In today’s review of confidence intervals and hypothesis tests, I was the most fuzzy on the differences between one-sided and two-sided hypothesis tests (besides the absence of R knowledge from my spring 2017 STAT 314 class). The main thing to remember between the two types of tests is where the significance region lies: does the region extend all the way to positive/negative infinity, or is the region sandwiched? This helps me remember if the alpha level must be divided by two when producing the test statistic and consequently, multiplied by two when comparing to the P-Value. As I get up to speed in R, having this solid conceptual foundation will make coding more meaningful and understandable.