Skewed distributions are asymmetrical, meaning a majority of scores fall heavily on one side of the distribution. Whether or not a distribution is positive or negative is about where the fewest scores lie or the outliers -- to determine this, follow the tail.
Memory Trick (look at the I's and E's):
Positive = Tail on the right
Negative = Tail on the left
What about measures of central tendency?
Median will always be in the middle by definition.
Mode is where the most frequent scores lie – look toward the hump.
Mean is highly influenced by outliers – look at the tail! In a negatively skewed distribution, the mean will be lowest because the outliers are toward the lower end of the distribution. In a positively skewed distribution, the mean will be highest because the outliers are toward the higher end of the distribution.
Test Day Tip: Draw this image on your whiteboard when you get into the exam room and free up your brain to think through questions. You may not need it, but you’ll be ready to snap up those easy points if you get a question on skewness and measures of central tendency.