A Level Psychology OCR Practice Exam

Which term describes a graph that is non-symmetrical?

1. Normal

2. Skewed

3. Uniform

4. Bimodal

The correct answer is: Skewed

A graph that is non-symmetrical is aptly described as skewed. In statistical terms, skewed distributions have one tail that is longer or fatter than the other, indicating that the data values are not evenly distributed around the mean. This non-symmetry results in a shift in the central tendency, either to the left or the right, depending on whether the skew is negative or positive, respectively. In contrast, a normal distribution is characterized by its symmetrical bell shape, where data values cluster around a central value, and the tails on either side extend equally. Uniform distributions are those where all outcomes are equally likely, resulting in a flat graph rather than a skewed one. Bimodal distributions have two distinct peaks, indicating that there are two different modes in the data set, but they do not necessarily imply non-symmetry. Thus, the term that accurately represents a non-symmetrical graph is skewed.