Exploring the link between task features and generalisation
Exploring the link between task features and generalisation
复制标题
探索任务特征和泛化之间的联系
DOI:
10.1080/14794800902732233
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发表时间:
2009
影响因子:
1.3
通讯作者:
Chua B
中科院分区:
文献类型:
--
作者:
Chua B
Research on students’ expression of generality in pattern-generalising problems has widely documented their difficulties in articulating and representing the functional rule in words or in algebraic notation (Hoyles and Küchemann 2001). But recent studies seem to attribute the difficulties mainly to the way the patterns are depicted in such problems (Stalo et al. 2006; Lannin, Barker and Townsend 2006). Apart from these findings, little else is known about what and how other features of the problems might affect students’ abilities to express generality. In this study, we speculate that students’ performance in pattern-generalising problems might be influenced by the five task features described below.(i) The format of pattern display. There are two types of pattern-generalising problems: numerical or figural. Numerical generalising problems list the pattern as a sequence of numbers or equations while the figural type uses diagrams to depict the pattern. This task feature is concerned with whether the pattern is listed as a sequence of numbers, equations or diagrammatic figures, or simply as a single diagram.(ii) The type of functions. The pattern in a generalising problem can be represented as a rule showing the relationship between two variables. This task feature considers whether the rule describes a linear or non-linear relationship.(iii) The number of independent variables involved. The rules in most of the pattern-generalising problems reported in the literature are kept simple to linear functions of the form N0an'b, where N denotes the nth term. Such rules contain only one independent variable, n, which is normally the ordinal number indicating the position of the term or the diagram in the pattern. However, some problems involve rules comprising more than one independent variable. A case in point is the pond-tiling task where students are asked to determine the number of unit square tiles needed to surround a rectangular pond of any given dimensions with a layer of tiles. In this task, the number of tiles required depends on two independent variables: the length and width of the pond. We like to emphasise that the simplified form of the rule should be considered when determining both the type of functions and the number of independent variables involved.(iv) The reference to the generator. In some generalising problems, in particular the figural type, the independent variable can be connected to a certain
DOI:
--
发表时间:
2006
期刊:
影响因子:
--
作者:
S. Michael;I. Elia;A. Gagatsis;A. Theoklitou;A. Savva
通讯作者:
A. Savva