The Influence of Information Added to Data

We conducted a study to investigate the influence of a context on students’ evaluation of data. Participants were given two data sets with the same mean but different standard deviations. Then they were asked which data set they thought was “better.” Later, participants saw the same data sets again but now embedded in a context. Again, they had to choose the “better” method. Students’ choices did not change significantly with additional information. However, when asked to justify their decision, the quality of the responses decreased when context was added. Further, 2/3 of the participants who based their decision on data justified their choice by referring to the standard deviation even though only 1/3 had sound knowledge about standard deviation.