Abstracts 2005 - The Psychonomic Society
Abstracts 2005 - The Psychonomic Society
Abstracts 2005 - The Psychonomic Society
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Saturday Noon Posters 4121–4122<br />
specific lesson that requires them to apply a variety of math concepts.<br />
<strong>The</strong>n, after some delay, they are asked to summarize what they have<br />
learned and understood by doing a guided recall task. Lesson plans<br />
and data from five groups of fifth through eighth graders from a region<br />
in the southwestern United States are shown, and methods of<br />
their evaluation, together with conclusions, are presented.<br />
(4121)<br />
<strong>The</strong> Whole or the Sum of the Parts: Strategies for Multidigit Addition.<br />
TINA SHANAHAN & JO-ANNE LEFEVRE, Carleton University<br />
(sponsored by Jo-Anne LeFevre)—Adults and children use a variety<br />
of procedures to solve simple mental arithmetic problems (e.g., 2 + 3,<br />
7 + 9), and these procedures are differentially effective. For example,<br />
in mental addition, direct retrieval of stored number facts is faster and<br />
more accurate than counting up. Strategy choice in simple arithmetic<br />
varies with characteristics of the individual, such as age and math ability,<br />
and with problem characteristics, such as complexity. In the present<br />
research, we examined the range of strategies that were reported<br />
by young adults (N = 30) in mental calculation of multidigit sums (e.g.,<br />
37 + 28) and determined the extent to which these choices were influenced<br />
by individual differences (e.g., math ability) and by problem<br />
characteristics (e.g., complexity, orientation). <strong>The</strong> results have impli-<br />
123<br />
cations for understanding how adults select strategies for complex<br />
mental calculations.<br />
(4122)<br />
<strong>The</strong> Perceptual Constituents of Algebraic Knowledge. DAVID<br />
LANDY & ROBERT L. GOLDSTONE, Indiana University (sponsored<br />
by Robert L. Goldstone)—In addition to being a cognitive activity<br />
of great practical significance, algebraic reasoning is a default<br />
example of symbolic processing. Unlike purely internal processes, algebraic<br />
symbol manipulation requires complicated acts of perception.<br />
This poster presents the results of two experiments that demonstrate<br />
a significant interaction between the application of the order of precedence<br />
laws and nonmathematical grouping effects. In both experiments,<br />
subjects judged whether an equation containing both additions<br />
and multiplications was valid. In the first, the spacing between terms<br />
was manipulated to either support or violate the order of operations.<br />
In the second experiment, the symbols were chosen so that letters on<br />
the sides of an operation were either nearby or distant in the alphabet.<br />
In both experiments, grouping pressures inconsistent with the order<br />
or precedence rule impeded correct judgment only when the correct<br />
answer depended on the grouping. This indicates that algebraic reasoning<br />
interacts with nonmathematical grouping pressures.