These AP Statistics NOTES WITH VIDEO will help you teach or review OBSERVATIONAL STUDIES & EXPERIMENT DESIGN! Students will define and identify explanatory variable, response variable, factor, levels, treatments, control group, and placebo in experiments. With the four Principles of Experimental Design (comparison, randomization, replication, & control), students will design experiments in PARAGRAPHS AND DIAGRAMS FOR FRQs using a completely randomized design, randomized blocking design,