Planning Research Variables
Every psychology experiment revolves around variables - the things you change, measure, and try to control. Getting these right from the start determines whether your research will actually prove anything useful.
The independent variable (IV) is what you deliberately change or manipulate to see what happens. Think of it as the cause you're testing - like comparing how boys versus girls perform on a memory test. When you operationalise your IV, be crystal clear about your groups or conditions (e.g., "gender: male participants vs female participants").
The dependent variable (DV) is what you measure to see if your IV actually made a difference. This is your effect or outcome. Always operationalise your DV by starting with phrases like "score on..." or "number of..." - you need something you can turn into actual numbers for analysis.
Extraneous variables (EVs) are the sneaky factors that could mess up your results. These include environmental stuff (temperature, noise, time of day), participant differences (age, personality), and experimenter effects (tone of voice, instructions). Standardisation means keeping these EVs identical across all conditions so they can't interfere with your results.
Key Point: Poor variable control = unreliable results that other researchers can't replicate!