M. D. CLARK
VL2 Background Questionnaire
The approved VL2 Background Questionnaire was adminis-
tered to all participants. This measure collected information on
language preference and information related to their hearing loss.
PDT
The Koo et al., (2008) Phoneme Detection Test was admin-
istered to all participants. The test, includes a set of four prac-
tice trials to show that phonemic units, rather than orthographic
units, are the focus of each trial. Participants were instructed to
respond as fast and as accurately as possible. Responses are
recorded by pressing 1 on the keyboard if the word includes the
target phoneme or 2 if it does not have the target phoneme. Five
blocks of 30 items are included. Half of the items have the tar-
get phoneme in either initial, medial, or final position within
the word while the other half of the items was foils. Order of
blocks is counterbalanced across participants.
VL2-SLPA
All participants completed the Miller et al. (2010) picture
measure of PA. Recognition of each picture was tested prior to
the start of the test to insure that participants were familiar with
the words. If a picture was not named correctly, participants
were retested on items that they had gotten incorrect. Next, they
were instructed to pick the two pictures where the initial (final)
sound was the same. Two sample items were presented, two for
initial sounds and two for final sounds. If participants did not
select the two phonologically matching pictures, they were told
which two were correct and why. Responses were recorded on
a separate coding form that recorded which two pictures were
selected. Each response was timed using a stopwatch and the
reaction time was recorded on the coding form. After complet-
ing each trial, participants pressed the space bar to continue to
the next item.
Results
Percentage scores were used to compare the PDT and the
VL2-SLPA measures.
The range of the PDT was from 2% to 94% correct, with an
average of 61% correct per block and a standard deviation of
15.1 per block (raw mean per block = 18.7, SD 3.7). The range
of the VL2-SLPA was from 25% to 100% correct, with an av-
erage of 54.8% correct and a standard deviation of 18.5% (raw
mean = 6.6, SD = 2.2). The correlation between the PDT and
the VL2-SLPA was r = .54, demonstrating a strong correlation
between these two measures (Cohen, 1988.) Using a dependent
t test, the PDT was found to have a higher percentage correct
than the VL2-SLPA, t (41) = −2.34, p = .02.
On the VL2-SLPA, participants could select either a phono-
logical match or an orthographic match. Using a dependent t
test with the raw scores on the VL2-SLPA, it was found that
participants were more likely to select the phonological match
for initial phonemes (mean = 2.57, SD = 1.10) than the ortho-
graphic match (mean = 1.94, SD = .85), t (46) = 2.72, p = .009.
They were also more likely to select the phonological match for
final phonemes (mean = 3.27, SD = 1.21) than the orthographic
match (mean = 1.90, SD = .1.00), t (40) = 4.38, p = .000.
Discussion
The VL2-SLPA showed strong convergent validity with the
PDT. The strong correlation demonstrates that both measures
can provide an indication of a deaf participant’s PA without a
verbal response. The difference between the PDT and the VL2-
SLPA can be explained by the difference in the number of re-
sponses for each measure. Participants on the PDT have a 50/50
chance of getting the correct response, even if they are guessing.
The VL2-SLPA has four response choices, which reduces the
probability of getting the correct response on a simple guess. In
addition, the VL2-SLPA can evaluate not only PA but gives
participants an option to select an orthographic choice. These
two sub-scores may allow researchers to identify participants
who prefer an orthographic response.
Watching participants in this study was painful as they
struggled to pick the correct match. Hearing pilot participants
took about five minutes to complete this task, remember it is
only 12 items. Deaf participants often took 20 minutes to com-
plete this task. The importance placed on phonology is clearly
understood by deaf individuals and they wanted to do well on
this task. One might hypothesize that they would think, “what-
ever—I will just guess”. This guessing strategy was clearly not
the case. Some participants could easily do the task and scored
100% correct. Others struggled and still were unable to select
the correct item.
These participants did not substitute an orthographic strategy
for a phonological strategy. They understood the goal of the
task, obtaining an overall average of a bit over 50% of the items
correct. Currently, this VL2-SLPA measure is being used to
collect data on younger readers in the VL2 International Read-
ing Project and it will be interesting to see if they select an
orthographic strategy in this task. Bélanger, Baum, and May-
berry (2011) found that only skilled deaf readers used a phono-
logical code while less skilled deaf readers used an ortho-
graphic code. The participants in this study tend to be skilled
deaf readers as they are college students. Therefore, the results
of the ongoing study with younger and less skilled deaf readers
will help to answer this question.
Future research can compare results on the VL2-SLPA to
more traditional measures like the TOPA or PAT 2. If deaf
phonological users show higher levels of PA on the VL2-SLPA
than the tests that typically require spoken responses, it will
support the ideas of Conrad (1979) that skilled deaf readers
have inner speech that they used to decode written texts even if
their spoken responses may not be showing this effect. One
would need to select these participants based on the PA abilities
rather than their reading skills, as we have evidence that skilled
deaf readers may or may not use spoken language phonology
(Allen, Clark, del Giudice, Koo, Lieberman, Mayberry, &
Miller, 2009; Bélanger, Baum, & Mayberry, 2011, Clark, Gil-
bert, & Anderson, 2011; Miller & Clark, 2011).
The VL2-SLPA measure can be used to evaluate spoken
language phonology for anyone, hearing or deaf—adult or child.
Future analysis of the VL2 International Reading Project will
provide data on this comparison, with information on 3rd and
4th graders, 6th and 7th graders, and 9th and 10th graders who
are both hearing and deaf. The measure is easy to administer
and can be obtained through the VL2 Toolkit Project.
Acknowledgements
This work was partially supported by National Science
Foundation under grant number SBE-1041725 and from a
Small Grant to Jessica Feldman from the Gallaudet Research
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