NOMAD 10(1), 2005. The role of decision making and resources in group solutions of a problem involving Bayes' formula

 

GLORIA STILLMAN

Abstract
This study was concerned with the decision making behaviour of students at the upper secondary level of schooling. Transcripts of verbal reports produced by student pairs solving a probability problem involving Bayes' Formula were analysed using Schoenfeld's protocol parsing scheme. The students' monitoring and decision making were significant contributors to how solutions evolved but so too were particular words in the problem statement. Both the quality of control behaviour and students' resources contributed to the success or otherwise of their solution. Resource-related factors included misinterpretation of the problem, misreading of the problem, failure to make the connections between probability rules and their conditions of use, and confusion between compound and conditional probability.

Sammanfattning
Denna studie behandlar beslutfattande hos elever på gymnasial nivå. Transkript från inspelningar där elever i par löser sannolikhetsproblem, som innefattar Bayes formel, har analyserats med hjälp av Schoenfelds protocol parsing scheme. Elevernas kontroll och beslutsfattande bidrog på ett signifikant sätt till hur lösningarna växte fram och det gjorde även specifika ord i problemformuleringen. Både kvaliteten på kontrollbeteendet och elevernas resurser bidrog till framgången eller misslyckandet med lösningen. De resursrelaterade faktorerna innefattade misstolkning av problemet, felläsning av problemet, misslyckande med att koppla ihop sannolikhetslagar och deras förutsättningar vid användningen, samt sammanblandning av sammansatt och betingad sannolikhet.

GLORIA STILLMAN
Gloria Stillman is a lecturer in mathematics education at the University of Melbourne, Victoria, Australia. Research interests include teaching and assessing higher-order thinking through contextualised mathematical applications and modelling tasks in a technology rich teaching and learning environment at the secondary school level.