Preconceptional

The information may not be readily distinguishable either because it is too faint or because it may not be easily separated from other similar information. For example, a critical measurement on a multipoint temperature recorder may be lost in the surroimding clutter of irrelevant information. As discussed in the cognitive engineering approach described in Section 2.6, the worker may also ignore sources of information because of preconceptions that lead him or her to believe they are not significant. 

Having preconceptions - preconceived ideas regarding mentees, their needs and their business obstructs the identifications of their real needs. 

Finally, of paramount importance for the proper interpretation of laboratory observations is the knowledge of the relevant theory. Hodson (1986) maintained that observations are theory-dependent and therefore fallible and biased. Even scientists themselves hold preconceptions and biases about the way the world operates, and these affect their ability to make observations ( theory-laden observations ). According to Johnstone and Al-Shuaili (2001, p. 47) investigation is very knowledge dependent and cannot take place in a knowledge vacuum. As a result, students who lack the requisite theoretical framework will not know where to look, or how to look, in order to make observations appropriate to the task in hand, or how to interpret what they see (p. 44). 

By dealing with historical controversies, students preconceptions can be affected (Jansen et al., 1995). 

One of the intensively discussed topics was the question about the shape of atoms - a question with also high educational relevance, if we think of some students preconceptions. We can focus on two main positions One group of chemists observed that crystals always broke to parts with similar shapes to those of the original crystal. Therefore, their theory was that the smallest particles of atoms must have also the same shape as the macroscopic crystal. If we follow Domenico Guglielmini (1655-1710), the particles of sodium chloride would be cubic, those of calcspar would be triclinic. Hexagonal-prismatic and trigonal-prismatic crystals... 

How can students articulate their preconceptions in the classroom freely Several techniques are known like drawings, mapping techniques and open discussions. Another idea is the use of concept cartoons. In this approach, persons with different opinions (which maybe show similarities to students conceptions) are depicted. The students can use these opinions as a starting point to discuss their own opinions in classroom (Keogh Naylor, 1999). Such cartoons can also be designed by using historical ideas as impulses to initiate students to think about their own conceptual explanations. 

The students discuss these ideas and propose experiments to verily or falsify one of the presented theories. From a methodical point of view, several approaches from discussions, poster presentations up to actual role-plays are possible. The students have the possibility to choose one of the scientists as an advocate for their preconceptions. Using this technique, it will be easier for the students to express and defend their conception in classroom. 

In general, this explorative study cortfirmed the ttsefulness of historical approaches to enhance students discussiorts and reflectiorts about their own ideas. The pairs often came into a dialogue about srritable and rmsrritable theories and tried to find arguments pro or agairrst the one or the other. Typical preconceptions like the brick-like arrangement of atoms were not fotmd. 

Pfundt, H. (1975). Urspriingliche Erklarungen der Schuler fur chemische Vorgange [Students Preconceptions of Chemical Processes]. DerMathematisch-naturwissenschaftliche Unterricht, 28(3), 157-162. 

Monaghan Slotta (2001) notice that despite the amount of literature on the understanding of students preconceptions as well as on the pedagogy for assisting students conceptual change, the majority of middle school and high school science... 

It should be remembered that in the above examples what is nucleophilic attack from the viewpoint of one participant is electrophilic attack from the viewpoint of the other. Any designation of the process as a whole tends therefore to be somewhat arbitrary, reflecting as it does our preconceptions about what constitutes a reagent as opposed to a substrate (cf. p. 30). 

Preconception interventions have been shown to improve pregnancy outcomes. 

The research scientists recognized that they could not fulfill this mission by animal experiments alone. Employees at Edgewood Arsenal volunteered, but research deficiencies, including a lack of controls and the preconceptions of subjects familiar with the agents, limited the value of these studies. 

Hypothesis (4) Inadequate evaluation methods and lack of qualification of commercial users prevent an informed product choice and increase the significance of emotional evaluation elements (e.g. preconception water-based = health and environmentally friendly )... 

Boyle s demand for experimental analysis as the arbiter of elemental status is a central component of this change. Another reason for the revolution was the relinquishment of old preconceptions about what elements should be like. For the classical scholars, an element had to correspond to (or at least be recognizable in) stuff that you found around you. Many of the substances today designated as elements are ones almost all of us... 

They assumed initially that he must have lived during the Bronze Age, around 2000 bc, since the axe blade looked like bronze. But the true age of Oetzi s body was gauged not from such suppositions but from a scientific measurement. The technique of radiocarbon dating showed that he had died much earlier, around 3300 bc. The axe blade turned out to be made from copper, smelting of which predates the invention of bronze. Copper is soft and was thought to be little used for tools. Oetzi s implement challenged that preconception. 

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