# Activities to Teach Students to Identify an Outlier and Describe the Effect of Removing It

In statistics, an outlier is considered as a data point that deviates significantly from the other observations in a dataset. Sometimes, outliers can provide valuable insights into the data, but at times, they can also skew the results of the analysis. Therefore, it is crucial to identify and remove outliers to ensure the accuracy of statistical analysis. Teaching students the skill to identify and remove outliers can enhance their understanding of data and provide them with the tools necessary to make informed decisions.

Below are some activities that teachers can use to teach students how to identify an outlier and describe the effects of removing it.

Activity 1: Identifying Outliers

The aim of this activity is to help students identify outliers in a given set of data. Begin by providing students with a set of data that includes outliers. Ask them to calculate the mean and median of the dataset, and then highlight the outliers. Students should be able to recognize that the outliers are data points that are significantly different from other observations in the data set. This activity will provide a basic understanding of outliers and how they can affect statistical analysis.

Activity 2: Describing the Impact of Removing an Outlier

The objective of this activity is to help students understand how removing an outlier from a dataset can affect the mean, median, and standard deviation of the dataset. Begin by providing students with a dataset that includes outliers. Ask students to calculate the mean, median, and standard deviation of the dataset. Then, remove the outlier and recalculate the mean, median, and standard deviation. Students should compare the two sets of calculations and observe how the outlier has affected the statistical measures of the data set. This activity will help students recognize how the presence of outliers can affect the accuracy of statistical analysis and the importance of removing them.

Activity 3: Using Box Plots to Identify Outliers

The goal of this activity is to help students recognize outliers in a set of data using box plots. Begin by providing students with a dataset that includes outliers. Then, teach them how to create a box plot and how to identify outliers using the inter-quartile range method. Students should observe that the outliers are data points that fall outside the whiskers of the box plot. This activity will help students understand how to use box plots to identify outliers, which is a useful skill for analyzing large datasets.

Teaching students to identify outliers and describe the effects of removing them can significantly enhance their analytical skills. This knowledge will be useful for them in understanding real-world data and making informed decisions based on statistical analysis. By using these activities, teachers can help students sharpen their skills and prepare them for a future where statistical analysis has become an essential part of almost all fields.