3. Experiment 2

3.1 Method

3.1.1 Participants

The participants included 93 children from an elementary school in a working class neighborhood in Beijing, China. The initial testing took place in the middle of the spring semester, when the children were in Grades 1 (43 children: 24 boys, 19 girls) and 2 (50 children: 25 boys, 25 girls). The average ages were 6;4 and 7;3 at this time. The children were followed up about 7 months later, in the middle of the fall semester of Grades 2 and 3. All the children were native speakers of Chinese and did not have any obvious cognitive or developmental delays.

3.1.2 Materials and procedure

The children participating in Experiment 2 also received a morphological judgment task. In this task, the experimenter presented a pair of compound words to the child, for example, 门铃 menling (door bell: doorbell) and 门票menpiao(door ticket: ticket), and pointed out that the two compound words shared a syllable that had the same pronunciation, for example, men. The experimenter then asked the child to judge whether these two syllables had the same meaning. Note that there were several differences between this task and the task used in Experiment 1. First, pictures were not used in this task because the children were older. Second, the items in this task included both concrete and abstract words, which are developmentally appropriate for older children.

The morphological judgment task included 32 test items. Each test item consisted of a pair of compound words sharing the same morpheme. The characteristics of these items are described in detail below. The test items are presented in Appendix A. The task also included 40 filler items, each containing a pair of compound words sharing homophones. The homophonous morphemes had the same pronunciation but different meanings, for example, 风扇 fengshan (wind fan: fan) and 蜂蜜 fengmi (bee honey: honey). Because the time interval between test administrations was relatively short, different test and filler items were used at the two testing times. At each testing time, different types of test items and filler items were mixed together and presented in a randomized order. Children were tested individually in a quiet room by a trained graduate student majoring in psychology. The reliability (α) of the task was 0.97 at Time 1 and 0.92 at Time 2.

SEMANTIC RELATEDNESS. The test items were divided into two levels of semantic relatedness, with 16 items in each condition. The two words in each item in the high semantic relatedness condition were closely related in meaning as whole words, for example, 电视 dianshi (electric vision: television) and 电话dianhua (electric talk: telephone), and the words in each item in the low semantic relatedness condition were distant in meaning, for example, 假山 jiashan (artifical mountain: rockwork) and 假发 jiafa (artificial hair: wig). Twenty psychology majors at Beijing Normal University evaluated the semantic relatedness of these word pairs on the same 7-point scale as in Experiment 1. The average rating of items of high semantic relatedness was 4.75 at Time 1 and 4.16 at Time 2, t (30)= 1.83, p > .05. The average rating of the items of low semantic relatedness was 2.03 at Time 1 and 2.17 at Time 2, t (30) = 0.55, p > .1. The difference between the ratings of items of high semantic relatedness and the ratings of items of low semantic relatedness was highly significant at both testing times, t (30) = 8.87, p <.001 at Time 1, and t (30) = 7.04, p < .001 at Time 2.

MORPHEME TYPE. Because of an oversight in research design, the number of free and bound morphemes varied slightly at the two testing times. At Time 1, there were nine free morphemes and 7 bound morphemes in each semantic relatedness condition. At Time 2, there were 8 free morphemes and 8 bound morphemes within each semantic relatedness condition. A free morpheme, for example, “腰” in 腰果 yaoguo (waist fruit: cashew) and 腰带 yaodai (waist strap: waistband) can appear as an independent word, for example, 他腰疼 (His waist hurt). A bound morpheme, for example, “厨” in 厨房 chufang (cook room: kitchen) and 厨师 chushi (cook master: cook), cannot stand on its own. Twenty linguistics majors rated morpheme type on a 3-point scale adopted from Chen and Zheng (2000): where 1 = a morpheme is always free, 2 = a morpheme is sometimes free, and 3 = a morpheme is always bound. The target morphemes in the test items received consistent ratings from all the evaluators, either as free morphemes or bound morphemes.

ITEM FAMILIARITY. Only words familiar to the children in spoken

language were included in the morphological judgment task. Familiarity was first determined based on two corpora of Chinese preschoolers’ spoken vocabulary created by the first author (Hao et al., 2008, 2011). In addition, familiarity of the test items was rated by 12 first-grade teachers from two different primary schools in the same neighborhood on a 7-point scale, where 1 = extremely unfamiliar and 7 = extremely familiar. The average ratings of words for high semantic relatedness at Time 1, Time 2, and for low semantic relatedness at Time 1 and 2 were 5.50, 5.45, 5.54, and 5.46 respectively. The difference among the four conditions was not significant, F (3, 124) = 0.69, p > .1. The participating children had not learned the characters used for these words in school.

3.2 Results and Discussion

The descriptive statistics for the test items are presented in Table 2. The filler items were not analyzed. Participants who scored above 95% correct on the test items but less than 25% correct on the filler items were eliminated from data analysis because their answers appeared to have been determined by phonological similarity. That is, they may have given a positive answer simply because the target morphemes shared the same pronunciation. The number of children removed from the first and second grade groups were 7 and 2, respectively.

As shown in Table 2, the younger cohort performed close to the chance level (50%) at the low semantic relatedness condition, especially when the target morpheme was bound. In most cases, children performed better in the high semantic relatedness condition than in the low semantic relatedness condition, and better when the target morpheme was free than when it was bound. Their performance also increased with age/grade level and from Time 1 to Time 2.

A2 (Semantic Relatedness) x 2 (Morpheme Type) x 2 (Testing Time) x 2(Age) repeated-measure analysis of variance was conducted on the test items. Semantic relatedness, morpheme type, and testing time were within-subject factors, and age was a between-subject factor. There was a very large effect of semantic relatedness, F (1, 77) = 137.50, p < .001, η2 = 0.641. This effect showed that children’s performance on the morphological judgment task was strongly influenced by semantic relatedness between words. As we expected, it is relatively easy to recognize the common morpheme when words are closely related in meaning, but the difficulty level increases when the word meanings are dissimilar. There was also a significant main effect of age, F (1, 77) = 11.26, p = .001, η2 = 0.128, and a significant main effect of time, F (1, 77) = 7.56, p < .05, η2 = 0.089. These findings again support our hypothesis that, in general, children’s homophone awareness increases with age.

Table 2. Mean proportion (standard deviation) as a function of semantic relatedness, morpheme type, testing time, and cohort in Experiment 2

The interaction between semantic relatedness and age was significant, F(1, 77) = 11.96, p = .001, η2 = 0.134. Further analysis revealed that at both testing times, the two cohorts performed largely similarly on items of high semantic relatedness, but the older cohort scored significantly higher on items of low semantic relatedness, F (1, 77) =11.48, p < .001, η2 = 0.130 at Time 1, and F (1, 77) = 12.88, p < .001, η2 = 0.143 at Time 2. The interaction between semantic relatedness and testing time was also significant, F (1, 77) = 25.48, p < .001, η2= 0.249. Although there was no difference in performance from Time 1 to Time 2 on the items of high semantic relatedness for either cohort, both cohorts improved significantly on the items of low semantic relatedness during the time period, F (1, 33) = 11.33, p < .001, η2 = 0.256 for the younger cohort, and F (1, 44) = 12.05, p < .001, η2 = 0.215 for the older cohort. These significant interactions are illustrated in Figure 1. Thus, in Grade 1, Chinese children are already capable of identifying morphemes in closely related compounds, and consequently, there is little improvement with age/time. By contrast, children continue to develop the ability to identify shared morphemes in semantically dissimilar words in the early primary grades.

There was a significant main effect of morpheme type, F (1, 77) = 32.66, p < .001,η2 = 0.298, which confirms our hypothesis that children are more aware of free morphemes than bound morphemes. It is interesting that neither the interaction between morpheme type and age nor the interaction between morpheme type and time was significant. The three-way interaction between morpheme type, age, and time was also not significant. These results, shown in Figure 2, suggest that awareness of free morphemes and awareness of bound morphemes develop in a similar fashion in the two cohorts.

We observed a significant three-way interaction among semantic relatedness, morpheme type, and time (see Figure 3), F (1, 77) = 5.74, p < .05, η2 = 0.069. Further analysis showed that at Time 1, the effect of morpheme type on morpheme identification did not vary across the two semantic relatedness conditions. By contrast, at Time 2, children performed similarly on free and bound morphemes in the high semantic relatedness condition, but they performed better on free morphemes than bound morphemes in the low semantic relatedness condition, F(1, 77) = 16.92, p < .001, η2 = 0.180. That is to say, children in Grades 2 and 3 appear to have acquired the ability to identify bound morphemes in semantically similar words. However, they still have difficulty in recognizing bound morphemes in semantically dissimilar words.