Human Growth and Development

Methods of Causal Inference Causal inference is the process of identifying cause-and-effect relationships between variables. Researchers use experiments to study how one variable influences another. Experimental Method Experiments are a scientific research method used to find causal relationships. They help researchers understand how one variable (cause) affects another (effect) by controlling other factors that could influence results. Key Concepts in Experiments 1.​ Independent Variable (IV): The variable that the researcher changes or manipulates . ●​ Example: A scientist changes the amount of sleep a group of students gets before a test. 2.​ Dependent Variable (DV): The variable that is measured to see if the IV had an effect. ●​ Example: The students’ test scores after different amounts of sleep. 3.​ Control Group: A group of participants that does not receive the independent variable’s change. ●​ Purpose: Serves as a baseline for comparison. ●​ Example: In a study on sleep and test scores, the control group might get their usual sleep, while the experimental group has less or more sleep. 4.​ Controlled Setting: Experiments are often done in labs or controlled environments to reduce extraneous variables (other factors that could affect results). ●​ Example: If studying sleep and test scores, researchers control lighting, noise, and distractions in the study environment. Example: Does the amount of physical activity affect children’s cognitive performance? Hypothesis: Increasing the amount of daily physical activity will improve children’s memory and concentration skills. Independent Variable (IV): The amount of physical activity children engage in (e.g., 0 minutes, 30 minutes, 60 minutes per day). ●​ This is manipulated by the researcher to observe the impact on cognitive performance. Dependent Variable (DV): Children's cognitive performance, measured through standardized memory and concentration tests (e.g., score on a working memory task or attention span during a task). ●​ This is the outcome being influenced by changes in the amount of physical activity.

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