Supporting data for “Comparing the effects of inhibitory control on Chinese reading comprehension between learners of Chinese as a first and second language”

To have a comprehensive understanding of the relationship between inhibitory control and reading comprehension in CSL secondary students, 107 Form 5 CSL students (49 girls and 48 boys), aged 16 to 18 years, were recruited from one key secondary school in Shanghai that admitted Xinjiang students.

Considering the lag of Xinjiang students in academic development, 142 Form 5 Chinese native students (65 girls and 77 boys) were recruited from another secondary school, a district key school (one level lower than city key schools), as a comparison group.

1 Chinese reading comprehension

In this study, the Chinese language assessment of the Territory-wide System Assessment (TSA) examination was specially selected for reading comprehension measurement. This measure was selected for three reasons. First, the TSA test is a standardized test administered at the territory level in Hong Kong. It provides comprehensive and objective information about the learning process of students in the Chinese language, English language, and Mathematics, assessing the strengths and weaknesses of students in the different subjects. Despite the difference in education systems in Shanghai and Hong Kong, both systems have set similar goals of Chinese reading comprehension for students, according to the comparison research by Ho (2006). Second, the TSA test has a high number of clear categories for assessment. The Chinese language test, which adopts a measuring system with diverse question types, could provide sufficiently objective data about reading comprehension performance. Third, regarding the lag of Xinjiang students in the Chinese language compared to their Chinese peers, it is suitable to measure their Chinese literacy with the TSA test.

There were two articles in the test and students were asked to answer all the questions according to the contexts. It took approximately 30 minutes for students to complete the whole test. A mark was scored for each correct response.

2 Orthographic knowledge

Orthographic knowledge was measured by two subtests: a lexical decision task and an orthographic choice in context task.

A. The lexical decision task (Wang et al., 2003) aimed to test students’ orthographic awareness of the internal structure in Chinese characters. Participants needed to determine whether the presented pattern was a real character, requiring their knowledge of manipulations of structural complexity (left-right or top-bottom) and component compositional relationship (i.e., single or compound character). Both real and pseudo characters were designed with different stimuli. For the pseudo compound characters, each of the characters represented one of three combinations: (i) illegal component and legal position, (ii) legal component and illegal position, (iii) illegal component and illegal position. For the real compound characters, each character represented one of the four combinations of the two structural complexities (left-right or top-bottom) and two frequency effects (high- and low-frequency). The frequency effects of words were controlled by literature (Lee, 2000). There were 20 items for each type, rendering a total of 160 items. It took an average of five minutes for students to complete the whole test. One point was given for each correct response.

B. The orthographic choice in context task was modified from the study of Leong, Tse, Loh, and Ki (2011) to measure students’ orthographic knowledge of words in context. Each question asks participants to select the correct answer from four two-character words provided to complete the meaning of the sentence. Based on the similarity of orthography or phonology, there were three kinds of two-word character distractors: (a) regular consistent, (b) regular inconsistent, (c) exception real or pseudowords. There were 20 items, and it took an average of five minutes for students to complete the whole test. One mark was scored for each correct response, yielding a maximum of 20 points for the entire task.

C. Phonetic awareness was modified from the study of Shu, Anderson, and Wu (2000) to measure students’ orthographic knowledge of phonetics within the characters. Each question asked participants to select the correct answer from two two-character words with different phonetics having the same pronunciation. There were 20 items that took an average of five minutes for students to complete the whole test. One mark was scored for each correct response, yielding a maximum of 20 points for the entire task.

3 Morphological knowledge

The morphological knowledge assessment included two subtests, the morpheme recognition task and the morpheme discrimination test, which were modified from the study of Ku and Anderson (2003).

A. The morpheme recognition task assessed students’ knowledge of morphological relationships between the two characters which formed one word. Participants were asked to judge whether the second word’s meaning was derived from the first one. There were 20 items, and it took an average of five minutes for students to complete the whole test. One mark was given for each correct response, yielding a maximum of 20 points for the entire task.

B. A morpheme discrimination test was used to measure the understanding of students of the word parts with different meanings in different two-character words. Each test item consisted of three two-character words that shared the same morpheme, with the morpheme in one word carrying a different meaning. Participants were asked to identify the word with the morpheme that was inconsistent with the meaning of the others. Considering the content of the current Chinese curriculum for CSL students, some modification of the word selection was made after analysis by experienced secondary school teachers. It took an average of five minutes for students to complete the whole test. One mark was scored for each correct response, yielding a maximum of 20 points for the entire task.

4 Inhibitory control

In this study, inhibitory control, as one important aspect of EF, was measured by the subtest of Delis-Kaplan Executive Function System (D-KEFS) called the Color-Word Interference Test (Delis et al., 2001).

The Color-Word Interference Test was a computerized task measuring the response inhibition of participants. Participants were asked to name the color of the characters presented on the computer screen. There were three contingencies: (1) In the baseline condition, a color patch of either blue, red, green, or black; (2) In the congruent condition, the color word is presented in a congruent color, for example, the character 藍 in blue; (3) In the incongruent condition, the color word is presented in incongruent color, for example, the character 藍 in red. The inhibition score was analyzed from the difference in accuracy and response time (RT) in congruent and incongruent conditions. The length of the task was estimated to be 10 minutes. There were 18 items for each condition, rendering a total of 54 items, i.e., three points for each correct item.

5 Control measures

1 Nonverbal intelligence

This study applied the standardized test of Raven’s Standard Progress Matrices (Raven, 1958), which included five sets with 12 items each. In each set of tests, students were asked to choose one correct image from six to eight alternatives according to the missing part of the target visual matrix. For example, the fourth image should be selected as the correct answer according to the pattern of the left image (see Image 1). It took an average of 10 minutes for students to finish the whole test. One point was given for each correct response.

Image 1 Example of the standardized test of Raven’s Standard Progress

2 Vocabulary

This study applied a standardized assessment of the receptive vocabulary of the Peabody Picture Vocabulary Test (Dunn & Dunn, 2007) in the Chinese version (Lu & Liu, 1998), which consisted of 120 words of increasing difficulties. In the test, students were asked to select one of four pictures that best described the word's meaning according to the word. It took an average of 20 minutes for students to complete the whole test, unless the student failed to read 15 words consecutively, which would lead to instant termination of the test. One point was given for each correct response.