During isolated-word reading, within-word eye-movement tactics (i.e. whether the eye makes one or more fixations on the word) depend strongly on the eye's first fixation position in the word; there exists an optimal landing position where the probability of having to refixate the word is much smaller than when the eye first fixates other parts of the word, The present experiment was designed to test whether the optimal landing position effect still exists during text reading, and to compare the nature and strength of the effect with the effect found for isolated words. The results confirmed the existence of an optimal landing position in both reading conditions, but the effect for words in texts was weaker than it was for isolated words, probably because of the presence offactors such as reading rhythm and linguistic context. However, the effect still existed in text reading; within-word tactics during text reading are dependent on the eye's initiallanding position in words, Moreover, individual fixation durations were dependent on withinword tactics, Thus, the initial landing position in words must be taken into account if one wishes to understand eye-movement behavior during text reading. Further results concerned the effects of word length and word frequency in both reading conditions,
583A large number of experiments in recent years have been done to investigate the factors that determine fixation positions and fixation durations in reading, As concerns fixation positions, the preferred landing position in words is generally located at the middle or at the beginning of words (Dunn-Rankin, 1978;McConkie, Kerr, Reddix, & Zola, 1988;Rayner, 1979), but it depends on several factors. McConkie et al. (1988), in a very detailed study, and O' Regan (1979) have shown how landing positions in words depend on the length of the word the eye is leaving, the length of the word the eye is saccading towards, and the position relative to a word from which the eye's movement is launched. Although many experimenters have studied the influence of linguistic factors on the probability of fixating a word during reading (e.g., Balota, Pollatsek, & Rayner, 1985; Ehrlich & Rayner, 1981;Zola, 1984), there is only weak evidence that linguistic factors determine where the eye lands next (for a review of this question, see O'Regan, 1990).