Conclusiones Respecto a la Aplicación de la Fase 2

Was there a significant increase in the participant’s ability to correctly identify the correct picture corresponding with the target word?

Pictures used in the receptive vocabulary subtest were presented in sets of four with one representing the target word and three distractors. Pictures were sourced directly from the books used for the intervention with background illustrations edited out. The requirement for a correct response was to point to the picture representing the correct answer. The receptive subtest was scored out of a possible 32 as each question was either marked as correct (1) or incorrect (0).

Raw Scores for individual subtest per participant (Experimental and control groups analysed

separately)

Sum of Pre test Scores per item (See appendices H,

I & J)

Sum of Post test scores per item (See appendices H,

I & J)

Sum of pre-test raw scores of all participants within

the group (Experimental or

control)

Sum of post-test raw scores of all participants within

the group (Experimental or

control)

Percentage (%) increase in scores between pre and post-test = % gain

86

The following table provides the percentage gain for the experimental and control groups for the receptive vocabulary subtest, as well as the p value which indicates the significance of the results.

Table 5: Receptive Vocabulary - Percentage gain comparison for experimental and control

group conditions

Experimental Gain Control Gain P Value

Mean 13.8 (SD 14.1) 2.5 (SD 14.5)

0.01

Median 12.5 6.25

When examining this data, one can see that there was an increase in the scores of the experimental group as well as the control group. The results of the subtest for this study indicate a 13.8% increase in the experimental group’s abilities to correctly identify the corresponding picture for a corresponding word. This is in line with previous studies which report similar gains of 10 – 15% when children are exposed to stories three or four times (Elley, 1989 and Biemiller, 2006). These results indicate that the method under investigation is successful in increasing the breadth of children’s vocabulary. This is a positive sign towards the purpose of the study as it has been shown that knowledge of the word at a receptive level is a precursor to improving depth of word knowledge (Coyne et al, 2009; Justice et al, 2005). Depth of knowledge could then further be targeted when the child hears the word again within a context and can build on their personal knowledge they have already built up of that word.

A Wilcoxon Signed Rank Test showed that the proposed intervention produced significant results (z = 2.51; p = 0.01) in the improvement of children’s abilities to accurately identify a picture that corresponds to a target word. The significance value indicates that the hypothesis that listening to story tapes would increase receptive vocabulary is correct.

The figure below represents the percentage gains for experimental and control groups in terms of receptive vocabulary. This provides a pictorial representation of results which will allow for a better understanding of the results as one can visualise the percentage gains for each group. The dark line in the box graph represents the mean for each group with the scatter of results indicated by the upper and lower edge of each box.

87 40 20 0 -20 Experimental Control

Figure 7: Percentage gain for Receptive Vocabulary. Comparison between percentage gains

for experimental and control group conditions

% Ga ins f or e xpe ri menta l and contr o l gr ou ps ( R ec epti ve Voc abular y)

88

When considering the differences between the sexes as shown in the figure below, it appears as if the boys outperformed the girls in the % gains that were made in correctly identifying the target picture. This could be interpreted as the girl’s having a higher initial knowledge of vocabulary prior to the interventions which would allow them to learn a higher number of words based on their ability to draw inferences from the surrounding text. A higher prior knowledge of vocabulary is also linked to a child’s ability to acquire new words with a few exposures (Justice et al, 2005).

20 10 0 -20

Experimental Control Experimental Control

Figure 8: Receptive Vocabulary. Comparison of percentage gains between girls and boys

It could be argued that receptive vocabulary scores could have been affected by the fact that the Sentence Completion subtest used the same pictures as the target words in the Receptive Vocabulary subtest and caused a learning effect (Meline, 2012). However, this was compensated for by reusing some of the pictures as distracters for other questions and therefore some of the pictures occurred twice within the receptive vocabulary subtest.

“Does Listening to story tapes improve children’s receptive vocabulary?”

The results of this study indicate that listening to story tapes does in fact increase children’s ability to understand new words. Previous research comparing static book reading with video story books indicated that there was no significant difference in results depending on the

% Ga ins be twe en gir ls a nd boys ( R ec epti ve Voc abular y)

89

methods for teaching receptive vocabulary (Verhallen & Bus, 2010). Implications of this are that regardless of the intervention method, receptive vocabulary development can be built on by hearing stories. This has good implications for vocabulary development as the accepted theory is that receptive vocabulary develops before expressive vocabulary (Coyne et al, 2009; Justice et al, 2005). Breadth of word learning increases through exposure to new words used by advanced speakers of a language and the incremental increase in vocabulary depth increases as well (Christ et al, 2010) which supports the results found in this study.