Ruth Stavy

The Development of Biological Knowledge: A Multi-National Study.

Abstract This study was designed to differentiate between universal and culturally specific aspects of childrens biological understanding. Kindergartners, second graders, and fourth graders from Israel, Japan, and the United States were asked whether people, other animals, plants, and inanimate objects possessed each of 16 attributes. The attributes included life, unobservable attributes of animals, sensory capacities, and attributes of all living things. The results indicated that children of all three ages in all three countries knew that people, other animals, plants, and inanimate entities were different types of things, with different properties. Children in all cultures were extremely accurate regarding properties of humans, somewhat less accurate regarding properties of other animals and inanimate entities, and least accurate regarding properties of plants. As predicted from cultural analyses, Israeli children were the most likely to fail to attribute to plants qualities that are shared by all living things. Also as predicted, Japanese children were the most likely to attribute to inanimate entities attributes possessed only by living things. In contrast to many previous findings, U.S. children in the study presented here displayed more accurate scientific knowledge than age peers in Japan or Israel. The results were analyzed in terms of how cultural beliefs and linguistic categories affect knowledge acquisition processes and scientific understandings.

How students aged 13‐15 understand photosynthesis

Difficulties in the understanding of photosynthesis by Israeli junior high school students were examined. Thirty‐three students were interviewed and asked about chemical and ecological issues of photosynthesis. Difficulties were found in their understanding of the living body as a chemical substance, lack of knowledge about the chemical elements that compose the living body, and difficulties in understanding that gas (CO2) is the source of the plants body. A major problem was the perception of photosynthesis as a type of respiration. Difficulties were also found in students’ understanding of concepts related to the ecosystem, such as the oxygen cycle in nature and autotrophic feeding as the first step of the food chain. Considering these difficulties, we recommend changing the way of teaching these issues. Such a programme is now being tested.

Intuitive rules in science and mathematics: the case of ‘more of A ‐‐ more of B’

In the last twenty years researchers have studied students’ mathematical and scientific conceptions and reasoning. Most of this research is content‐specific. It has been found that students often hold ideas that are not in line with accepted scientific notions. In our joint work in mathematics and science education it became apparent that many of these alternative conceptions hail from the same intuitive rules. We have so far identified two such rules: ‘The more of A, the more of B’ and, ‘Everything can be divided by two’. The first rule is reflected in students’ responses to many tasks, including all classical Piagetian conservation tasks (conservation of number, area, weight, volume, matter, etc.), in all tasks related to intensive quantities (density, temperature, concentration, etc.), and in tasks related to infinite quantities. The second rule is observed in responses related to successive division of material and geometrical objects, and in successive dilution tasks. In this paper we describe and di...

Children's ideas about ‘solid’ and ‘liquid’

Students usually learn about the states of matter in the upper grades of elementary school. On the basis of this knowledge in physics the particulate theory of matter is introduced in junior high school. The objective of this research was to study the preliminary knowledge students possess regarding the concepts ‘solid’ and ‘liquid’ from kindergarten age (5 year olds) until seventh grade (12 year olds). Our findings show that a child can successfully classify liquids from an early age. This success is due to the idea that ‘all liquids are made of water’. The classification of solids follows a different pattern: Whereas rigid solids are classified correctly by children of all ages, non‐rigid solids are correctly classified by only 50% of children of all ages; the other 50% refer to non‐rigid solids as a separate group. Powders are misclassified by all ages and are referred to either as liquids or as a separate group. Educational implications are discussed.

Pupils’ problems in understanding conservation of matter

This paper describes the acquisition of conservation of matter by students aged 9‐15. Students were tested for their ability to recognize weight conservation as well as reversibility of process in the following changes in matter: translocation, melting, dissolving and evaporation. It was found that children who recognized weight conservation in the translocation task did not necessarily recognize the same in the melting tasks, and those who recognized it in the melting tasks did not necessarily do so in the evaporation tasks. Students believe that a molten material weighs less than the same material in its solid form and that gas weighs less than the same substance in its liquid or solid form. In addition, students who recognized weight conservation were not always aware of the reversibility of the process. Until the age of 12 specific perceptual input from the task dramatically influences students’ responses to the conservation of weight tasks but not to the reversibility of process tasks.

Development of intuitive rules: evaluating the application of the dual-system framework to understanding children's intuitive reasoning.

Theories of adult reasoning propose that reasoning consists of two functionally distinct systems that operate under entirely different mechanisms. This theoretical framework has been used to account for a wide range of phenomena, which now encompasses developmental research on reasoning and problem solving. We begin this review by contrasting three main dual-system theories of adult reasoning (Evans & Over, 1996; Sloman, 1996; Stanovich & West, 2000) with a well-established developmental account that also incorporates a dual-system framework (Brainerd & Reyna, 2001). We use developmental studies of the formation and application of intuitive rules in science and mathematics to evaluate the claims that these theories make. Overall, the evidence reviewed suggests that what is crucial to understanding how children reason is the saliency of the features that are presented within a task. By highlighting the importance of saliency as a way of understanding reasoning, we aim to provide clarity concerning the benefits and limitations of adopting a dual-system framework to account for evidence from developmental studies of intuitive reasoning.

Cognitive conflict and intuitive rules

This paper is a part of an extensive project on the role of intuitive rules in science and mathematics education. First, we described the effects of two intuitive rules ‐‐ ‘Everything comes to an end’ and ‘Everything can be divided’ ‐‐ on seventh to twelfth grade students’ responses to successive division tasks related to mathematical and physical objects. Then, we studied the effect of an intervention, which provided students with two contradictory statements, one in line with students’ intuitive response, the other contradicting it, on their responses to various successive division tasks. It was found that this conflict‐based intervention did not improve students’ ability to differentiate between successive division processes related to mathematical objects and those related to material ones. These results reconfirmed that intuitive rules are stable and resistant to change. Finally, this paper raised the need for additional research related to the relationship between intuitive rules and formal knowledge.

The psychological structure of naive impetus conceptions

Abstract The present paper analyses, on the basis of questionnaires and interviews, the various factors affecting the naive impetus interpretations in tenth and eleventh grade students. It has been found that, according to naive subjects, the action of impetus (even in the absence of any external force) depends on the shape, the weight and function of the moving body. A certain variety of naive impetus interpretations has also been found: the Marchian type‐‐the impetus is self‐expending; the Buridanian type‐‐the impetus is of a permanent nature; the transition to the Newtonian conception.

Intuitive rules in science and mathematics: a reaction time study

It has been observed that students react in similar ways to mathematics and science tasks that differ with regard either to their content area and/or to the type of reasoning required, but share some common, external features. Based on these observations, the Intuitive Rules Theory was proposed. In this present study the framework of this theory was employed and the reaction times of two types of responses were measured: those that are regarded as intuitive and those that are viewed as counter-intuitive. The motivation behind this study was to empirically address the immediacy characteristics of intuitive responses in the context of science and mathematics. The focus was on the comparison of area and perimeter of geometrical shapes, in the context of the intuitive rule more A – more B. The main findings showed that the reaction times of intuitive responses were, indeed, shorter than reaction times of counter-intuitive ones.

Intuitive rules in science and mathematics: the case of ‘Everything can be divided by two’

In the last twenty years, researchers have studied students’ mathematical and scientific conceptions and reasoning. Most of this research is content‐specific. It has been found that students often hold ideas that are not in line with accepted scientific notions. In our joint work in mathematics and science education, it became apparent that many of these alternative conceptions hail from a small number of intuitive rules. We have so far identified two such rules: ‘The more of A, the more of B’, and, ‘Everything can be divided by two’. The first rule is reflected in students’ responses to many tasks, including all classical Piagetian conservation tasks (conservation of number, area, weight, volume, matter, etc.), all tasks related to intensive quantities (density, temperature, concentration, etc.), and tasks related to infinite quantities. The second rule is observed in responses related to successive division of material and geometrical objects, and in seriation tasks. In this paper we describe and discus...