An investigation on mental representations on coagulation and melting phenomena of preschool pupils with learning disabilities and typical development

The aim of the present study is to investigate the mental representations regarding the coagulation and melting phenomena of preschool pupils with learning disabilities. In addition, to compare them with the corresponding representations of typically developing children. By so doing, it aspires to shed light to the feasibility of implementing inclusion into teaching science. To fulfil this purpose, an experimental investigation was conducted with 25 pupils with learning difficulties (M=72.50 months, s.d.=8.11) and 25 pupils with typical development (M=72.50 months, s.d.=9.50). Pupils were selected with convenience sampling while interviews were recorded and transcribed. According to data analysis, pupils’ responses were classified into three distinct levels: sufficient, intermediate and insufficient in terms of school knowledge. Drawing from constructivism theory a digital tool called M.R.H.E.T (Mental Representations Heat Exploration Tool) was developed to fulfill research’s goal. A part of this tool is used for the present study. Findings suggest that preschools pupils with learning difficulties use almost the same ideas on thermal phenomena with those used by preschool pupils with typical development, on a different frequency though. This inevitably reinforces the academic belief of inclusive education for pupils with learning disabilities in teaching science.


Introduction
The last decades education research for introducing children aged 4-8 to Natural Sciences has led to the development of an area called Early Childhood Science Education consisting of 4 different approaches namely the "empiricist", the "Piagetian", the "socio-cognitive" and the "socio-cultural approach" [1].Nowadays, a new prominent trend seems to emerge known as Early Childhood Special Science Education.Within this trend, the 4 different approaches mentioned above are examined in the light of special education [2].That is, it tries to extend the research of mental representation about natural phenomena that hold a key role into socio-cognitive approach [3][4][5][6] into pupil that lie into special needs spectrum [7][8][9][10].Moving along this line, this study aims to explore mental representations on melting and coagulation of preschool pupils with learning disabilities and contrast them with those of typical development.

Thermal phenomena: The scientific point of view
Temperature is the property of a body that indicates how hot or cold the body is, relative to a standard body of constant temperature.Τhe higher the temperature of a body, the hotter it is.When a body with a specific temperature comes in contact with another body, energy starts flowing from the body with the higher to the body with the lower temperature.This energy is called heat and will stop flowing as soon as the two bodies acquire the same temperature [11].Therefore, heat will propagate from a hot soup to a metal spoon inside it until the soup and spoon reach the same temperature.
Key role in thermal phenomena is played by the change of state of materials namely melting, coagulation and evaporation.In particular, melting is the transition of a material from the solid to the liquid state while coagulation is the transition of a material from the liquid to the solid state [11,12].Evaporation is defined as the phenomenon where the transition of a material from the liquid to the gaseous state takes place [11,12].This gas can be produced either exclusively from the surface of the liquid (evaporation) or from both the interior and the surface of the liquid simultaneously (vaporization).
Mental representations of pupils on melting and coagulation have been extensively studied in the international literature.These representations are presented below.

Pupils' mental representations on melting and coagulation
Young children seem to respond successfully only to those change of state phenomena that are related to their everyday life experiences while face difficulties to expand this knowledge to other conditions and materials [12,13].So, for example while their everyday experience helps them to effectively describe the phenomenon of melting in familiar environmental conditions, they are unable to relate ice melting to heat supply [12].They characteristically report that an ice cube could break or turn black in case it is overheated.Consequently, difficulty is found in linking the melting phenomenon to heat supply, as children form a type of reasoning, which however does not allow generalizations about melting.
The literature review on pupil's difficulties in change of state highlights the significant barriers they face.The transition of a material from one state to another is attributed to the nature of materials, perceived under specific conditions and explained only on the basis of children's experiences, while basic properties of the phenomenon are ignored [12].Indicative barriers for preschool children include difficulty in predicting the heating process of a quantity of water, in understanding the conservation of liquid, and in recognizing the identity of both liquid and gas that is produced by a heated liquid [14,15].Regarding the phenomenon of evaporation, Ravanis [16] states that preschool children often believe that boiling water for a long time causes it to swell and eventually burst.He also points out that while pupils grasps the idea that steam comes from boiling water, they cannot accept that steam can turn back into water.Kaliampos and Ravanis' [13] research also found that mental representations of children aged 5-6 are influenced by their everyday experiences of their home.As they state, this should be considered as the basis for developing learning situations that lead to precursor model regarding heat.
The empirical research of Kambouri-Danos et al [12] showed that the teaching intervention on preschool pupils positively influenced their thinking about the change of water state as they were able to form a stable precursor model to support their understanding of the phenomenon.Specifically, the preschool children appeared to predict that the water would boil, and that steam would be created, without mentioning the change in water state though.Quite interestingly, preschool children's responses were not linked to the heat or evaporation of water.Instead, it were linked to the phenomenon of coagulation without mentioning everyday thermal phenomena though.
Young children seem to respond successfully only to those change of state phenomena that are related to their everyday life experiences while face difficulties to expand this knowledge to other conditions and materials [13].So, for example while their everyday experience helps them to effectively describe the phenomenon of melting in familiar environmental conditions, they are unable to relate ice melting to heat supply [12].They characteristically report that an ice cube could break or turn black in case it is overheated.Consequently, difficulty is found in linking the melting phenomenon to heat supply, as children form a type of reasoning, which however does not allow generalizations about melting.

Learning difficulties
Learning Difficulties is a contemporary issue that fit into special education context.It is one of the most common categories of special educational needs, as according to international literature, almost half of the students attending special schools have been diagnosed with Learning Difficulties [17].In many cases it coexists with Attention Deficit Hyperactivity Disorder (ADHD) [18].The term mainly refers to difficulties in literacy and acquiring knowledge skills.
Each individual may present different difficulties and characteristics, contributing to the impossibility of compiling a central profile [17].However, there are some common characteristics that constitute Learning Difficulties as a permanent condition which is likely to follow the child throughout his or her life and as an adult.In particular, students with learning disabilities present difficulties in reading and/or writing, memory and following instructions [19].They also have problems with mathematical skills and attention retention.They lack sufficient coordination, organization and have difficulties with time-related concepts [20].Finally, they often document weaknesses in the areas of perception, self-regulation, behavioral motivation, social skills, and emotional development [17].
According to the literature, there are numerous diverse definitions regarding Learning Difficulties.However, the majority of them apply three basic criteria/conditions in order to describe a child with these difficulties.These are the intra-individual discrepancy criterion, the exclusion criterion and the special education provision criterion [18].In particular, the first criterion, intra-individual discrepancy, refers to the existence of a serious discrepancy or disharmony between the child's potential and actual performance in school.It is the main diagnostic criterion demonstrating that pupil's difficulties are real, systematic and persistent and not just some mild or occasional difficulties that the child may experience in his or her schooling.In the second criterion, exclusion, care is taken to ensure that the difficulties are not attributed to deficits relating to sensory difficulties (blindness, deafness), mental retardation, emotional disturbances or even lack of educational opportunities (long-term absence from school).The third criterion for special education is the need to provide assistance and support to pupils with specific learning difficulties.Designing an individualized and tailored teaching intervention to the needs of the pupil is the best strategy to support and enhance their school performance in specific subjects [18].

Inclusion
One of the most prominent movements which seems to dominate special needs field the last decades is that of inclusion.As Dare et al [21] point out, the term inclusion refers both to teaching and learning practices that are designed to include all children to the mainstream curriculum, taking into account their abilities and disabilities as well as to the philosophy that promotes involvement, acceptance, cooperation and feeling of belonging of all pupils.According to the concept of inclusion, children participate in the learning process on an equal basis while their difficulties are analyzed from a different perspective where key role plays the development of innovative teaching strategies [22].
While specific difficulties in implementing inclusion in practice often occur, encouraging the perception of inclusion is undoubtedly a challenging innovation in mainstream classes [23].Indeed, the effective schools are those who adopt inclusive practices, which the learning, teaching, achievements and personal attitudes are taken into account for each children and involve all of them in schooling [24] and not just being present in the same classroom.

Research questions
The present study acts as experimental research in the field of education.It is qualitatively in nature as it tries to shed light into alternative conceptions of two study groups; these are subjects with and without learning difficulties.In order to do so, it uses semi-structured interviews that are based on a digital tool called M.R.H.E.T. (Mental Representations Heat Exploration Tool).This tool, consisted of direct, openended questions that formed the basis and guided the course of the interview process.A convenience sampling technique was implemented in the research to form the two study groups and give answer to the following research questions 1.What are the mental representations on melting and coagulation of pupils with learning difficulties?2. How are these mental representations compared to those of pupils with typical development?

Participants
Two groups of pupils aged 4 to 7 years old constituted the sample of the survey.The subjects attended kindergartens (infant-preschool) and Primary Schools (first grade) located in a semi-rural area of patras (Greece).In particular, Group As the research was carried out during Covid-19 period, interviews were conducted entirely at distance, through WebEx platform.All parties involved (children, parents, researcher) logged in the platform on a pre-scheduled arranged date and time, while in the computer screen the Mental Representations Heat Exploration Tool (M.R.H.E.T.) was depicted.Each interview lasted about 20 minutes where pupils where prompt to elaborate their ideas on the different tasks of M.R.H.E.T. Parents were informed that the interview was being taped and gave their written consent for their child participation on this process.

Instrument
For the purposes of the research project on exploring mental representations of students with learning disabilities in thermal phenomena a computerized tool was developed.M.R.H.E.T. (Mental Representations Heat Exploration Tool) comprises 9 tasks divided into 3 basic sections.For the current study, the third section (C) was used consisting of 3 tasks dealing with melting and coagulation.Particularly, task C1 depicts a tray with an ice cube on it.Pupils are asked what will happen on ice cube if we let it there for a long time.Shortly after, the same tray with the ice cube is portrayed in a gas of fire and the students are asked to express their thoughts about the ice cube if it gets heated for a while (Figure 1).Task C2 depicts a pan of boiling water.As pupils clearly notice that the water level decreases, they are asked where this amount of water has gone (Figure 2) Finally, task C3 depicts a glass of water being inserted into a freezer.Pupils are asked what will happen in the water if we freeze it for a while (Figure 3).

Figure 3. M.R.H.E.T., task C3
The M.R.H.E.T. have been composes from different tasks that appear in the early childhood education literature [13,25].In the current study, the tasks were given to children in digital form, as based on the relevant literature digital environments enable effective learning for children with learning disabilities [9,38] as well as for young children of typical development in STEM subjects [26].These tasks were created to be linked to images from children's everyday life while at the same time promoting visual learning which is considered particularly effective for children with learning difficulties [27].

Data analysis
The research was carried out with interviews (based on the M.R.H.E.T. tasks) which were recorded and transcribed.The children's mental representations were classified into categories based on their distance from school knowledge, according to the relevant literature [13,25].The mental representations emerged from their answers were classified into three levels: sufficient, intermediate and insufficient in terms of school knowledge of a qualitative nature.In the category of 'sufficient' answers were classified those which are compatible with school scientific knowledge.Answers in which the children's reasoning had deficiencies or contradictions were characterized as 'intermediate'.Finally, answers that had nothing to do with school scientific knowledge were classified as 'insufficient'.The analysis and classification of the responses collected during the interviews was done by two independent researchers which had a rate of agreement of more than 95%.As the whole interview process was recorded, the researchers rely on the written transcripts to analyze the data according to the categorization of pupils' responses portrayed above.

Results
In what follows, the rates of pupils' responses for each task of M.R.H.E.T. are presented.Table 1 presents the sum of the results in all three tasks for both groups of students.

The answers to Task C1
84% of pupils with learning difficulties gave a scientifically correct response on task C1.Pupils here stated that the ice cube will melt as it passes from the solid to the liquid state.To quote a child 'The ice cube will melt because the ice cube must be frozen so as not to melt, if we take it out of the freezer it will melt because outside the freezer it is not cold...It will melt faster because it is in the fire and the fire makes the ice cube melt faster' (LD.16).Almost 16% of pupils with learning difficulties answered poorly or did not give any answer to this question.That is, the children did not predict that the ice cube will melt.Typical answers were: 'If you put the ice cube in the fire it will break...it become pieces' (LD.2) and 'If it remains outside, the ice cube will warm up...the ice cube will be hot and not cold' (LD.10).
On the other hand, all pupils with typical development responded adequately to this task.Typical answers here were the followings: 'The ice cube will melt, because it must be frozen so as not to melt, if we take it out of the freezer it will melt because outside the freezer it is not cold...The ice cube will melt faster because it is in the fire and the fire makes the ice cube melt faster' (TD.6) and 'The ice cube will melt because it is from water and melts from the heat... fire will make it melt' (TD.8).
Specific alternative ideas were apparent on pupil's responses that were characterized either as intermediate or insufficient on task C1.Particularly, the first mental representation is that preschool children predict that the ice cube will be broken if you put it on the fire and derives from their everyday experience [15].This idea corresponds to 8% of the sample responses and is apparent in the following pupil's responses: 'If you put the ice cube in the fire it will break...it becomes pieces' (LD.2) and 'the ice cube will get very hot, and it will break...It will become pieces of ice' (LD.19).
Another mental representation is that preschool children at a rate of 8% cannot associate the phenomenon of melting with the supply of heat [14].These pupils believe that the ice cube will warm up and be no longer cold as soon as you put it on fire.Typical answers here were: 'The ice cube will warm up … it will be not hot … it will be cold' (LD.10) and 'The ice cube will become hot...when it is in the fridge it is frozen and when it is outside it becomes hot...when you put it on fire it will burn, it will be hot' (LD.22).

The answers to Task C2
52% of pupils with learning difficulties gave a scientifically accepted response to task C2 stating that the water will evaporate.To quote a child 'The water when it boils, becomes hot...the water disappears with the smoke, I am sure that this is the case' (LD.5).
Almost 20% of pupils with learning difficulties gave an intermediate answer.Here while the children stated that the water will boil and that the steam will form, they did not report any change in water state.Typical answers were: 'The water gets hot, it draws out steam and it becomes hot' (LD.1) and 'the boiling water is hot and makes vapors...'(LD.12).
Finally, 28% of pupils with learning difficulties responded poorly or did not give any answer to this question.That is, children's responses were not associated with warming up or evaporating water.Typical are the following responses: 'The water will fall down...it opened the door and left'' (LD.6) and 'It will boil and becomes milk...' (LD.15).
On the other hand, the majority (56%) of pupils with typical development responded adequately to this task.Quite interestingly, almost 24% of them gave an intermediate response such as 'The water will get too hot...it evaporates, that is, it leaves in the air' (TD.21).Finally, 20% of pupils gave an inadequate answer: 'The water makes bubbles, smokes and gets hot... the water sticks to the pan, the water cannot leave otherwise unless there is a hole' (TD.23).
Specific alternative ideas were apparent on pupil's responses that were characterized either as intermediate or insufficient on task C2.Specifically, a rate of 16% pupils recognize that boiling the water for a long time, leads it to swell and burst [21].This is well reflected in the following responses: 'The water burst and so it left...when it warms up, the water inflates and becomes a big bubble and in the end it bursts" (LD.9) and "The water swelled and burst...that's why we do not see it now" (LD.23).The second mental representation that emerged (12%) was that the responses of preschool pupils who stated that the water will be poured from the pan, without associated it with warming up or evaporating phenomena [14].To quote two indicatively answers 'The water will fall down...it opened the door and left' (LD.6) and 'The water opened the door and left the pan and went to the river' (LD.24).Finally, the mental representation that emerged at a rate of 12% was that as soon as the water get boiled for a long time it burns and therefore leave.Indicative response is the following: 'The water burned and went away' (LD.17).

The answers to Task C3
64% of pupils with learning difficulties gave a scientifically accepted answer to task C3.Specifically, children's predictions were associated with the phenomenon of coagulation which recognized it as a thermal phenomenon.A typical example was the following: 'It will become ice because in the freezer it is very cold and the water freezes' (LD.3).
In contrast, 36% of pupils with learning difficulties gave an 'intermediate' response.While children stated that the water would freeze, they did not mention it as a thermal phenomenon.Typical answers were: 'It will become freeze... it will become ice' (LD.2) and 'it will freeze… we put it like water, and we get it out sometime like ice' (LD.13).
On the other hand, typically developing pupils responded adequately to this task at a rate of 48%.A fairly high percentage of pupils (52%) gave an intermediate answer such as 'It will freeze because it is cold' (TD.9).
Specific alternative ideas such as the water that gets into freezer becomes slush (26%) or even ice cream (10%) were apparent on pupil's responses that were characterized either as intermediate or insufficient on task C3.While the pupils here mentioned that the water will become cold, they referred to the conversion of water into another substance familiar to them from their everyday experience.Indicatives are the following responses 'The water becomes cold in the freezer…becomes slush' (LD.22), 'it will freeze… we put it like water and we get it out sometime like ice…I think an orange juice slush or strawberry slush' (LD.7) and 'The water becomes ice cream in the freezer' (LD.19).

Discussion
Preschool pupil's mental representations, with and without learning difficulties, on melting and coagulation were investigated in the current study.Remarkably, pupils of both groups dealt with the tasks in almost parallel ways.In particular, in task C1 the vast majority of them managed to give responses compatible with school scientific knowledge.Interesting alternative ideas that emerged here was that the heated ice will break or that it will stop being cold any longer.In task C2, almost half of students of both groups dealt with it in a successful manner.The mental representations that were traced here, at almost similar proportions among two groups, were that the water level of the boiling water in the pan will decrease either because it will swell and burst, or because it will fall down, or it will burn.Finally, in task C3 almost half of typical development and 2/3 of pupils with learning difficulties gave a scientifically accepted response.Mental representations that were detected here supported the idea that the water that gets into freezer converts to other familiar substances such as slush or ice cream.
Judging from the above, it can be concluded that pupils aged 4-7 years, irrespectively of their classification as learning disabled or typically developing students, face parallel difficulties and have almost similar mental representations in conceptualizing thermal phenomena of melting and coagulation.This assumption give rise and reinforces the concept of inclusion regardless of the specific talents or difficulties of pupils [28].That is, students with special needs and particularly those with learning difficulties, can be taught thermal phenomena of melting and coagulation in mainstream classrooms and succeed in learning those phenomena as soon as appropriate teaching strategies been implemented in the teaching process.Our finding supports the literature that advocates the positive impact of inclusion in teaching and learning science to students that lie in the special needs spectrum [29,30].
On the context of inclusion different approaches and didactic interventions, that have been used in general classes, could be implemented for teaching the phenomena of meting, coagulation and evaporation.An exemplar paradigm is the embodied activities pointed out by Karlsson [31] that were successfully used to activate preschool pupils' bodies in a way that helped them to conceptualize the notion of evaporation.In addition, the drama activities stated by Akerblom et al. [32] that were employed to teach the state of water and its molecular nature to pupils aged 6 years old.Finally, the dramatic activities about thermal insulation pointed out by Fragkiadaki et al. [33] and Jelinek [34] that clearly highlighted the contribution of the social, cultural, and material environment in the development of the scientific thinking of children.

Study Limitations
Our small sampling consisting of pupils recruited from only two specific Greek regions undoubtedly acts as an important limitation of the study.Certainly, a larger sample could confirm or reverse these findings.Another crucial limitation of the study is the usage of WebEx instead of face to face interviews due to Covid-19 pandemic restrictions.Hence, there is a great possibility that pupils were not able to fully express themselves since they were located at different places from the researchers who conducted the interviews.