It needs to be based on existing scientific knowledge.
- It should be simple and specific, using precise terminology.
- A valid hypothesis often predicts the anticipated direction of the effect.
Importance of Null Hypothesis
- The null hypothesis (H0) states that there is no relationship or effect of the independent variable on the dependent variable in the investigated population.
- It represents a statement of no difference or no association between variables and serves as the basis of comparison for testing the alternative hypothesis.
- The aim is not necessarily to prove the null hypothesis correct, but to determine whether it can be rejected or not rejected based on the evidence collected.
Alternative Hypothesis
- The alternative hypothesis (H1 or Ha) is the rival claim to the null hypothesis that we believe might be true instead.
- It proposes that there is a significant interaction or relationship between the variables studied.
- It is evaluated based on the end results; if the results provide enough evidence against the null hypothesis, the alternative hypothesis is deemed more likely.