5.4.1 The Baseline Measures
Scoring criteria for the (BPVS) British Picture Vocabulary Scale
In the BPVS the children had to point to one out of four pictures to indicate the word spoken
by the experimenter. The basal point was where there were 6 consecutive correct responses
and the ceiling was where out of 6 consecutive responses there were 4 errors. Children’s raw
scores in the BPVS were transformed into standardised scores. The standardised scores were
coded into low existing vocabulary and high existing vocabulary. The splitting into high and
low was made according to a stem and leaf chart where half of the sample belonged to one
level and the other half belonged to the other level. Low existing vocabulary was given if a
child scored less than 84 (standardised score) and high existing vocabulary was given if a
child scored more than 85 (standardised score). The cut-off point was 1 standard deviation
+/- the mean.
Scoring of the Test of Non-word Repetition: A test ofphonological working memory
The test administrator scores each of the 40 repetition attempts as either correct or incorrect,
and calculates a single score at the end of the test which corresponds to the total number of
correct repetitions. Each child could get a score from 1-40. Children’s raw scores in the
phonological memory test were transformed into the standardised scores'. The standardised
score was coded into low level phonological memory and high level phonological memory.
The splitting into high and low was made according to a stem and leaf chart where half of
the sample belonged to one level and the other half belonged to the other level. Low
phonological memory was given if a child scored less than 127 (standardised score) and high
phonological memory was given if a child scored more than 130 (standardised score). The
cut off point was 2 standard deviations +/- the mean.
5.4.1.1 British Picture Vocabulary Scale
Table 5.4 presents the groups performances on the British picture vocabulary scale. The table
shows that children’s existing vocabulary from all the different subgroups (age and group)
did not differ.
1 High scores in the phonological working memory test raise concern about the test.