When people are presented with small sets of elements such as dots they can very easily determine their number. This ability has been called subitizing. The present paper reports results from four experiments. The discussion focuses on the question whether one or two psychological processes have to be assumed for this task of subitizing. Taken together our results support the two-process theories. In particular, a distinction between a process of separation and a process of enumeration is suggested. Experiments 3 and 4 support the canonical pattern hypothesis. Canonical patterns are processed substantially faster than noncanonical patterns. Furthermore, if a complex pattern can be broken down into small canonical patterns, then participants follow a partition and add strategy.

R. H. Logie and D. A. Baddeley (1987) suggested that event counting may be supported by a phonologically based working-memory structure referred to as the phonological loop. However, inconsistent results concerning the detrimental effects of irrelevant speech on event counting led them to propose that lexical or semantic representations are also involved. In 4 experiments, the authors showed that this extension of Logie and Baddeley's original conceptualization was unnecessary. Instead, the number of irrelevant syllables spoken per time unit, a factor that was not taken into account in previous research, can explain Logie and Baddeley's results. In addition, the present results support the hypothesis that in cases of interference from the auditory channel, correction processes that help to recover the current running total from past running totals are also involved in counting performance.

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In this study, we investigated whether computer-animated graphics are more effective than static graphics in teaching statistics. Four statistical concepts were presented and explained to students in class. The presentations included graphics either in static or in animated form. The concepts explained were the multiplication of two matrices, the covariance of two random variables, the method of least squares in linear regression, alpha error, beta error, and strength of effect. A comprehension test was immediately administered following the presentation. Test results showed a significant advantage for the animated graphics on retention and understanding of the concepts presented.