education longitudinal study of 2002 nsf summer data policy institute july 22, 2007
TRANSCRIPT
Education Longitudinal Study of 2002
NSF Summer Data Policy Institute
July 22, 2007
Objectives of ELS: 2002
Monitor the critical transitions made by a cohort of high school sophomores (10th graders) through college into their adult careers
Maintain comparability with NLS-72, HS&B, and NELS:88 to measure trends in transitions and outcomes over time
Link the assessment of achievement outcomes to other high school assessments (NAEP and PISA) for purposes of analysis
Focus 2nd follow-up on issues of college access and choice
ELS: 2002 Basic Survey Design
Stage 1: School selection Target population: schools with 10th graders Probability of selection proportional to school size
Stratification: region x urbanicity x school control Total strata: 96
Over sampled: Catholic schools, and other private Final sample size: 752 responding schools with a
10th grade Similar to NELS:88 but starts in spring of 10th grade
ELS: 2002 Basic Survey Design
Stage 2: Student selection Random selection of about 26 students per school
From student rosters provided by school Number of students per school was limited to minimize
burden Rosters organized by four race/ethnicity groups
Over-sampled: Asians/Pacific Islanders All ELL and special education students included
(expanded sample) Sample size: 17,591 10th grade students selected
representing 3.6 million students
ELS: 2002 Basic Survey Design
Contextual data sources: One parent per student Two teachers per student
One a mathematics teacher of the student One an English/language arts teacher
Principal of the school School characteristics
School librarian/media center director Planned follow-ups:
First follow-up, high school seniors (2004) (done) Second follow-up, college sophomores (2006) Third follow-up, eight years after high school (2012)
Sample Design and Weights
Schools and students are assigned weights according to their probabilities of selection.
Use of these weights in analyses is necessary to obtain accurate population estimates.
Values of the weights for school and student sample members are inversely proportional to their probabilities of selection.
Sample Design and Weights
School Weights – E.g., Stratum H in the Pacific region contains 80
public, urban, schools If two schools are chosen (H1 and H2), the school
weight for each one is 80/2=40 So each sampled school in stratum H represents 40
schools with a 10th grade.
Sample Design and Weights
Student weights – Roster of all 10th graders enrolled in spring 2004
was provided by the selected school If school H1 had 120 sophomores and 24 were
selected, then the “within school weight” for each student would be 120/24 = 5.
The overall weight for these students would be 40 x 5 = 200.
Sample Design and Weights
Base Year student weights: The result is a Base Year student weight for every
individual in the sample corresponding to the number of individuals in the population that person represents.
The distribution of these weights is:
Statistics Base Year student weight, BYSTUWT
Mean 224
Median 205
Quartiles 99, 205, 300
Range 5-978
Sample Design and Weights
Base Year school weights: For purposes of analyzing schools, there is also a
school weight for the Base Year schools. The distribution of these school weights is:
Statistics Base Year school weight, BYSCHWT
Mean 32.7
Median 17.0
Quartiles 7.4,17.0,27.4
Range 0-395.7
Sample Design and Weights
Between the Base Year and First Follow-up, Some student do not respond, and Some students migrate to new schools
In ELS, the sample weights are adjusted to account for for sample member non-response Using model-based methods The total weight for Base Year cohort does not
change. All students who transferred to another school were
included in the First Follow-up data collection
ELS: 2002 Sample Distribution
Change in the size of the ELS:2002 sample of schools and students, by data collection stage (unweighted)
Base Year First Follow-up
Original school
Total number of schools 752 747
Total number of students 16,202 13,988
Average number students per school 21.5 17.8
Transfer school
Total number of schools --- 1,130
Total number of students --- 1,248
Average number students per school --- 1.2
Source: ELS 2002 data file
Sample Design and Weights
Additional measures to correct for non-response: Non-respondents are included in follow-ups
Receive special questionnaires to obtain data otherwise collected in previous follow-up
Universe variable, F1UNIV1, shows the F1 respondents who were non-respondents
All of the main student background variables (sex, race, SES, etc.) and some status variables are imputed
Sample Design and Weights
After imputation and non-response adjustment, a panel weight, F1PNLWT, is formed from sample members for whom there is response data in both the Base Year and First Follow-up. This panel weight should be used whenever change
in a variable from BY to F1 is analyzed. This panel weight is zero for all students for whom BY-
F1 information is not available The sample of cases still represents the distribution of
the original Base Year Cohort
Sample Design and Weights
For all students who completed a First Follow-up questionnaire, there is also a questionnaire weight, F1QWT F1QWT includes the freshened sample and all other
students in Base Year or Transfer schools who completed a First Follow-up questionnaire, including dropouts, etc.
The cross-sectional sample of seniors is formed by crossing F1QWT with a cohort flag, G12COHRT, identifying all in-school seniors in the First Follow-up.
ELS Analysis Populations (E4P)
Sample Population Weight
Base year students Cross-section of sophomores BYSTUWT
Expanded sample Cross-section of sophomores, including ineligible students
BYEXPWT
(restricted)
First Follow-up Cross-section of seniors (freshened)
F1QWT x
G12COHRT
Longitudinal panel Same group of sophomores followed for 2 years
F1PNLWT
Longitudinal panel Same group of seniors followed for 4 years
F2PNLWT
Base year schools Schools with 10th grade BYSCHWT
Design Effects and Standard Errors
Because of the selection of multiple students per school, the ELS sample is “clustered”
Because of this clustering, the standard errors of population estimates are larger than they would be with simple random sampling (SRS)
The extent of departure is measured by the “Design Effect” or DEFF
Because of the “DEFF,” special software must be used to correctly estimate standard errors
Design Effects and Standard Errors
In general, DEFF is defined as the ratio of, the square of the “correct” standard error by the square of the standard error of the estimate
assuming simple random sampling (SRS).
DEFF = (correct S.E.2 / (SRS S.E.)2
Design Effects and Standard Errors
3.7
2.3
1.9
1.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
NELS:88 ELS:2002
Design effect
Root designeffect
Mean and root design effects for NELS:88 and ELS:2002 sophomore cohort panel estimates
Survey Components
Base Year survey Spring 2002 sophomores Student questionnaire Student cognitive tests
Mathematics Reading
Parent questionnaire Teacher questionnaires Principal questionnaire
(school information) Library/media
questionnaire School facilities checklist Geocoded data available
First Follow-up survey Spring 2004 seniors Student questionnaire
Transfer student quest. Dropout questionnaire Early graduate quest. Home school quest. New student quest.
Student cognitive tests Mathematics
Principal questionnaire (school update)
High school transcripts
ELS Results: Educational Expectations
10
25 296
19
22
0
20
40
60
80
100
1981-82 1991-92 2003-04
19
37 36
13
26 31
1981-82 1991-92 2003-04
33
33
50 53
3631
1981-82 1991-92 2003-04
Bachelor’s degree
Graduate or professional degree
Percentage of 12th graders who expected to attain a bachelor’s degree or a graduate or professional degree: 1981-82, 1991-92, and 2003-04.
16
4451
32
6367 64
86 86
Low SES Middle SES High SES
Survey Components
Second Follow-up Two years after high school Young adult questionnaire
High school completion update College choice College enrollment College major Employment (and military
service) Life course (living situation,
volunteer work, expectations Administrative records
Federal student aid received SAT/ACT scores GEDs received
Third Follow-up Eight years after high school Adult questionnaire
College enrollment College completion status Employment Life course (living situation,
volunteer work, expectations) College transcripts
ELS High School Transcripts
Sample: Collected from Base Year school, and If in another school, from last school of attendance
Provides a complete record of high school coursework Course titles, grades earned, credits earned, year
taken, grades 9-12 Coded according to course classification schemes
Includes updated high school completion status Diploma or certificate of attendance GED Still in school
ELS High School Transcripts
Ninth and eventual 12th grade mathematics course completed : 2004
Percent completing specific course by end of high school
Among students who complete geometry in the ninth grade, 84% take Advanced mathematics (trigonometry-pre-calculus or calculus) by the 12th grade
Among students who take general or applied mathematics in the ninth grade, 10% take Advanced mathematics
Trend analysis with ELS, NELS, HS&B
Survey and follow-upHigh school sophomores
High school seniors
College sophomores
College Graduates
ELS: 2002/12 3rd FU 2012
ELS: 2002/06 2nd FU 2006
ELS: 2002/04 1st FU 2004
ELS: 2002 BY 2002
NELS: 88/2000 4th FU 2000
NELS: 88/2000 3rd FU 1994
NELS: 88/2000 2nd FU 1992
NELS: 88/90 1st FU 1990
HS&B: 1980 Soph. 4th FU 1992
HS&B: 1980 Soph. 2nd FU 1984
HS&B: 1980 Soph. 1st FU 1982
HS&B: 1980 Soph. BY 1980
CT
CT
HT
HT
HT
CT
Availability of Restricted Data
Restricted data files Use requires a licensing agreement with NCES “Restricted” files contain information not on the “Public
Use” data files Linking variables Course records from student transcripts No top or bottom coding
Released on CD-Roms with the same ECB and kinds of documentation as Public Use files.
http://nces.ed.gov/pubsearch/licenses.asp
Education Longitudinal Study: 2002
For additional information:
Go to ELS: 2002 web site on the NCES web site:
nces.ed.gov/surveys/els2002
To obtain Public Use data files:
click on “Order CDs” at the URL above
Sign up for the “High school longitudinal studies” News Flash on the NCES web site