22. Stankiewicz and colleagues (2006) examined how limitations in human perception and memory (and other factors) affect people’s ability to find their way in indoor spaces. In one of their experiments, eight students used a computer keyboard to move through a virtual indoor space of corridors and hallways shown on a computer monitor. The researchers calculated how efficiently students moved through the space, with efficiency ranging from 0 (extremely inefficient) to 1 (extremely efficient).

The researchers compared the efficiency of moving through the space when students had a limited view of the space versus when they had a clear (or unlimited)

view of the space. Their results are shown in Figure 14. In the figure caption, they note that “Error bars represent 1 standard error of the mean.” Explain the meaning of this statement, using one of the error bars as an example, to a person who understands mean and standard deviation, but knows nothing else about statistics.