Sampling
procedures
In 1998, 2872 children from 252 schools were in the final samples
to participate in national monitoring. About half were in year
4, the other half in year 8. At each level, 120 schools were selected
randomly from national lists of state, integrated and private schools
teaching at that level, with their probability of selection proportional
to the number of students enrolled in the level. The process used
ensured that each region was fairly represented. Schools with fewer
than four students enrolled at the given level were excluded, as
were special schools and Kura Kaupapa schools (by mutual
agreement, the latter will be included in the year 8 assessments
from 1999 onwards).
Early
in May 1998, the Ministry of Education provided computer
files containing lists of eligible schools with year 4 and
year 8 students, organised by region and district, including
year 4 and year 8 roll numbers drawn from school statistical
returns based on enrolments at 1 March 1998.
From
these lists, we randomly selected 120 schools with year 4 students
and 120 schools with year 8 students. Schools with four students
in year 4 or 8 had about a one percent chance of being selected,
while some of the largest intermediate (year 7 and 8) schools
had a more than 90 percent chance of inclusion. In the three
cases where the same school was chosen at both year 4 and year
8 level, a replacement year 4 school of similar size was chosen
from the same region and district, type and size of school.
Pairing
small schools
At the year 8 level, 5 of the 120 chosen schools had less than
12 year 8 students. For each of these schools, we identified the
nearest small school which met our criteria to be paired with the
first school. Wherever possible, schools with 8 to 11 students
were paired with schools with 4 to 7 students, and vice versa.
However, the travelling distances between the schools were also
taken into account. Similar pairing procedures were followed at
the year 4 level, creating 7 pairs of schools at this level.
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Contacting
schools
During the second and third weeks of May, we attempted to telephone
the principals or acting principals of all schools in the year
8 sample. We made contact with all schools during that period,
where necessary leaving messages for the principal to return our
call on the Project's 0800 number.
In
our telephone calls with the principals, we briefly explained
the purpose of national monitoring, the safeguards for schools
and students, and the practical demands participation would
make on schools and students. We informed the principals about
the materials which would be arriving in the school (a copy
of a 15 minute NEMP videotape plus copies for all staff and
trustees of the NEMP brochure and detailed booklet for sample
schools). We asked the principals to consult with their staff
and Board of Trustees and confirm their participation by the
end of June.
A
similar procedure was followed in July with the principals
of the schools selected in the year 4 sample, and they were
asked to respond to the invitation by the end of August.
Response
from schools
Of the 254 schools invited to participate, 252 agreed. One school
declined to participate because all of its year 8 students were
in a Mäori immersion programme. A school in the year 4 sample
gave space constraints as its reason for not participating
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Sampling
of students
With their confirmation of participation, each school sent a list
of the names of all year 4 or year 8 students on their roll. Using
computer generated random numbers, we randomly selected the required
number of students (12, or 4 plus 8 in a pair of small schools),
at the same time clustering them into random groups of four students.
The schools were then sent a list of their selected students and
invited to inform us if special care would be needed in assessing
any of those children (e.g. children with disabilities or limited
skills in English).
At
the year 8 level, we received about 94 comments from schools
about particular students. In 45 cases, we randomly selected
replacement students because the children initially selected
had left the school between the time the roll was provided
and the start of the assessment programme in the school, or
were expected to be away throughout the assessment week. The
remaining 49 comments concerned children with special needs.
Each such child was discussed with the school and a decision
agreed. Six students were replaced because they were very recent
immigrants who had extremely limited English language skills.
Eight students were replaced because they had disabilities
of such seriousness that it was agreed that the students would
be placed at emotional risk if they participated. Participation
was agreed upon for the remaining 35 students, but a special
note was prepared to give additional guidance to the teachers
who would assess them.
In
the corresponding operation at year 4 level, we received 81
comments from schools about particular students. Twenty-seven
children originally selected needed to be replaced because
they had left the school. Ten students were mentioned because
of their ESOL status. Of these, one very recent immigrant was
replaced. Eight students were mentioned because they were participants
in total immersion Mäori language programmes. Assessment
in Mäori was arranged for the seven immersion students
at one school, and one immersion student was replaced. Other
special needs were mentioned for 44 children, and 10 of these
children were replaced (4 because of very severe physical disabilities,
and 6 because of concerns about their ability to cope with
the assessment situation). Special notes for the assessing
teachers were made about 43 children retained in the sample.
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Communication
with parents
Following these discussions with the school, Project staff prepared
letters to all of the parents, including a copy of the NEMP brochure,
and asked the schools to address the letters and mail them. Parents
were told they could obtain further information from Project staff
(using an 0800 number) or their school principal, and advised that
they had the right to ask that their child be excluded from the
assessment.
Our
0800 number was monitored in evenings, as well as during the
day, for two weeks following each mailing of letters to parents.
At
the year 8 level, we received about 20 phone calls including
several from students wanting more information about what would
be involved. The main issues raised by parents were our reasons
for selection of their child, a wish for fuller details or
reiteration of what would be involved, concerns about the use
of video equipment, or reluctance of the child to take part.
Nine children were replaced as a result of these contacts,
three at the child's request, and six at the parents' request
(two did not want their child video recorded, two were concerned
about their child's capabilities and associated stress and
two gave no reason).
At
the year 4 level we also received about 20 phone calls from
parents. Some wanted details confirmed or explained (notably
about reasons for selection). Four children were replaced at
parents' request because the parents were concerned about additional
stress for their children. One child was replaced because the
parents were Exclusive Brethren and did not want their child
viewing video material. Two children were withdrawn by parents
without an explanation.
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Practical
arrangements with schools
On the basis of preferences expressed by the schools,
we then allocated each school to one of the five assessment weeks
available and gave them contact information for the two teachers
who would come to the school for a week to conduct the assessments.
We also provided information about the assessment schedule and
the space and furniture requirements, offering to pay for hire
of a nearby facility if the school was too crowded to accommodate
the assessment programme.
Results
of the sampling process
As a result of the considerable care taken, and the attractiveness
of the assessment arrangements to schools and children, the attrition
from the initial sample was low. Less than one percent of selected
schools did not participate, and less than two percent of the originally
sampled children had to be replaced for reasons other than their
transfer to another school. The sample can be regarded as very
representative of the population from which it was chosen (all
children in New Zealand schools at the two class levels except
the one to two percent in special schools, Kura Kaupapa schools,
or schools with less than four year 4 or year 8 children).
Of
course, not all the children in the sample were actually able
to be assessed. Twenty year 8 students and 34 year 4 students
either left school at short notice and could not be replaced
or were absent throughout the assessment week. Some were absent
from school for some of their assessment sessions, and a small
percentage of performances were lost because of malfunctions
in the video recording process. For many tasks, over 95 percent
of the sample were assessed. No task had less than 90 percent
of the sample assessed. Given the complexity of the Project,
this is a very acceptable success rate.
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Composition
of the sample
Because of the sampling approach used, regions were fairly represented
in the sample, in approximate proportion to the number of school
children in the regions.
Region |