What Is Normal Distribution? What Is Skewed Distribution?

When the range of scores is widespread, it is more meaningful to reduce data into the smaller number of groups. These are then called grouped scores. It is easier to plot grouped scores on a graph in the form of 'class intervals'. Depending on the nature of data, various shapes of frequency distribution can be observed in the statistical graph. These distributions can be 'normal' and skewed', J-shaped, U-shaped, bow-shaped; bimodal or multimodal.

Normal Distribution looks symmetrical in the dispersion with the largest frequencies in the middle scores and tapering down of frequencies towards the highest as well as the lowest scores. One distinct feature of normal distribution is that mostly all the indications of central tendencies as mean, median and mode are the same in value.

Skewed Distribution is asymmetrical in dispersion, as skewness means lopsidedness of frequencies across scores. Distributions can be either negatively skewed or positively skewed.