Students were asked to read the essay and prepare for a test on it. However, in the pretest condition they were asked questions about the passage before reading it such as “What is total color blindness caused by brain damage called?” Asking these kinds of question before reading the passage obviously focuses students’ attention on the critical concepts. To control this “direction of attention” issue, in the control condition students were either given additional time to study, or the researchers focused their attention on the critical passages in one of several ways: by italicizing the critical section, by bolding the key term that would be tested, or by a combination of strategies. However, in all the experiments they found an advantage in having students first guess the answers. The effect was about the same magnitude, around 10 percent, as in the previous set of experiments.