Can students read secondary science textbooks comfortably? Bob Chui Seng Yong, Sultan Hassanal Bolkiah Institute of Education

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Brunei Int.J.of Sci.& Math. Edu., 2010, Vol 2(1), 59-67 ISSN 2076-0868


Bob Chui Seng Yong, Sultan Hassanal Bolkiah Institute of Education, Universiti Brunei Darussalam, Brunei Darussalam, <>

A common observation in a science class is when teacher says to the students, “Please take out your science textbook, turn to page 178 and read the chapter on Photosynthesis silently for 5 minutes.” One wonders how many students can actually read and understand the texts as they glance through those pages. Does the readability of the texts match with the reading ability of the students? The purpose of this study attempts to answer the above question. In this study, the readability of ‘Secondary Science for Brunei Darussalam Book 1’ (CDD, 2008) was measured using the Gunning, Fry and Flesch-Kincaid methods. The reading level of a sample of Grade 7 students was measured using the cloze test. Results showed that the readability of science textbook far exceeds the reading age of the students. In terms of the reading level, only about a third of the students were found to be reading at the instructional level while the majority were found to be at the frustration level. Moreover, results also showed that there was a positive significant association between student reading level and achievement in science.

The potential of improving the quality of science education is imminent if teachers take more serious attention to the importance of language in the learning of science. Wellington and Osborne (2001) claimed that “Language is the major barrier (if not the major barrier) to most pupils in learning science” (p. 2). They reasoned that science has its own language and learning the language of science poses a major challenge to pupils. Rutherford (1993) made an important distinction by elaborating that the language of science is a language that transcends other language differences. Rutherford further explained that it would be much easier for a scientist to communicate with another scientist than to a non-scientist who speaks a common language. The difference between everyday language and science terminology was also pointed out by Garraway (1994) in which he argued strongly that students, irrespective of first or second language speakers, are learning a new language when learning science.

As the number of students learning science through English as a second language (ESL) has increased in recent years (Rosenthal, 1996), the use of English as a medium of instruction and its influence on learning science has become an important issue. Studies had found that ESL learners encounter numerous problems because learning science through English is complicated by having to simultaneously master both the science content and language at the same time (Rollnick, 1999). Lemke (1997) reported that ELS learners have to immerse in two social practices together at the same time when learning science: one which has to do with learning a new language (i.e. English) and the other which has to do with learning science (i.e. language of science).

One of the major problems confronted by ESL learners in learning science is the lack of language proficiency. As reported by Duran, Dugan and Weffer (1998) language minority students in high schools did not have the necessary linguistic tools to construct advanced science concepts. As a consequence they have weak scientific knowledge because of their inability to construct scientific concepts and meanings effectively due to their low-level English skills. In a separate study on high achieving mathematics students of immigrants, Duran and Weffer (1992) observed that limited English proficiency of this group of students affected their achievement test scores in science. Santa and Alverman, (1991) explained that students whose home language is not English are not only challenged by the expectations of high school coursework in science but also by the language experience of having to read science textbooks and derive meanings from analogy and metaphor that are frequently used in science. Studies carried out by Ramorogo and Wood-Robinson (1995) on Botswana children suggested that learning science in a second language poses a severe barrier to comprehension of the text being read. They found that learning the new language itself poses a severe problem to many of the students and, not least, when they have to learn new concepts in the language in which they are not very proficient. Another problem faced by ESL students is their inability to understand teacher discourse during instruction and this explains why Mexican American students lag behind the achievement levels of their English-speaking counterparts (Buriel & Cardoza, 1988; Nielsen & Fernandez, 1981).

The second major problem is related to the language used in science textbooks. Studies have shown that the language used in some science textbooks exceeds the normal experience of many elementary school students (Merzyn, 1987) and high school students (Lynch, et al., 1972 cited in Letsoalo, 1996, p. 184) for whom they are written. As Curtis and Millar (1988) have argued that if the understanding of textbook language is difficult for English speakers it is likely to be even more difficult for students who learn science in a second language. Studies carried out in South Africa by Letsoalo (1996) and Doidge (1997) found that the language used in some African school science textbooks is too advanced for many of the pupils and these studies also reported that the communicative competence of some Year 12 (17+ years) ESL students may be comparable to that of Year 5 (10+ years) English-speaking students. Similarly, Heppner, Heppner and Leong (1997) studied the readability of biology materials and the reading ability of sixth form students (US 12th grade) in Brunei Darussalam and found that the reading materials supplied to the students were considerably more difficult than they were able to read comfortably. They found that about 10% of students have the readability level of US equivalent 12th grade while the majority of 90% have the depressingly low readability level of 9th grade (15%) and 7th grade (75%). Soyibo (1996) made comparison of three high-school biology textbooks used in the Caribbean Islands and found that the biology texts were difficult for the target students to read and understand.

In the local context, it has long been recognized that students encounter enormous problems learning science in a second language (Heppner et al., 1997; Mohiddin, 2007; Romaizah, 2009; Yong, 2003). Many secondary school teachers believe that students’ performance in science would be very much improved if they had a better proficiency of the English language. They argue that it is the language which is the main stumbling block for learning science rather than the science content itself.

In the government schools, students and teachers in the primary and secondary levels are provided with science textbooks. They rely heavily on them for learning and teaching science as they are the main reading material available for them. Studies had also shown that textbooks play a dominant role in science teaching (Driscoll, Moallem, Dick & Kirby, 1994) and in learning (Chiapetta, Sethna & Fillman, 1993). As the impact of science textbooks on curriculum is immense, it was decided that the suitability of the textbooks warrants an investigation. The textbooks are written in English whilst Bruneian students are ESL learners. An important question is: Are the science textbooks provided readily accessible to the students in terms of vocabulary and sentence structure? It is based on this issue that prompted the author to undertake this study to investigate whether there is a mismatch between the readability of science textbook and the reading ability of secondary students. The findings of this study will provide useful information on the impact of textbooks on science learning in secondary school. This is particularly significant as the new educational system for the 21st century or SPN21 places much emphasis on improving science education in the country.


The participants were 48 Grade 7 students from a government secondary school situated in the Brunei-Muara district, Brunei Darussalam. Of the sample there were 19 male and 29 female students. The average age of the sample was 12.3 years old.

Readability of Science Textbook

The science textbook entitled, ‘Secondary Science for Brunei Darussalam Book 1’ (CDD, 2008) was chosen for the study. This textbook is used by Grade 7 students in all the secondary schools throughout the state. It was designed and written by a review panel consisting of education officers and teachers who took considerable efforts to use language, materials and examples that are suitable and appropriate for the local context. The textbook was first published in 2008 in time for the implementation of the new educational system.

Readability Techniques

The readability of the science textbook was determined by using three different sets of tests. The tests involved counting the number of sentences as well as syllables in each of the three 100-word passages. In this case, the three passages selected for the tests were ‘Floating and sinking in water’ (p. 21), ‘Evaporation’ (p. 42) and ‘Photosynthesis’ (p. 178). All the three passages were assessed by the three tests in order to get a more accurate measurement of the readability of the science textbook.

When counting the syllables of text, it is recommended to say the words aloud. Some examples of syllable count are: stomach (3), together (3), leaf (1), system (2), surfaces (3), particle (3), enable (3). When counting numbers, symbols, initials, etc, one syllable is counted for each number or letter. For example: 1998 (4), 4.3 (3), H2O (3), USA (3), Fig.2 (2). For abbreviations (cm, mm, km, eg), they are counted as one syllable.

The three different sets of tests used to determine the readability of the textbook are given below. These are well established readability measures and they were chosen because ‘they are easy to apply, have reasonable validity and over the years have proved to be quite accurate’ (Wellington & Osborne, 2001, p. 142).

1. Gunning ‘FOG’ Readability test (Gunning, 1952 cited in Johnson & Johnson, 2009, p. 4). The three passages on ‘Floating and sinking in water,’ ‘Evaporation’ and ‘Photosynthesis’ were used to calculate the reading age using the Gunning formula.

2. Fry Readability Graph (Fry, 1977). Three passages similar to Test 1 were used. The Fry graph (Figure 1) was used to determine the reading age, in years.

3. Flesch-Kincaid Formula (cited in Johnson & Johnson, 2009, p. 4). Three passages similar to Test 1 were used. The Reading age was calculated according to the Flesch-Kincaid formula.
Students’ Reading Level

The cloze test was used to assess the reading ability of the students. In this study two passages on ‘How are cells organized?’ (pp. 123-125) and ‘Photosynthesis’ (pp. 178-181) were chosen and it consists of some 288 and 298 words respectively. The topics are new to the students as they have not been taught by the teachers. In both passages, the first and the last sentences were left intact. Deletion of words starts from the second sentence. This was done by counting from the first word of that sentence and every fifth word was deleted henceforth. The deleted words were replaced by blanks of the same length so as not to provide any clues about the size of the words. The respondents were required to supply the correct words, either exact or equivalent words, for the 50 blanks in the passage. In order to do this, they need to be able to follow the language pattern and vocabulary to fill the blanks. Students were given 15 minutes to fill in the blanks. The two tests were administered separately one week apart during the science lessons.

Figure 1. Fry graph for readability grade levels (Wellington & Osborne, 2001)
In scoring the cloze test, acceptable word method was used. Students were given full credit for giving equivalent words if exact words from the passage were otherwise not provided. A student received one point for each exact or acceptable word replacement. Words that were misspelled were also acceptable and student scored one point. The total number of points was multiplied by 2 to give the percentage correct obtained by a student. The guideline used for interpreting the score is presented in Table 1. Cloze results allow the researcher to establish the relative difficulty of the passage.
Table 1

Students’ Reading Level in Relation to Scores in the Cloze Test and Suitability of the Reading Materials (Wellington & Osborne, 2001)

Reading level


Suitability of reading materials


60-100% correct

Materials are too easy for students


40-59% correct

Materials are appropriate for students but need teachers’ support and guidance


0-39% correct

Material are too difficult for the students

Results and Discussion
Readability of Science Textbook

In order to estimate the reading age needed for the science textbook used by Grade 7 students, three tests were applied to three passages on the same topics. Results showed that the reading age obtained by Gunning and Fry formulae were 15 years while those obtained by Flesch-Kincaid formula was 13 years (Table 2). The average of three tests (Gunning, Fry, Flesch-Kincaid) was 14.3 years. This suggests that the Secondary Science Book 1 (CDD, 2008) has a reading level of 14.3 years. As the average age of students in Grade 7 class is 12 years old, many will find it difficult to get past the English in order to have a full understanding of concepts in a science lesson where the textbook requires a reading age of 14.3 years.

The Fry graph was also used to determine the relative difficulty of the vocabulary or sentence length of the passages. As the point obtained by Fry method was above the curve of the graph (Figure 1), i.e., top right, it appears that the science textbook has a higher than average vocabulary difficulty. This is an important factor that affects the readability of the textbook.
Table 2

Comparison of Readability of Science Textbook by Three Different Tests

Reading age





Floating and sinking in water
















Students’ Reading Level

The reading level of the students was determined using the cloze test. First, it was necessary to establish the reliability of the test. This was done by counting the number of correct words students had scored in the passage on ‘How are cells organized?’ The passage was divided into two parts each with 25 blanks. The number of correct words in each part was then converted to a percentage score. The reliability calculated using the Guttman split-half method was 0.82. The same procedure was carried out for the passage on ‘Photosynthesis.’ The reliability obtained was 0.87. This indicated that the tests were reliable and suitable for the study.

In terms of the reading level, it was found that the passage on ‘Photosynthesis’ is slightly more difficult for the students to read as the percentage distribution of those reading at frustration level was higher (68.1%) compared to the passage on ‘How are cells organised?’ (61.1%). When the results of the two passages were averaged out, it was found that none of the students was able to read at the independent level or that the text materials were too easy for them (Table 3). About 35% and 65% of students are categorized in the instructional and frustration levels respectively. This suggests that the Secondary Science Book 1 is suitable for 35% of the students but with some teachers’ support in terms of guidance and structured reading. A majority of students (65%) will find the texts too difficult. They will not be able to read and learn from the text materials presented in the textbook. Clearly, there is a mismatch between students’ reading level and readability of the science textbook. One way teachers can help this group of students is to rewrite the texts to make them easier and more understandable but comparable in content without compromising on the science concepts that students need to learn and grasp.
Table 3

Percentage of Students who were categorized as Independent, Instructional and Frustration Readers based on their Scores in the Cloze Test

Percentage of students

Reading level


How are cells organized?




60-100% correct





40-59% correct





0-39% correct




Correlation between Cloze Test and Students’ Performance

Students’ performance in science was determined by the percentage of marks they obtained in the monthly tests on three topics on ‘Classification’, ‘Forces’, and ‘Cell Structure and Organisation’. Result obtained for Pearson’s product-moment correlation showed that there was a positive significant association between cloze test and science performance (Table 4). This suggests that the reading level of the students is clearly a factor that influences students’ performance in science. In other words, students who scored high in the cloze test also performed better in science monthly tests and vice versa. Moreover, as much as 25% of the variance in students’ performance in science can be explained by their reading ability.

Table 4

Correlation Coefficient between Cloze Test readability and Science Performance scores

Performance in science

Cloze test


Correlation is significant at 0.01 level (2-tailed); **p<0.01
As teachers and students in Brunei Darussalam are provided with science textbooks, it will not be an understatement to assume that they rely heavily on these materials for teaching and learning science. One reason for the over dependent on textbooks is because these textbooks are specifically written for the SPA (Student Progress Assessment) science syllabus. As one teacher told the author that she uses the textbooks over 90 per cent of the time and would use other textbooks only as supplementary or reference material to increase her knowledge of certain subject areas or topics. This is not the case for students. As the textbooks are the only sole reading material provided, they rely on them 100 per cent of the time. An important question that needs to be considered is: Are the textbooks suitable in terms of the readability for the target students, or in order words, can Grade 7 students read and understand the text materials in Secondary Science Book 1 without much difficulty?

On analysis of the readability of the textbook Secondary Science Book 1 using Gunning, Fry and Flesch-Kincaid formulae, it was found that it has a reading level of 14.29 years. This is far above the average age of Grade 7 students of 12.3 years old. It seems that the textbook used by the students is too advanced and a majority of them will likely not be able to comfortably read and easily understand the texts, thus, gain little benefit from it. This concurred with Merzyn’s (1987) study in which he reported that the language of science is just too difficult for many students. Moreover, as the readability formulae also provide information on the difficulties relative to vocabulary and word difficulty of the sentences in texts, it appears that the science textbook has a higher than average vocabulary difficulty. It is suggested that those long and complex sentences in the texts be rewritten to make them shorter and more intelligible. Klare (1963) has shown that students prefer to read below their reading level and that they retain more in such circumstances. He recommended that the reading level of the texts should be two years below the students’ reading level so that the texts are more comprehensible to the students.

Results of the present study also show that a majority of students (64%) was found to be reading at the frustration level. This indicates that the text materials presented in the Secondary Science Book 1 are too difficult and that they will not be able to read and learn from the text materials alone without teachers’ assistance. As 35.4% of students were found to be reading at the instructional level, this means that the textbook is suitable for only slightly more than a third of students. The mismatch between students’ reading level and readability of the science textbook is further illustrated by the absence of students (0%) who are reading at the independent level.

Another interesting finding of the study is the relationship between students’ reading level and performance. Results show that there was a positive significant association between these aspects, and that is, students who have a higher reading level seemed to have better marks in science tests and vice versa.

Findings of the present study provide sufficient evidence which suggests that the readability of science textbooks is an important factor that affects students’ success and understanding of the texts, and which directly has an impact on their performance in science. As the readability of the science textbook is 2 years higher than the average age of the students, it is very doubtful that many students will be able to extract essential meanings from the texts. Moreover, many students will also become discouraged by the texts which they find difficult to read fluently and understand. As a textbook has been defined as “a book that no one would read unless they had to” (Johnson & Johnson, 2009), it is likely that many students will not be motivated to read the science textbook provided.
It is apparent that students face two major barriers when learning science: the readability of the text materials; and their reading ability. The two main ways in which teachers can help alleviate these problems are as follows:

Teachers should attempt to rewrite the texts so that the notes given to the students will be more readable and comprehensible to them. The texts should be written in short sentences and contain less difficult words and vocabulary.

Teachers should explain the difficult words and vocabulary found in the textbook to the students before the lesson so that the texts will be more intelligible and meaningful to them as they attempt to read them. These should be written on the board so that students can copy and write them down in their note books for reference.
The present study is exploratory in nature and more studies need to be carried out in order to enhance further the quantitative comparison of readability of the science textbooks and secondary students’ reading level. The studies should encompass other grade levels as well so that a more critical analysis could emerge from such endeavour.
Buriel, R. & Cardoza, D. (1988). Sociocultural correlates of achievement among three generations of Mexican American high school seniors. American Educational Research Journal, 25, 177-192.

Chiapetta, E. L., Sethna, G. H. & Fillman, D.A. (1993). Do middle school life science textbooks provide a balance of science literacy themes? Journal of Research in Science Teaching, 30, 787-797.

Curtis, S. & Millar, R. (1988). Language and conceptual understanding in science: a comparison of English and Asian speaking children. Research in Science and Technological Education, 6(1) 61-78.

Doidge, M. (1997). How readable is your biology textbook? Can you be sure? Proceedings of the Fifth Annual Meeting of the Southern African Association for Research in Science and Mathematics Education, (pp. 396-400). Sanders, M. (Ed.), Johannesburg, South Africa.

Driscoll, M. P., Moallem, M., Dick, W. & Kirby, E. (1994). How does the textbook contribute to learning in a middle school science class? Contemporary Educational Psychology, 19, 79-100.

Duran, B. J., Dugan, T. & Weffer, R. (1998). Language minority students in high school: the role of language in learning biology concepts. Science Education, 82(3), 311-341.

Duran, B. J. & Weffer, R. (1992). Immigrants’ aspirations, high school process, and academic outcomes. American Educational Research Journal, 29, 163-181.

Fry, E. (1977). Fry’s readability graph: clarification, validity and extension to level 17. Journal of Reading, 21, 242-252.

Garraway, G. B. (1994). Language, culture and attitude in mathematics and science learning: a review of the literature. Journal of Research and Development in Education, 27(2), 102-111.

Heppner, F. H., Heppner, M. C. & Leong, Y. P. (1997). Teachers’ estimate of, and measurements of students’ reading ability, and readability of text materials in English as a second language secondary Biology course. Journal of Applied Research in Education, 1(2), 31-39.

Johnson, C. & Johnson, K. (2009). Readability and reading ages of school science textbooks. Available: file://F:\Readability and reading ages of school science text-books.htm. Cited on 2.9.2009.

Klare, G. R. (1963). The measurement of readability. Iowa, USA: Iowa State University Press.

Lemke, J. (1997). Cognition, context and learning: a social semiotic perspective. In Kirschner, D. & Whitson, J. A. (Eds.), Situated cognition, semiotic and psychological perspectives, (pp. 37-56), Mahwah: Lawrence Erlbaum.

Letsoalo, M.B. (1996). Improving text for English second language biology pupils. Journal of Biological Education, 30(3), 184-186.

Merzyn, G. (1987). Language of school science. International Journal of Science Education, 43(3), 285-295.

Mohiddin bin Haji Noordin (2007). Students’ achievement in biology in public and private schools: Understanding the differences. Unpublished Masters Project, Universiti Brunei Darussalam.

Nielsen, F. & Fernandez, R. M. (1981). Hispanic students in American high schools: Background characteristics and achievement. Washington, DC: US Government Printing Office.

Ramorogo, G. & Wood-Robinson, C. (1995). Botswana children’s understanding of biology inheritance. Journal of Biological Education, 29(1), 59-71.

Richardson, J. & Lock, R. (1995). The readability of selected A-level biology examination papers. Journal of Biological Education, 27(3), 205-212.

Rollnick, M. (1999). The influence of language on second language teaching and learning science. In Clements, M.A. (Ken) & Leong, Y.P. (Eds.), Cultural and language aspects of science, mathematics and technical education,(pp. 123-132). Gadong: Universiti Brunei Darussalam.

Romaizah Salleh. (2009). Brunei primary pupils’ ideas of water cycle: effects of culture and language. Jurnal Pendidikan, 14, 70-80.

Rosenthal, J. W. (1996). Teaching science to language minority students. Clevedon: Multilingual Matters.

Rutherford, M. (1993, June). Making scientific language accessible to science learners. Paper presented at the first Annual meeting of the Southern African Association for Research in Mathematics and Science Education, Grahamstown, South Africa.

Santa, C. M., & Alverman, D. E. (1991). Science Learning: Process and applications. Newark, DE: International Reading Associations.

CDD (2008). Secondary Science for Brunei Darussalam Book 1. Brunei Darussalam Curriculum Development Department, Ministry of Education.

Soyibo, K. (1996). A comparison of communication strategies among three Carribbean high-school biology textbooks. Journal of Biological Education, 30(3), 190-194.

Wellington, J. & Osborne, J. (2001). Language and literacy and science education. Buckingham, England: Open University Press.

Yong, B. C. S. (2003). Language problems in the learning of biology through the medium of English, Journal of Applied Research in Education, 7(1), 97-104.

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