CHILDRENS UNDERSTANDING OF EQUALITY-INEQUALITY RELATIONSHIPS FOR LIQUID QUANTITIES - THE ROLE OF MINIMAL-DIFFERENCE CONCEPT EXAMPLES

When one of two same-amount liquid quantities was actually, or propose d to be, altered by a very tiny (smidgen) amount, kindergartners and 2 nd graders failed to recognize the resulting inequality, whereas 3rd a nd 4th graders were increasingly successful. Alterations larger than a smidgen, but still small, improved the judgments of 2nd, 3rd, and 4th graders but left kindergartners still thinking that equality was unch anged. Alterations in larger amounts that provided noticeable perceptu al discrepancies led to nearly perfect inequality judgments across all grade levels. A rigorous evaluation of children's understanding of eq uality-to-inequality changes must include minimal-amount differences i n a quantity along with the solicitation of verbal reports.