Understanding Research Variables and Hypotheses:
Independent Variable: This is the variable the researcher manipulates or controls in an experiment to see its effect on another variable. It’s the cause or the factor being introduced to observe its impact.
Dependent Variable: This is the variable the researcher measures to see if it’s affected by the independent variable. It’s the outcome or the factor being observed for changes due to the manipulation of the independent variable.
Extraneous Variables: These are variables other than the independent variable that might also influence the dependent variable. Researchers try to control or minimize the influence of extraneous variables to isolate the specific effect of the independent variable. Imagine them as external factors that could potentially muddle the results.
Directional Hypothesis: This type of hypothesis predicts the specific direction of the relationship between the independent and dependent variables. It states whether the independent variable will increase, decrease, or have some other specific effect on the dependent variable.
Non-directional Hypothesis: This type of hypothesis predicts that there will be a relationship between the independent and dependent variables, but it doesn’t specify the direction of that relationship. It simply states that a change in one will lead to a change in the other, but not necessarily in which direction.
Null Hypothesis: This is a special hypothesis that states there is no significant relationship between the independent and dependent variables. It essentially serves as a baseline for comparison. Researchers aim to reject the null hypothesis if their data shows a statistically significant effect of the independent variable on the dependent variable.
Sample Research Hypothesis:
Area of Interest: Let’s say I’m interested in the impact of exercise on cognitive function in older adults.
Directional Hypothesis: Adults who participate in a regular exercise program (independent variable) will experience a significant improvement in their short-term memory (dependent variable) compared to adults who do not participate in a regular exercise program. (This predicts a specific direction: exercise will improve memory).
Null Hypothesis: There will be no significant difference in short-term memory function between adults who participate in a regular exercise program and those who do not. (This is the baseline hypothesis to be rejected if data shows otherwise).
