The effects of Swedish Knife Model on students’ understanding of the digestive system

Students’ understanding and misconceptions have been the major themes of science education researches over the past five decades. There is a long history of studies examining students' alternative conceptions within biology and there has been now a substantial body of literature documenting the various types of conceptions or misconceptions held by students at different educational levels. The most frequently researched subjects in biology are genetics, cells, diffusion and osmosis, photosynthesis, environment and respiration (e.g. Sanders, 1993; Hazel and Prosser, 1994; Özkan, Tekkaya and Geban, 2004; Saka et al, 2006; Dikmenli, 2010). Other problematic topics within biology are internal organs, organ systems and the processes within our bodies (e.g. Bahar, Johnstone and Hansell, 1999; Cuthbert, 2000; Jaakkola and Slaughter, 2002; Dalkıran, Kesercioğlu and Boyacı, 2005). Toyoma (2000), examined young children’s awareness of biological transformations associated with eating and breathing. He found that young children rarely refer to biological transformation. Furthermore, the results of an international study showed that the most well-known organs generally belong to the digestive system, the gaseous exchange system and the skeletal system. Students had a better knowledge of their internal organs, but a limited understanding of their organ system (Reiss et al., 2002). Teixeira (2000), researched how young children aged 4-10 conceptualized the structure and the function of the digestive system. The results indicated that the younger children explained the function of the organs based on their daily inferences. On the other hand elder children’s knowledge of the digestive system had a biological basis. Garcia-Barros et al. (2011) also examined the younger children’s (aged 4-7) knowledge of digestive and respiratory systems. They also found that the younger children know about their digestive organs before formal instruction at school. But their knowledge about their functions was not adequate.
Cakici (2005) investigated 4th and 5th level (ages 10–11) students’ understanding of digestion. He found that some of the students considered digestion as ‘melting of foods’ rather than ‘breaking foods down’. Some of them also described digestion as a filtering process. They believe that stomach filters food in order to separate the useful and waste parts of the food. These findings of the study revealed that social influences and everyday language had an important effect on children’s learning of the digestive process. Carvalho, Silva and Clement (2007), analyzed the topic of digestion in 63 Portuguese textbooks (1920–2005). Their findings revealed that the explanation of the digestive process in the textbooks is clear, but images and pictures are confusing. And the visual problem of the textbooks is persistent throughout the period studied. Dictatorship had effective in 1926-1974 in Portuguese. To demonstrate the influence of this period, they compared their books with French textbooks (which developed during the same period with the aim of presenting clearer representations of the digestive tract). The findings of the study suggested that confusing and inadequate visuals in textbooks may be important reason of forming misconceptions and weak learning of the digestive function. Güngör and Özgür (2009), examined the effects of the didactic factors on development of 5th grade students’ misconceptions about digestive system. The results of the study revealed that the curriculum, textbooks and teachers were not effective to overcome students’ misconceptions. Students had learning problems about digestive and excretory systems. It was suggested that determination of the students’ misconceptions before instruction and reorganizing the teaching environment based on these misconceptions are necessary for construction of effective learning. Teachers should enrich teaching materials to prevent learning problems rooted from didactic. Curriculums and textbooks also should contain alternative teaching activities to guide teachers.

In the light of the aforementioned studies it can be said that the organs of digestive system, their functions and the mechanism of the digestion are problematic subjects for the students at different education level. Some important causes of these learning problems may be indicated such as drawings and the confusing knowledge in the textbooks, traditional, teacher centered teaching methods, cultural interactions of the students, media and everyday language. The sources of formation of misconceptions are very much and misconceptions are quite resistant to change. It is really difficult to overcome these misconceptions and to provide meaningful learning by only using didactive methods, visuals and questioning. However, there are limited studies which prefer alternative student centered teaching methods in order to prevent the formation of students’ misconceptions and also to replace the nonscientific knowledge of students with scientific ones.

Soyibo and Evans (2002) examined the effects of co-operative learning on the understanding of students, in terms of human nutrition. Rule and Furletti (2004) examined the effects of object box to teach human body system. Some other researches are also present but they only introduce teaching materials for teachers or other educators such as models or educational games. For example, Lock and Richard (1996) developed an educational game to teach structure of animals and plants for primary and second level students. Based on examined literature it can be said that there are very limited empirical studies in this subject area. Therefore it is thought that introduction of alternative teaching materials for teaching digestive system are important to increase the quality of teaching. This paper will provide a contribution to the literature both empirical data and teaching material specific for digestive system. Different student centered teaching activities were used together in this study. We used ‘Swedish Knife Model” term to collect them under a title. Frequently, one method such as concept map, conceptual changing text or analogy etc. is used itself to remedy students’ misconceptions (e.g. Heywood, 2002; Coll, 2005; Keppens and Hay, 2008; Aydin et al, 2009; Akamca and Hamurcu, 2009; Chin and Teou, 2009; Çalik, Okur and Taylor, 2011). These materials are also effective to overcome students’ learning problems but teaching based on one material may be boring for the students and may not provide high motivation and effective learning outcomes (Kurnaz and Çalık, 2008). From this perspective, it was used different teaching activities such as puzzle, analogy, structured grid, completion of the story and cut and stick activities and it was introduced as Swedish Knife Model. This means that anybody may use this model chancing the activities. Is is believed that this model will give opportunity to teachers to select activities according to students’ levels and property of the subject.

Significance of the Study

Digestive system which students have misconceptions is fundamental to biology knowledge because all body systems are interrelated. This means that the learning of this subject will be effective in the meaningful learning of other organ systems (Solomon et al, 1993). Students’ inability to link new information about digestion may also cause misunderstanding of the concepts related to respiration, photosynthesis and energy in food chain (Sanders and Cramer, 1992). Moreover, a sound understanding of this topic may help students to gain a healthy attitude to nutrition and, in the long term, have a healthier life. Parents and the mass media also pay much attention to food and eating; thus, it is very likely that students may develop misconceptions about these concepts through their interaction with the environment in their daily lives.

An awareness of students’ understanding of the subject, in terms of the digestive system, is important in the planning of teaching-learning methods for the classroom. Students' preconceptions or existing misconceptions may be a barrier for the future learning: this has been shown in a number of studies (e.g. Swell, 2002; Tekkaya, 2002). Despite the fact that student' misconceptions in this area are well known to teachers (Yip, 1998), little research has been done to identify the nature and causes of the learning problems and very limited effective instructional strategy has so far been devised to deal with this problem (e.g. Soyibo and Evans, 2002). Moreover, the method of drawing was mostly used to determine the students’ misconception about the digestive organs. Drawing provides information about location, but not other aspects of body organs/organ systems (e.g. Teixeira, 2000; Reiss and Tunnicliffe, 2001; Reiss et al, 2002, Cerrah Ö, 2007). It is necessary to gather written response for examining what students know about the organs and their functions. This study attempts to address this deficiency by exploring students' understanding of the digestion and digestive organs. Hake (1998) indicates that participation of students actively in the learning process generally induces a situation in which knowledge has to be constructed by the students themselves, so that students don’t become spoon-fed. In this study, different activities were used to overcome any learning problems of the students about the digestive system and it was called Swedish Knife Model. There may be some studies comprising application of two or three methods for teaching but terming such an application as Swedish Knife Model is new for literature.

In the present study, activities were designed in a worksheet paper. We thought that the worksheet is very suitable for the combination of several activities. The aims of including these different activities are (a) to make learning more fun for the students and (b) to create repetition and enable the construction of meaningful learning. The sample of the study also increases the importance of the study. Elementary school is a place of basic instruction and, if misconceptions of the students could be minimized at this level, transferring of such misconceptions to higher grades may be prevented.

The Problem of Study

The purpose of this study was to develop a teaching material including different activities called as Swedish Knife Model and to determine its effectiveness on students’ misconceptions of digestive system. For this aim the following research questions were addressed:

What do the students know about the digestive system? Do they have misconceptions about the functions of the digestive organs and the mechanism of digestion?
Does Swedish Knife Model help students to change their misconceptions to more scientific ones?
How do the students assess teaching process provided by Swedish Knife Model?