Korean high school students’ understanding of the concept of correlation

Abstract

Correlation is a basic statistical concept which is necessary for understanding the relationship between two variables when they change values. In the secondary curriculum of Korea, only in formal definition of correlation is taught with two-way data representations such as scatter plots and contingency tables in the middle school. In this study, we investigated Korean high school students’ understanding of correlation using a test consisting of 35 items about interpretation of scatter plot, contingency table, and text in realistic situation. Two hundred and sixteen students from a high school in Seoul took the test for 20 min. Most of students could tell a correlation and the direction of the correlation between two variables presented in a scatter plot. However, they exhibited the confusion between the steepness of slope and the strength of the correlation. Students had difficulties in determining the amount of association between two qualitative variables when the data are given in a 2-by-2 contingency table.