Piagets theory of cognitive development is divided four into different stages. The concrete operational stage refers children aged 7 to . The word operation concerns the development of strategies and rules for interpreting and investigating the childs world (Oakley, 2004). The word concrete refers to the childs ability to apply these strategies to things that are present (Oakley, 2004). During this stage Piaget discusses conservation, which is the realisation that quantity does not change when nothing has been added or taken away from an object or group of objects, even of there is changes in the form. In this stage the child is able to complete conservation of volume, number, length, weight, liquid, area and mass towards the end of this stage (Oakley, 2004). Piaget also follows the development of inductive logic in each stage, which is a process of using examples and observations to find a conclusion. In this stage the child begins to use their own experience to develop principles or law, which the child applies to the immediate problem (Oakley, 2004). He also discusses class inclusion which is the ability to classify objects into categories. With regards to class inclusion in this stage, the child recognises that categories include smaller sub-groups which are all part of the bigger category (Oakley, 2004). At this stage, the child is not deceived by superficial transformations in the liquids appearance in Piagets conversation tasks and the ability to comprehend that an action can be reversible allows the child to begin to comprehend concepts such as conservation of quantity (Gazzaniga, 208). The child also begins to understand to much more of an extent, how other people view the world, and they feel about things (Gazzaniga, 208). Although it is understood that this development is the beginning of logical thinking, Piaget believed that children at this stage can only reason about concrete things (Gazzaniga, 208). They do not have the capability to reason abstractly, or hypothetically (Gazzaniga, 208). I derived evidence of Piagets theory of the development of knowledge and concepts from interaction with the objects from the study demonstrated by Eysink, Dijksta and
Kuper (200), (Oakley, 2004). Their study involved students solving computer problems (Gazzaniga, 208). Students who struggled were more successful when they were able to draw out pictures of the problem and then solve them (Gazzaniga, 208).
Piagets formal operational stage relates to children of the ages 2 to 6. During this stage, the childs reliance on concrete objects reduces and children have the ability to solve hypothetical problems or imagined problems they are unable to see (Oakley, 2004). This stage is defined by hypothetical deductive reasoning and systematic problem solving (Oakley, 2004). Hypothetical deductive reasoning refers to reasoning that uses detective logic (Oakley, 2004). Whereas systematic problem-solving means that the child has the ability to solve problems in a systematic and logical manner in this stage (Oakley, 2004). As (Oakley, 2004) summarizes, the childs ability to think in an abstract manner occurs at this stage. Gazzaniga (208) understood that this stage involves critical thinking, which is the kind of thinking described by the ability to develop a hypothesis through deductive logic. As explained by Shaffer/Kipp (203), Piaget understood the transition between the concrete operational and the formal operational stages in children. The children in the concrete operational stage are limited as they are only capable of applying their logical thinking to physical or observable objects (Shaffer/Kipp, 203). Whereas children in the formal operational stage progress to be able to demonstrate mental actions on ideas and propositions (Shaffer/Kipp, 203). For evidence to support Piagets theory, Piaget and Inhelder (956) carried out tests to prove this theory. They presented children with the four-beaker problem (Oakley, 2004). The four beakers were filled with odourless and colourless liquid, the children had to work out which combination of liquids turned the liquid yellow (Oakley, 2004). The results showed the children in the concrete operational stage used a random problem-solving technique and the children in the formal operational stage used a systematic approach, these results align with Piagets theory of cognitive development (Oakley, 2004).