school students to take a 20-item numeric IQ test and randomly assigned them to one of two experimental conditions. In one condition, a large red rectangle appeared on the cover page of the test. In the other condition, the rectangle was a gray color. The results are shown in Figure 5-15, which includes standard error bars. Explain what the standard error bars mean, using one of the error bars as an example, to a person who understands mean and standard deviation, but knows nothing else about statistics. (You may be interested to know that the results supported the researchers' hypothesis: Students who viewed the red rectangle solved fewer of the IQ items than students who viewed the gray rectangle.) answer

ab 23. Maier and colleagues (2008) conducted a study to examine whether the perception of the color red can adversely affect intellectual performance. The researchers based their hypothesis on a theory that, in achievement situations, red is associ- ated with the risk of failure, such as when teachers use red ink to correct stu- dents' errors. To test their hypothesis, the researchers asked 20 German high Limited View Unlimited View Viewing Condition Figure 5-14 The mean navigation efficiency when navigating in the unlimited and limited viewing condition in Experiment 2. In the limited-view condition, visual information was available as far as the next intersection (further details were obscured by \"fog\"). In the unlimited-view condition, visual information was available to the end of the corridor. Error bars represent 1 standard error of the mean. Source: Stankiewicz, B. J., Legge, G. E., Mansfield, J. S., Schlicht, E. J. (2006). Lost in virtual space: Studies in human and ideal spatial navigation. Journal of Experimental Psychology: Human Perception and Performance, 32, 688-704. Copyright 2006 by the American Psychological Association