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International Journal of Medicine and Pharmaceutical Sciences (IJMPS) ISSN 2250-0049 Vol. 3, Issue 2, Jun 2013, 113-126 © TJPRC Pvt. Ltd.

DETERMINATION OF NORMATIVE VALUES OF THE DEVELOPMENTAL TEST OF VISUAL PERCEPTION (DTVP-2) IN THAI CHILDREN GUNTAYUONG C.1, CHINCHAI S.2, PONGSAKSRI M.3 & VITTAYAKORN S.4 1 2

Ph. D. Student, Biomedical Science, Associated Medical Sciences, Chiang Mai University, Thailand

Assistant Professor, Occupational Therapy Department, Associated Medical Sciences, Chiang Mai University, Thailand

3,4

Associate Professsor, Occupational Therapy Department, Associated Medical Sciences, Chiang Mai University, Thailand

ABSTRACT This study aims to determine the normative values of the Developmental Test of Visual Perception (DTVP-2) in Thai Children. The data was obtained from a sample of 1,120 children, and scoring followed. The DTVP-2 (Thai version) had been examined for validity and reliability. These studies showed that the DTVP-2 (Thai version) has acceptable content validity. The Index of Conjugate (IOC) was established by three reviewers: the IOC is 0.6 in sub-tests 1, 4, 5, 6, and 8;and the IOC is 1 in sub-tests 2, 3, and 7.Byusing a test–retest method, it wasfound that this test has a degree of reliability that is almost perfect. The entire DTVP-2 test has an Intraclass Correlation Coefficiency(ICC) of 0.89, and the ICC sub-tests range from 0.81 - 0.96.1 Results of the normative values of the DTVP-2 (Thai version) showed that 1) there wasa correlation between the age of children and their scores. When the ages of the children are higher, their results on the test are higher scores in every sub-test. 2). In each age range it was shown that the scores for Thai children and in US children who took the original version have similar interval, except in the VMS subtest where Thai children have a tendency to have higher scores in the age ranges from 4 – 5 years old and 8 – 11 years old. The results can be explained from cultural and environmental experiences as per; (1) Thai children enter school atearly age. (2) The curriculum and study hours per day are long period for Thai children and (3) the characters in Thai alphabetsare complicated. All of these factors may encourage writing elements resulting in Thai children developing writing readiness quickly and showing a tendencyto score higher in VMS subtest.

KEYWORDS: Visual Perception, Visual Perception Assessment, Pediatric Occupational Therapy, Developmental Visual Perception Test (DTVP-2)

INTRODUCTION Currently, there is a significant increase in the amount of attention being paid to the study of children as well as to the screening tools that support and encourage these studies 2. Given this increase, finding a reliable test to filter children has been found to be necessary for pre-school and school-age children. Every year, there are many children who face failures in education, e.g. incapability in writing and reading.2 Tools for screening and filtering children are being widely utilized to better understand children’s disabilities and administer treatments in the correct directions. 3 An Occupational Therapist is a specialist who treats children, and is responsible for screening, filtering and treatments. The screenings they perform are related to school children’s success along various modes of perception: recognition, motor, language, intelligence, socialization, daily tasks, writing, and visual perception. 2 This research emphasized visual perception, which is an ability that is directly related to the study of child development. Many studies on occupational therapy for children focus on problems in visual perception and their effects


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on children’s performance in daily living activities, education, work, play, leisure, and socialization.4 Children who have visual perception problems may demonstrate difficulties in such occupational performances. In daily living activities, for example, they could have difficulties with using a spoon and fork during meals or in tying their shoelaces. In terms of school activities, these children may be slow in reading and writing. As for games, these children may demonstrate difficulties in negotiating obstacles while playing with puzzles.5Thestudies found that children with developmental disabilities, such as autism and learning disabilities often have visual perception problems.6-8In addition to identifying specific problems with visual perception, occupational therapists have the role of assessing and treating those which affect the working performance of children. Therefore, it is important for an occupational therapist to use a visual perception test that is able to measure visual perception problems9. For visual perception screening, there are several standardized assessment tools in visual perception and visualmotor performance which are widely used by clinicians and researchers. Burtner et al. (1997) 3 reviewed the visual perception tests that are frequently administered by pediatric therapists. The assessment tools included: Motor-Free Visual Perception Test, Third Edition (MVPT-3)10; Test of Visual-Perceptual Skills (non-motor) (TVPS)11Test of Visual-Motor Skills (TVMS)12Beery-Buktenica Developmental Test of Visual-Motor Integration, Fifth Edition (BEERY VMI)13and The Developmental Test of Visual Perception (DTVP-2).14 This research studied the DTVP-2 because this test has the strengths of being well designed, easy to follow, easy to administer, capable of proving the degree of visual perception problems of each child and of providing separate subscores for each subtest.3It could also help therapists to further analyze children found to have visual perception problems, so that it can be determined which interventions must take place. Besides, the DTVP-2 is one of the tests to be added to the Occupational Therapy Curriculum for the Undergraduate Program at Chiang Mai University. 15 Moreover, the DTVP-2 has been categorized as the test to use for screening children with visual perception problems according to the standards of practice in Thai Occupational Therapy. 16 Therefore, it has the potential to be widely used by Occupational Therapists in Thailand. The DTVP-2 is able to identify children from 4 to 11 years old who are at risk of visual perception problems. There are 8 sub-tests involved: (1) Eye-Hand Coordination, (2) Position in Space, (3) Copying, (4) Figure-Ground, (5) Spatial Relations, (6) Visual Closure, (7) VisualMotor Speed and (8) Form Constancy.14 However, the DTVP-2 was developed in the United States of America, a place with many cultural and environmental differences in comparison with Thailand. Taking the norms from US children for standardization in Thai children might cause errors in screening. In fact, cultural differences in raising children do have an influence on how children perform on the tests17. There are studies of how cultural experiences affect visual perception.6,

18-20

. Schneider

(1995)21said that children from different cultures develop at different rates; therefore applying norms from one culture to another culture could misrepresent the development status of a child. Moreover, the only studies in Thailand have been relative to normative scores of intelligence tests developed by psychologists. 22-30 No studies have been conducted to examine normative scores on visual-perceptual tests for Thai children. Thus, this study aimed to determine the normative data for Thai children. With this research accomplished, Thai Occupational Therapists can have a Thai version of the DTVP-2, based on normative values specific to Thai childrenthat are able to measure their visual perception problems.

METHODOLOGY The aim of this research was to determine the normative values of the DTVP-2 in Thai Children. Approval was


Determination of Normative Values of the Developmental Test of Visual Perception (DTVP-2) in Thai Children

115

secured for the research ethics by the Ethics committee at the Faculty of Associated Medical Sciences, Chiang Mai University. The study was divided into 3 stages: Stage one: Sample Selection The study population was composed of Thai children studying in school under the Office of Basic Education in 2011, between 4 years and 10 years 11 months of age, from a total of 3,619,423 persons. The specific sample group was determined through calculations to find a sample size with precisely 95% reliability and 0.03% error.31Therefore, the sample group was composed of 1,111 children. However, in order to divide the children in each province equally, 1,120 children were given the test. Once the sample group was selected, Multi-stage Random Sampling was utilized with the following processes: 

Cluster sampling by dividing the population by areas, namely the 5 regions of Thailand: the North, the Northeast, the South, Central and Bangkok.

Purposive sampling was conducted in each province from each part of Thailand except Bangkok: Selected provinces included Chiang Mai in the North; NakornRatchasima in the Northeast; Songkla in the South; and Samutprakan in Central Thailand. The purpose being to obtain a sample group from each area that represented the characteristics of the different populations and school sizes. Then simple random sampling was used to select a primary school in each province and in Bangkok by size: small, medium, large, and extra-large.32Each type of school had the following number of students.

Stratified random sampling was used to select the children from each of the 5 provinces, and divided them into 224 students equally through the following methods: o

Survey of the population from each province and each type of school, selected sampling with 15% of the population from small and medium sized schools and 10% of the population from large and extra-large sized schools by using a proportion of the population.33

o

Chosen samples would be utilized after surveying the population. The sample group had to be more specific; 224 students from each region of Thailand, divided into 7 age ranges with 32 students per range.

o

In order to get an accurate sample group from each school, a Sampling Weight Computation was applied at this stage.

o

Selecting classrooms from each school by simple sampling.

o

Selecting children from each classroom by counting them from 1, 3, and 5 (both boys and girls) until the number for the sample group was completed in each school.

Stage Two: Data Collection The researcher collected the data from the sample group, starting with the first process. The following steps were included in the data collection process: 

The researcher presented the research proposal to the Ethics committee at the Faculty of Associated Medical Sciences, Chiang Mai University for review and approval of the research proceedings. The researcher began proceeding once the ethics were approved.

The researcher contacted and asked permission from selected schools by sending letters.


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The researcher selected a sample group from each school that complied with the inclusion criteria and asked permission from parents.

The researcher and two examiners who had been trained in giving the DTVP-2 proceeded to collect the data; the testing process had to be well-organized.

Stage Three: Data Analysis The researcher checked all of the data collected from the test, and proceeded to score the test and analyze the data using SPSS software. The information is presented as follows: 

Descriptive statistics consist of general information of the characteristics of the sample, such as age, gender, handedness, residence and geographical areas.

Test Scores and Interpretation, the DTVP-2 has the following five types of scores.14 o

Raw scores are the total number of points that a child scored for the items of a subtest.

o

Age equivalents (Visual Perception Age) are derived by calculating the average normative group score at each 6 month interval. In the original manual for the DTVP-2, they recommended using standard scores and percentiles rather than age equivalents because of the inadequate statistical properties of the study.

o

Percentiles or percentile ranks represent values that indicate the percentage of the distribution that is equal to or below a particular score.

o

Subtest standard scores provide an indication of the child’s subtest performance. Standard scores allow examiners to make comparisons across subtests. A standard score (or scaled score) is calculated by taking the raw score and transforming it to a standard scale. A standard score is based on a normal distribution with a mean and a standard deviation.

o 

Composite Quotients are derived by the sum of the 8 subtest standard scores and converted to a quotient.

The SPSS program has the following analysis process: o

Computing raw data to find standard scores and percentiles by fixing 6 months as the age interval for 4 – 7 years 11 months, and 1 year as the age interval for 8 – 10 years 11 months.

o

Converting sums of standard scores to Quotients for Compositions.

o

Converting raw scores to age equivalents for subtests.

o

Conducting interpretation of standard scores and composite quotients based on normal distribution.

RESULTS The research has been divided into 3 main areas: 1) Descriptive statistics regarding general information about sample group in terms of age, gender, handedness and geographical area. 2) Developing standardized raw scores and percentiles by specific age ranges of 6 months for ages 4 years – 7 years, 11 months; and 1 year age ranges for ages 8 years – 10 years, 11 months. 3)The translation results of the Thai version of the DTVP-2. Details of each topic are as follows: Descriptive Statistics Results These results include general information on characteristics of the sample in age, gender, handedness, residence


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and geographical area. The sample’s characteristics by age are shown in Table 1 the sample’s characteristics by gender, handedness and residence are shown in Table 2, and the sample’s characteristics by geographical area are shown in Table 3 Table 1: The Sample’s Characteristics in Age Age (Year) 4.00-4.11 5.00-5.11 6.00-6.11 7.00-7.11 8.00-8.11 9.00-9.11 10.00-10.11

Number 160 160 160 160 160 160 160 1120

Minimum (Month) 49 60 69 83 97 109 121 49

Maximum (Month) 59 71 84 96 108 120 132 132

Mean

SD

55.19 66.86 77.56 90.03 102.31 113.54 126.90 88.74

2.55 2.97 3.55 3.72 3.53 3.68 3.39 3.34

Table 2: The Sample’s Characteristics in Gender, Handedness and Residence

Gender Boys n (%) 519 (46.3)

Girls n (%) 601 (53.7)

The Sample’s Characteristics Handedness Left-Handed Right-Handed n (%) n (%) 192 (17.14) 928 (82.86)

Residence Urban Rural n (%) n (%) 867 (77.41) 253 (22.59)

Table 3: The Sample’s Characteristics in Geographical Areas Geographical Areas (Provinces)

Northern (Chiang Mai)

Bangkok

Northeastern (Nakorn Ratchasima)

Southern (Songkhla)

Central (Samutprakarn)

Age

Boys (n) % 19

Girls (n) % 13

Boys (n) % 16

Girls (n) % 16

Boys (n) % 14

Girls (n) % 18

Boys (n) % 17

Girls (n) % 15

Boys (n) % 15

Girls (n) % 17

4.00-4.11

59.4%

40.6%

50.0%

50.0%

43.8%

56.3%

53.1%

46.9%

46.9%

53.1%

15

17

18

14

13

19

19

13

13

19

46.9%

53.1%

56.3%

43.8%

40.6%

59.4%

59.4%

40.6%

40.6%

59.4%

16

16

15

17

9

23

16

16

16

16

50.0%

50.0%

46.9%

53.1%

28.1%

71.9%

50.0%

50.0%

50.0%

50.0%

16

16

12

20

10

22

17

15

17

15

50.0%

50.0%

37.5%

62.5%

31.3%

68.8%

53.1%

46.9%

53.1%

46.9%

14

18

14

18

11

21

13

19

15

17

43.8%

56.3%

43.8%

56.3%

34.4%

34.4%

40.6%

59.4%

46.9%

53.1%

14

18

14

18

11

21

13

19

15

17

43.8%

56.3%

43.8%

56.3%

34.4%

65.6%

40.6%

59.4%

46.9%

53.1%

18

14

19

13

16

16

15

17

14

18

56.3%

43.8%

59.4%

40.6%

50.0%

50.0%

46.9%

53.1%

43.8%

56.3%

112

112

108

116

84

140

110

114

105

119

50.0%

50.0%

48.21%

51.78%

37.5%

62.50%

49.11%

50.89%

46.88%

53.12%

5.00-5.11

160

7.00-7.11

160

8.00-8.11

160

9.00-9.11

160

10.00-10.11

(n)

160 160

6.00-6.11

Total

Total

160

224

224

224

224

224

1,120


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Guntayuong C, Chinchai S, Pongsaksri M & Vittayakorn S

Results of Developing Normative Values These results were taken from the raw data to establish standard scores and percentiles.Before running all of the data,testing for normality by using SPSS software found that the dataset was normally distributed in every age range, except the dataset for the age range of 4-5 years old. However, at this age range a transformation was used which is applied to data that is not normally distributed so that the new, transformed data is normally distributed by taking the log of the data. The standardized raw scores and percentiles of the DTVP-2 in this study show by specific age ranges of 6 months for ages 4 years – 7 years, 11 months; and 1 year age ranges for ages 8 years – 10 years, 11 months. However,this paper shows only the example of Standard Scores and Percentiles for Ages 4.0 through 4-5 as below Table; Table 4: Standard Scores and Percentiles for Ages 4.0 through 4-5

Percentiles

Std. Scores 1

<1

2

EH

1 2 5 9 16 25 37 50 63 75 84 91 95 98 99 >99

0 1-68 69-80 81-97 98-119 120-135 136-143 144-150 151-158 159-164 165-171 172-181

PS

0 1-3 4 5 6 7 8-9 10-11 12-14 15-19 20

CO

FG

0 1-4 5-8 9-10 11-12 13 14-16 17-18 19-21 22-32 33 34-37 39

0-4 5

6-7 8 9 10 11-13 14-15 16-17

SR

0 1-4 5-6 7-8 9-11 12-14 15 16-19 20-25 26-37 38-42 43

VC

0-1 2 3 4-5 6-7 8 9 10 11-16

VMS

0 1 2-4 5-6 7 8-10 11-15 16-18 19-27 28-56

FC

0 1-2 3-4 5-6 7-10 11-13 14-15 16-19

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

The Translation Results of the Thai Version of the DTVP-2 These results converted the Sums of Standard Scores into Quotients for Composites, converting Raw Scores to Age Equivalents for Subtests, and establishing guidelines for interpreting Standard Scores and composite quotients. The conversion of the sums of standard scores to quotients for composites is shown in Table 5, the conversion of the raw scores to age equivalents for subtests is shown in Table 6, the guidelines for interpreting standard scores are shown in Table 7, and the guidelines for interpreting composite quotients are shown in Table 8. Table 5: Converting Sums of Standard Scores to Quotients for Composites Quotient 153 152 151 150 149

Sum of 8 Subtests 130 129 128 127 126

Sum of 4 Subtests 64

Percentile Rank >99 >99 >99 >99 >99

Quotient 101 100 99 98 97

Sum of 8 subtests 80 79

Sum of 4 Subtests

78

39

40

Percentile Rank 53 50 47 45 42


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Determination of Normative Values of the Developmental Test of Visual Perception (DTVP-2) in Thai Children

148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102

125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97-96 95 94 93

63 60-62 59 58 57

56 55 54 53 52 51 50 49 48 47 46

91-92 90 45 88-89 87 86

44

85 84 83

42

43

41 82-81

Table 5: Contd., >99 96 >99 95 >99 94 >99 93 >99 92 >99 91 >99 90 >99 89 >99 88 99 87 99 86 99 85 99 84 99 83 98 82 98 81 98 80 97 79 97 78 96 77 95 76 95 75 94 74 93 73 92 72 92 71 91 70 90 69 89 68 87 67 86 66 84 65 82 64 81 63 79 62 78 61 77 60 75 59 73 58 70 57 68 56 65 55 63 54 61 53 59 52 58 51 55

77 76

38

75 74 73

37

72 71 70

35

69 68 67

33

66 65 64 63 62 61 60 59 58 57 56 55 54 52-53 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35

36

34

32 31 30 29 28 27 26 25 24 23 22 20-21 19 18

39 37 35 32 30 27 25 23 21 19 18 16 15 14 13 12 10 9 8 7 6 5 4 3 3 2 2 1 1 1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1

DISCUSSIONS AND CONCLUSIONS The results for the normative values of the DTVP-2 in Thai children have been divided into two main issues as follows: 

Raw scores from 8 sub-tests of the DTVP-2 found a correlation between children’s age and their scores. This means that when the ages of children are higher, their scores on the test are higher. It explains the Principle of Human Development that has a correlation to two significant issues: maturation and learning, which lead children to develop their abilities according to their age. 34

The ability of visual perception also develops together with other areas as children develop from birth. Visual development will progress according to their maturity and how they learn. Normally, visual perception progresses faster when children are in the age range from 3 – 6 years old until they reach 11 years old.35 Besides, Schneck (2005) also states that visual perception appears from birth and will not be fully developed to maturity until the stage of adolescence.5


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Therefore, visual development is considered to be an individual aspect of development. Maturity, or full development in visual perception depends on visual experiences from the environment and learning done by the children. Likewise, the rate of the development differs from one child to another. Development begins when they are just one-week old. For example, children express their ability to perceive in terms of differentiating between objects which have different figures, and complicated forms.Children are able to differentiate between a circle, triangle and square from an early age. It had been shown that children have the visual discrimination ability to be able to draw a circle when they are 3 years old, a square when they are 4 years old, a triangle when they are 5 years old and a diamond shape when they are 6 years old. These examples demonstrate that the children undergo visual motor integration.35Oncethe children reach the age of development, they develop their perceptual abilities perfectly; e.g., 3 – 5 years old for Figure-ground, 7 – 9 years old for Form Constancy, etc.36 

Raw scores on the sub-tests of the DTVP-2 given to Thai children included scores from the 8 subtests 1.) Eye – Hand Coordination-EH; 2.) Position in Space-PS; 3.) Copying-CO; 4.) Figure – Ground-FG; 5.) Spatial Relations-SR; 6.) Visual Closure- VC; 7.) Visual – Motor Speed- VMS; and 8.) Forms Constancy-FC), and the details show that the score intervals of the test were similar in each dimension for every age range in Thai children and US children in the original version of the DTVP-2.

When considering the details of the DTVP-2, by classifying them into visual motor perception: sub-tests 1, 3, 5, and 7 and non-visual motor perception: sub-tests 2, 4, 6 and 8, the researcher noted that, in this test, both motor related and non-motor related perception are globally standardized. The test includes use of pencils, a response booklet, as well as picture books which characterized the test with straight lines or easily understandable basic shaded objects. Every child has familiarity with horizontal lines, vertical lines, triangles, squares, geometric figures and varieties of dots, etc. These patterns help children to understand easily, and all of the children who completed the test are in school. Since schools are believed to be information centers, the children get used to seeing a variety of pictures similar to those that are used in the test. Moreover, visual perception is one of the global developments that occur according to the Development Policy. Children of every nation and/or race undergo the same developments, even when we consider that some of the developments happen through studying.35 However, when considering factors related to studying, it is seen that Thai children have learning opportunities brought about by globalization which offers media to allhomes; for example, books, television and study materials. Therefore, Thai children have opportunities to perceive a variety of pictures so that they are familiar with the pictures used in the test. Additionally, all sub-tests, except visual motor speed,do not have time restrictions the test.This allows children to complete the test freely and there is with no need to rush. These are the causes of the score intervals on each sub-test, except for visual motor speed, in the age ranges: 4.0 – 4.5 yearsand 4.5 – 4.11 years which show that Thai children have tendency higher scores than US children. In the age range 4.0 – 4.5 years, Thai children have a score interval from 0 – 56, while US children have a score interval from 0 -> 18. In the age range 4.6 – 4.11 years, Thai children have a score interval from 0 -> 55 while US children have a score interval from 0 ->22. In the age ranges from 8.0 – 9.0 years9.0 – 10 years, and 10.0 – 11.0 years, there is an indication that Thai children also have a tendency to score higher than US children. In the age range from 8.0 – 9.0 years, Thai children have a score interval from 0 -> 57 while US children have a score interval from 0 -> 47. In the age range from 9 – 10 years, Thai children havea score interval from 0 -> 55 while US children havea score interval from 0 -> 50. In the age range from 10.0 – 11.0 years, Thai children have a score interval from 0 ->63 while US children have a score interval from0 -> 53.


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A probable to explanation for this is thatthere might be factors influencing Visual – Motor Speed, which lead Thai children to have a tendency to score higher than US children. These factors include cultural and environmental experiences. The first reason is that Thai children enter school at the age of 3. Entering school early provides Thai children with a venue to explore a variety of activities which encourage them to get involved in diverse dimension of writing. Benbow (1995)36gave examples of writing elements and activities in schools which would encourage those elements such as using crayons, painting, scissoring, bead stringing, clay molding, lacing board activities, manuscript and cursive writing, practice of controlled line-drawing, e.g. for vertical drawing: from the top to the bottom or from the bottom to the top, and for horizontal drawing: from the left to the right, training to draw the line from dot to dot, block design, etc. Moreover, Donaghue (1975) and Lamme (1979)37 mentioned that writing readiness in children requires 6 factors which include (1) the development of small muscle; (2) eye – hand coordination; (3) the ability to hold utensils or writing tools; (4) the capacity to form basic strokes smoothly, such as circles and lines; (5) letter perception, including the ability to recognize forms, to notice likeness and differences, to infer the movements necessary for the production of forms, and to give accurate verbal descriptions of what has been seen; and (6) the orientation to printed language which involves the visual analysis of letters and words along with right – left discrimination. Exner (2005)38 said that in kindergarten, children interact through a variety of activities to train their fine motor skills, e.g. use of crayons, scissors, small building materials, puzzles, small cooking, and art projects. In kindergarten and primary school, the main activities children participate in enhance their fine motor skills. In addition, these characteristics are considered in the test of visual- motor speed with the use of pencils to draw in a provided space; the test requires drawing two straight lines in big circles and crossing lines in small squares. In this case, the children need to have some levels of writing readiness, such as, the ability to hold a pencil with correct posture (directions), strength of hand muscles, visual perception control, and eye – hand coordination. The activities provided by the school encourage the use of hand elements in terms of preparing Thai children in writing readiness. These factors might cause Thai children, who enter school early (at the age of 2 or 3), to have a tendency to scores higher on visual- motor speed than US children. The age range from 8.0 – 10.0 years old, which is affected by the second factor could influence the visual- motor speed of Thai children, is consists of children in primary school from grades 2 – 4. Writing ability is very significant for children in this age range. Reeves &Cermak (2002) (cited in Thavornpaiboonbud, 2010) 39 said that children in this age range have the ability to take notes from their teachers, and to submit homework. Additionally, one characteristic of study activities in this age range is setting a time frame to completeaassignment neatly. Graham (1992) and McAvoy (1996) (cited in Amundson, 2005)37, said that children who have delayed writing abilities will take a long time for assignments, and will be show at taking notes in the classroom. Their writing speed will be slow when they receive more writing assignments or complicated assignments.38It is believed that Thai children receive very strong training in writing. This is correlated to the study by McHale &Cemak (1992)40 who examined the amount of time allocated to fine motor activities and the type of fine motor activities that school-age children were expected to perform in the classroom. This study showed that 31% – 60% of activities in school each day are allocated for fine motor activities and 85% are paper and pencil tasks, which are the characteristics of the curriculum and instruction at an elementary level. Thai children are taught 8 subjects: (1) Thai language, (2) Mathematics, (3)Science, (4) Social Equity, (5) Religions and Health Cultures, (6) Physical Educations, (7) Arts of Professionals, and (8) Foreign Languages and Technology. This causes Thai children in primary school to have a long daily hour, from 8.30 – 16.00 hours.32Therefore, it is apparent that Thai children have a long number of hours spent studying and that implies that they will spend more time on writing activities.


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Guntayuong C, Chinchai S, Pongsaksri M & Vittayakorn S

The third factor is the nature of Thai characters. It is evident that the Thai alphabet is different from the English alphabet. The Thai alphabet is composed of 44 letters, 21 vowels and 4 tonal marks while the English alphabet has 26 letters. There are more writing difficulties encountered in the Thai alphabet than the English alphabet. More letters are needed in writing to form words, and the Thai language restricts the position of vowels to specific location. A vowel can only be located on the top of the correct letter. Results from cross–culturestudiesmentioned that the complexity of Chinese letters, which consist of more letters than the English alphabet accelerates the development of visual motor perception, resulting in Chinese children demonstrating higher performance on the test than the American children41. Therefore, it is possible that although Thai letters have are more complicated, with repeated training in writing over long period, Thai children acquired writing abilities. They are able to control their writing direction more quickly and effectively. Thus, on the visual- motor speed test which requires speed to draw the line in the provided spaces;Thai children have a tendency to score higher on the visual motor- speed sub-test. However, this research has found differentiation in presenting age equivalences. That is to say, the results of this study only presented the age equivalence scores on a 6 months basis not on a monthly basis as shown in US data. This is due to an inadequate number of the sample whocontributed monthly ages. Therefore, the calculations of age equivalence on a monthly basis were inapplicable.

CONCLUSIONS The results of this study may be summarized as follows: The normative values of this study showed that as children older, their test scores increase in every sub-test and in each score interval of the sub-test. However, there is one point that was detected from the study: Thai children have a tendency to score higher on the visual motor- speed sub-test than US children from the age ranges 4 – 5 years old and 8 – 11 years old. The results can be classified into the following explanations based on cultural and environmental experiences are classified into the following explanations:(1) Thai children enter school at early age.(2) The curriculum and study hours per day are long period for Thai children and (3) the characters in Thai alphabets are complicated. All of these factors may encourage writing elements resulting in Thai children developing writing readiness quickly and showing a tendency to score higher in VMS subtest.

LIMITATION The limitations of the study are the distribution of the samples. The data collected from the sample groups have no calculation of age equivalence on a monthly basis, which is different from the presentation of US children’s age equivalence which shows scores on a monthly basis. This study only presents age equivalence on a 6 month basis.

RECOMMENDATIONS For future research, these are some recommendations:This study was unable to calculate age equivalence on a monthly basis, which is different from original version of the DTVP-2which is presented by month, due to the limitation of sample groups in some months. Therefore, it is recommended for the next study to control bias, especially selection of samples groups to organize a plan in collecting and distributing data by the age ranges of the sample groups for each month.

ACKNOWLEDGEMENTS The authors give their heartfelt gratitude to the children and teachers who participate in this study.We are also


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thankful to the Faculty of Associated Medical Sciences, Chiang Mai University for providing a grant during this study.

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