Question

The paper "The Effect of Multitasking on the Grade Performance of Business Students" (Research in Higher Education Journal [2010]: 1-10) describes an experiment in which 62 undergraduate business students were randomly assigned to one of two experimental groups. Students in one group were asked to listen to a lecture but were told that they were permitted to use cell phones to send text messages during the lecture. Students in the second group listened to the same lecture but were not permitted to send text messages during the lecture. Afterwards, students in both groups took a quiz on material covered in the lecture. The researchers reported that the mean quiz score for students in the texting group was significantly lower than the mean quiz score for students in the no-texting group. In the context of this experiment, explain what it means to say that the texting group mean was significantly lower than the no-text group mean. (Hint: See discussion on page 578 )

Short answer

The phrase 'significantly lower' in this context denotes that the observed difference in mean quiz scores between the two groups is unlikely to have happened by chance. It suggests that there is a statistically meaningful difference, often driven by an underlying factor – in this case, whether or not students were allowed to send text messages during the lecture.

Step-by-step solution

Understanding the Experiment

In the experiment, 62 undergraduate business students were split into two groups. One group was allowed to text during the lecture, while the other wasn't. After the lecture, all students took a quiz, and it was reported that the texting group scored 'significantly lower' than the no-texting group.

Meaning of 'Significantly Lower'

In a statistical context, 'significantly lower' doesn't just mean that the scores were lower. It implies that given the framework of the study, the probability of observing such a difference if there actually was no difference (i.e., if texting had no impact on quiz scores) is very small. This concept is known as the p-value.

Explanation of Significance

For the mean quiz score of the texting group to be significantly lower than the no-texting group, the p-value of this outcome would need to be less than a pre-defined level, usually 0.05 (5%). If the p-value is less than this threshold, the result is deemed statistically significant, and we reject the possibility that there was no effect. In this experiment, that would mean we reject the idea that texting has no impact on students' quiz scores. Instead, we would conclude that texting during the lecture does lead to lower quiz scores.