Science lessons often cover abstract ideas which can cause problems for ESL students. Photo: May Tse

Why many students have trouble grasping abstract science concepts

My doctoral studies grew out of my frustrations as a science teacher. In 2002, I was required to teach Grade 6 students both mathematics and science at the Hong Kong International School.

Of the large number of English as a Second Language (ESL) students from local schools, I found many demonstrated a poor understanding of scientific concepts and content, even though they continued to do well in mathematics. Yet they had scored well in the school entrance test as well as the pre-S1 achievement test (HKAT).

As I began analysing their response to questions, a pattern began to emerge. The students usually had trouble understanding questions that dealt with abstract concepts (gravity and refraction, for example), and the logical reasoning of "if-then-else" used language filled with hypothetical statements and inference.

Later, while I was teaching biology in Grades 10 to 12, I found that students in some classes had more trouble understanding the same concepts than others because of a difference in language proficiency, and it forced me to teach each class differently.

For a biology teacher trained to focus on teaching "content", this proved challenging and I came to realise the complexity of addressing the language needs of students in a science classroom. With encouragement from my principal Linda Anderson (now the associate head of school at HKIS), I began researching ways I could address the language needs of the ESL students.

Much research has been done on problems faced by ESL students in Hong Kong, both in English medium instruction (EMI) and international schools. Although the EMI schools satisfy the criteria for students meeting minimum language requirements, teachers who are able to teach proficiently in English are concerned about students' ability to cope with "content" subjects, especially science. A third of students from EMI schools interviewed said they found learning abstract ideas being taught in English difficult because they didn't understand the vocabulary and couldn't grasp the grammatical structures. Half the interviewed students said their teachers were more concerned with conveying the content than making sure they understood it. They also said English and science teachers could do more to help them adapt to instruction in English.


Learning of science involves both the learning of concepts and the language of science. So why do students find learning scientific language difficult?

British linguist Michael Halliday explains that scientific language consists largely of nouns that were converted from verbs and adjectives. For instance, terms such as refraction or gravity describe physical phenomena that are the result of a series of events.

Thus the verb "to move" is transformed into the noun "motion". Then this abstract concept is categorised, for example, into linear motion, periodic motion and orbital motion. When the class is required to compare linear motion with orbital motion, this is exactly what ESL students find difficult.

Researcher P.L. Gardner concludes that the words that students need in order to grasp abstract concepts are the very words they have the most difficulty with.


Furthermore, the explanation of abstract scientific concepts uses words that express a logical progression such as "if-then", "either-or", "neither-nor" and "consequently". Conjunctions help express a sequence of events. Because students are required to draw conclusions based on their observations, they have to understand terms such as "compare-contrast", "cause-effect" and "problem-solution".

Recent evidence suggests that it doesn't take long for students with little English proficiency to be able to use English in social situations in classrooms and playgrounds.


However, conversational fluency and grade-level performance in the classroom are two different things. Empirical research has repeatedly shown that ESL learners need five to seven years to catch up with native-speaking peers in academic contexts. Parents sometimes have a mistaken belief that science grades will improve if an ESL student has acquired conversational fluency.

But making a list of the "jargon" in each science unit and explaining it will go a long way in helping students understand such abstract terms. And we science teachers would be happy to check these lists.

Anjali Hazari teaches IB and IGCSE biology at the French International School in Hong Kong

This article appeared in the South China Morning Post print edition as: Why many students have trouble grasping abstract science concepts