Video and Multimedia
Video Link 2.1: Correlation vs. Causation
Description: Here, Ionica Smeets explains how correlation should not be confused with causation by explaining the “dangers” of ice cream, after all, when ice cream sales go up, so do drownings. After all, correlations do not show underlying factors – like nice weather, which increases ice cream consumption, and swimming, which consequently increases drownings.
Description: In this video, the instructor walks people through identifying what the “individuals” in a data set are for any data set, even those where “individuals” does not refer to people. It also provides instruction on identifying how many variables are provided in a data set and how to identify which variables are categorical and which ones are numerical.
Video Link 2.3: Sampling
Description: Video explains what sampling is and the value of getting a representative sample using such methods as simple random sampling (where each individual has equal opportunity to be selected, and each selection is independent of the others). Systematic sampling may also be used, where samples are selected at specific, predetermined intervals (start at random point). Stratified sampling, where categories are called strata and represent a sub-population, is used when simple random sampling may not be feasible or ideal. In cluster sampling, populations are divided into clusters, which are then randomly sampled.