Types of studies | AP Statistics | Khan Academy

Keep going! Check out the next lesson and practice what you’re learning:<br> <a target="_blank" rel="nofollow noopener noreferrer" href="https://www.khanacademy.org/math/ap-statistics/gathering-data-ap/sampling-observational-studies/v/worked-example-identifying-observational-study">https://www.khanacademy.org/math/ap-statistics/gathering-data-ap/sampling-observational-studies/v/wo...</a><br> <br> Sal distinguishes between experiments and observational studies, and further describes types of observational studies: retrospective, prospective, and sample surveys.<br> <br> View more lessons or practice this subject at <a target="_blank" rel="nofollow noopener noreferrer" href="https://www.khanacademy.org/math/ap-statistics/gathering-data-ap#sampling-observational-studies">https://www.khanacademy.org/math/ap-statistics/gathering-data-ap#sampling-observational-studies</a>