PP1.3 Lock2.pptx - Section 1.3 Experiments and...

This preview shows page 1 - 11 out of 54 pages.

Statistics: Unlocking the Power of Data Lock 5 Section 1.3 Experiments and Observational Studies
Statistics: Unlocking the Power of Data Lock 5 Outline Association versus Causation Confounding Variables Observational Studies vs Experiments Randomized Experiments
Statistics: Unlocking the Power of Data Lock 5 Review To estimate the proportion of students who support a smoke-free campus, you compute the proportion that say yes after responding to an email sent to all students asking “Do you support a smoke-free campus?” The data collected is a) Not biased b) Biased because of wording bias c) Biased because asked over email instead of in person d) Biased because responses may be inaccurate e) Biased because volunteer samples are almost always biased
Statistics: Unlocking the Power of Data Lock 5 DATA Data Collection and Bias Population Sample TODAY
Statistics: Unlocking the Power of Data Lock 5 Association and Causation Two variables are associated if values of one variable tend to be related to values of the other variable Two variables are causally associated if changing the value of the explanatory variable influences the value of the response variable
Statistics: Unlocking the Power of Data Lock 5 Causal Association? The wording of this headline implies… a) Association (not necessarily causal) b) Causal Association This implies that exercising daily will improve (change) your mental performance “Daily Exercise Improves Mental Performance”
Statistics: Unlocking the Power of Data Lock 5 Causal Association? The wording of this headline implies… a) Association (not necessarily causal) b) Causal Association This implies that eating fiber will cause you to lose weight. “Want to lose weight? Eat more fiber!”
Statistics: Unlocking the Power of Data Lock 5 Causal Association? The wording of this headline implies… a) Association (not necessarily causal) b) Causal Association There is no claim that owning a cat will change your education level. “Cat owners tend to be more educated than dog owners”
Statistics: Unlocking the Power of Data Lock 5 Association and Causation ASSOCIATION IS NOT NECESSARILY CAUSAL! Come up with two variables that are associated , but not causally Come up with two variables that are causally associated Which is the explanatory variable? Which is the response variable?
Statistics: Unlocking the Power of Data Lock 5 College Education and Aging “Education seems to be an elixir that can bring us a healthy body and mind throughout adulthood and even a longer life,” says Margie E. Lachman, a psychologist at Brandeis University who specializes in aging. For those in midlife and beyond, a college degree appears to slow the brain’s aging process by up to a decade, adding a new twist to the cost-benefit analysis of higher education — for young students as well as those thinking about returning to school.” Are you convinced that a college degree slows the brain’s aging?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture