High School Experience: Comparing Self-Report and Transcript Data from the NLSY97 A. Rupa Datta Parvati Krishnamurty NORC at the University of Chicago NLSY97 May 2008 Anniversary Conference (draft 5/24/08) 10th 1 Introduction The National Longitudinal Survey of Youth, 1997 Cohort (NLSY97) dataset include two sources of information about respondents’ high school experiences: selfreports from annual interviews with individuals throughout their high school years, and abstracted information from their high school transcripts. Although the transcripts and interview data were designed to complement one another, their co-existence offers the opportunity to compare interview and transcript data as alternative sources for some key pieces of data about educational experience. In this paper, we describe the two types of data collected from these sources and assess the concordance of some measures. We conclude with some comments about the relative merits and weaknesses of each type of data for measuring different aspects of high school experience. The NLSY97 high school transcript data differ from other high school transcript data sets in a number of ways. Perhaps most relevant is that the NLSY97 (together with the NLSY79) may be the only American high school transcript data set that does not stem from a school-based sample. Although there are other, larger transcript data sets available (for example, NELS:88, ELS, Add Health, NEAP), all of these stem from an originally school-based sample design. In contrast, the NLSY97 respondents derive from an areaprobability sample. As a result, there are on average fewer than three respondents per high school in the NLSY97 data. Another distinctive feature of the NLSY97 transcript data is that all youths who attended high school were included in the study. Many other transcript data sets include only high school graduates. Including non-graduates complicates the structure of the 2 dataset and analyses of the data, but obviously lends richness and supports a host of research questions that are not relevant to a dataset of graduates only. Also, the NLSY97 schooling experience data are collected in an intervieweradministered format, whereas most major educational studies have collected data in selfadministered form, especially in the early school-based waves. The literature on mode effects generally finds that self-administration matters more in sensitive items. In the mode effects literature, sensitive items are often identified as delinquency, income, or sexual behavior. It’s unclear whether or not some dimensions of high-school experience may also behave as sensitive items. If so, we would trade off the ability of interviewers to establish rapport and assist respondents in recall and response construction (thus improving the quality of self-report data) against social desirability bias which would diminish the accuracy of self-reports. Finally, the NLSY97 is the only large high school transcript data set that has such a wealth of interview data in conjunction with the transcript data. The various Department of Education data sets (NEAP, ELS, NELS:88, etc.) as well as AddHealth, all involve infrequent longitudinal interviews at best (the NEAP is cross-sectional). In contrast, the NLSY97 respondents were interviewed annually throughout high school and so provide a wealth of interview data that can be considered in tandem with the transcript data. Although there are some published studies comparing self-reports with transcript data on educational experience, these distinctive features of the NLSY97 transcript provide some motivation for looking to these data to extend the previous body of work on the relative merits of transcripts and self-reports. 3 Kane, Rouse and Staiger (1999) did compare transcript and self-report data on post-secondary enrollment in order to improve estimates of the returns to schooling. Using data from the National Longitudinal Survey of the Class of 1972 as well as the National Educational Longitudinal Study: High School Class of 1988, they estimated that in binary categorizations (such as graduation from 4-year college), self-report data could suffer less reporting error than transcript data. They estimated also that reporting of years of schooling among non-graduates from college and among high school dropouts could be quite inaccurate in both transcripts and self-reports. Naifeh and Shakrani (1996) compared self-reports and transcript data among high school graduates who had participated in the 12th grade mathematics NEAP in 1990. They found that concordance rates were low (fewer than 50% exact matches) in reports of individual math courses taken, numbers of courses taken, highest math course taken, and combinations of courses taken. Among discordant cases, however, the vast majority differed by very small magnitudes, typically just one course difference out of eleven courses tallied. Although there was some tendency for interview data to over-report relative to transcript data, there were instances of the opposite, including times when an individual student under-reported some course enrollment and over-reported others relative to the transcript data.1 The authors found that transcript data exhibited somewhat better behavior in association with NEAP math achievement test scores, for example, transcript data but not self-reports were monotonic in percent proficient against number of math courses. In general, both self-reports and transcript data were associated in similar (and expected) ways with the NEAP math scores. 1 This might indicate mis-classification of students into the categories of math courses asked about. 4 Kuncel, Crede and Thomas (2005) provide a review of the previously published literature comparing transcript and self-report data, including a meta-analysis of results on the accuracy of grades, class ranks, and test scores. They find consistent evidence that students with more success in school (i.e., higher grades, lower class rank, etc.) report more accurately. They also find evidence that recall bias results in deterioration of accuracy as the elapsed time from school enrollment increases. Many of these studies use data that were collected administratively rather than in a research context. Students self-reporting grades or class-rank as part of standardized test administration (like the ACT) or as part of an admissions application may be acutely aware of negative consequences for mis-reporting, or the likelihood that consumers of their data may also have access to their high school transcripts for comparison purpose. This threat of corroboration may induce more accurate reporting than in the no-consequences context of a survey interview. The reviewed studies clearly take the position that transcript data represent ‘truth’ and deviation from them in self-reports is indication of inaccurate selfreport data. Zimmerman, Caldwell, and Bernat (2002) take a different approach to the transcript/self-report comparison, suggesting that the size and direction of the discrepancy between the two measures of grade-point average (GPA) may itself be indicative of a youth’s psychological state, academic beliefs, and problem behaviors. In their case, they find that self-reports and discrepancies are more predictive of problem behaviors than are transcript measures of GPA. Background: NLSY97 and NLSY97 Transcript Data 5 The NLSY97 sample consists of 8,984 American youths who were born 1980 to 1984 and living in a U.S. household in 1997. The nationally representative sample includes oversamples of African-American and Hispanic youths. The approximately 9,000 NLSY97 individuals have been sought for interviews annually since then. Interviews are approximately one hour in duration and most often conducted in person with a substantial subset of items administered using Audio Self-Administered technology to provide greater privacy for collection of sensitive items. Data are collected on a wide range of topical domains, including schooling, employment, family formation, delinquency, income and assets, and health. Data in key substantive areas are collected in event history format. Respondents are solicited for each interview regardless of their participation status in prior interviews. In the ninth round of data collection in 2005, 81.7 percent of the original sample completed an interview. Because many respondents complete interviews after spells of attrition, 91 percent of the original sample have now provided information about their lives through 2005. High school transcript data were collected in 2000 and 2004 concurrent with main interview data collection in those years. In 2000, high school transcripts were sought for 1622 youths who had 1) previously reported graduating from high school or who had dropped out of high school and were at least 18 years old, 2) an identifiable high school reported in interview data, and 3) provided signed permission for NORC to seek access to their school records. Through unrelated circumstances, several hundred signed waivers were destroyed, and transcripts could be sought only for those respondents who provided permission on a newly signed waiver. Transcripts were obtained for 1417 respondents. 6 In 2004, transcripts were sought for 5701 youths whose transcripts were not received in the initial wave of transcript collection. Wave 2 data was obtained for 4815 respondents. A total of 6,232 transcripts were received and coded for youths across the two waves of transcript collection. These 6,232 largely comprise the sample for this analysis. Most of the NLSY97 respondents had completed their high school career by 2004, so we have complete high school transcripts for them. The data collection was done by mailing a transcript request packet to each school from which a respondent received his or her high school diploma or the last school the respondent reported attending during a NLSY97 interview. The packet included a cover letter addressed to the principal, a one page cover-sheet questionnaire collecting school specific grading and transcript policies, a student request list listing the sampled students in the school and the signed permission forms for these students. Transcript, course catalog and information on special programs were provided by the school. Transcript data could not be obtained for 2752 youths. Most of the nonrespondents did not sign a permission form or did not have a school identified for mailing out the transcript requests. In some cases, the school record was not found or the school or school district refused to release the information. Table 1 shows the number of NLSY97 respondents for whom transcripts were obtained, those who were not interviewed and the reasons for non-response. Table 1: Transcript survey status Category Collected transcripts Sub-category Total 6232 % of Sample 69.4% 7 Wave 1 Wave 2 Wave 2 fielded, not collected Refusal at district level Refusal at School level Student record not found Student record not available 1417 4815 886 111 231 427 117 1866 Not fielded for transcript survey Permission not secured School not identified Not mailed, final blocked Total 9.9% 20.8% 1572 231 63 8984 100% Structure of the NLSY97 schooling data In the schooling section of the NLSY97 Youth Interview, respondents were asked about their current or most recent school in round 1. From round 2 onwards, data was collected in a retrospective format so respondents were asked about all the schools they attended since the last interview. The data is organized so that enrollment dates and institutions are identified, enrollment spells are rostered and then information about each enrollment spell is captured. Self reported data on the respondent’s high school experience include: Schooling attainment (highest grade completed and highest degree received) Course of study (college prep, vocational, technical) 8 Types of math, science and other courses taken Overall grades they received (8th grade, end of high school) Highest SAT math, verbal or ACT composite score Number of schools attended Type of school attended Additionally there is data on school based learning programs, grade progression, enrollment status and school characteristics. Structure of the NLSY97 transcript data The NLSY97 high school transcript data consists of a set of student-level variables, information from the school which sent the transcripts, term-specific and course-specific information. The school from which the high school transcript was collected is referred to as the primary school in the data. Transcripts often include information on courses taken at transfer schools and summer programs. The transcript data include the following: Information on the primary school: school sector, number of students in the district, percentage of districts students in grades 9-12, coursework offered (e.g. Calculus, AP, IB, vocational education) Term-specific information for up to 18 terms including dates, type of school year, academic year, grade level, number of credits Course specific variables including course codes (SST-R), grade and credit value of the course. Course grades are converted into standard grades. Carnegie credits for each academic year 9 Cumulative percentage of New Basics curriculum requirements completed by academic year Grade point average, school’s report as well as Carnegie credit weighted GPA overall and by academic year Test scores for SAT, ACT, SAT-II, PSAT and AP tests. Number of days absent from school or tardy School completion status Enrollment dates Participation in special, gifted or bilingual programs. Specialization variables (academic/vocational specialist or concentrator) Pipeline variables to measure progression in math, foreign language and science Comparing NLSY97 Self-report and Transcript Data The NLSY97 youth interview and high school transcript data were designed for different purposes and with different constraints. Thus, although they both describe high school experience, they are not intended to provide identical measures of the same constructs. Rather, each provides some information about the respondent’s high school experience. As with other sections of the NLSY97 youth interview, the section on high school experience was designed with several principles in mind. The data are collected in month-level event-history format, and great emphasis is placed on asking questions that respondents can reasonably answer, formulated in ways that are cognitively reasonable. (An alternative would be to ask what researchers might most want to know – cumulative 10 GPA to the third decimal place, for example – whether or not respondents can know and report such information accurately.) Some of the design of the NLSY97 schooling data was informed by experiences with the NLSY79 and other earlier data sets. In these, students were often observed with inexplicable regression or jumps in grade of enrollment. It was also difficult to differentiate among non-graduates, for example, those completing all but one term and almost all requirements versus those who had never completed a full year’s worth of courses. With these issues in mind, great emphasis was placed on collecting data to support very nuanced data on students’ progression throughout high school. Enrollment status and grades of enrollment are collected for every month so that researchers can identify and understand regression and jumps in grade level. Progression is addressed in other ways also, including expected graduation date and point-in-time status reports supplementing the event history reports. All gaps in enrollment are also collected. The emphasis on grade progression and month-by-month enrollment status comes instead of greater detail on high school activities – for example, courses taken, disciplinary actions, counseling or other services received, extra curricular activities. Because accurate enrollment status was a principal objective of the NLSY97 in the early years of data collection, the fielding period was restricted to overlap with the traditional 10-month American school year. This timing has the advantage of ensuring that a maximum number of respondents are indeed enrolled at the time of interview. On the other hand, it implies that the reference period for the interview – from the prior interview to the current one – will typically span two school years, neither in its entirety. This framework does not suit asking questions about completed grades, or about course 11 enrollments, since recall periods can be long and salience may be low (much to the dismay of high school teachers). The abstraction of data from high school transcripts is also constrained in many ways. The transcripts tend to have more information on the grades from the primary school. Information on grades, courses and grading scales from transfer schools or summer schools may be sketchy. The school may lack complete information on respondent’s test scores and school attendance as well. The sample for the main survey and the Transcript survey are compared in Table 2 to see if there were any major differences in demographic variables, background variables or aptitude test scores between the two samples. Table 2: Comparison of the NLSY97 sample and the Transcript sample Percentage of respondents in each category (Weighted) Demographic variable Sex Birth year Race-ethnicity Region Mother’s Value Male Female 1980 1981 1982 1983 1984 Black Hispanic Mixed NHNB Northeast North Central South West Less than high NLSY97 sample (8984 respondents) 51.32 48.68 20.09 19.94 20.27 19.44 20.26 15.42 12.86 1.22 70.51 18.6 26.22 34.29 20.89 23.91 Transcript survey (6232 respondents) 50.62 49.38 22.52 21.22 19.42 17.72 19.12 15.1 11.91 1.06 71.93 18.34 27.77 32.95 20.93 21.62 12 education PIAT Math score (quartiles) ASVAB scores (quartiles) school grad High school grad More than high school Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 34.32 41.77 34.59 43.79 59.16 16.42 14.29 10.13 39.26 20.03 20.18 20.53 59.61 15.77 14.21 10.41 34.26 20.68 22.15 22.91 Transcript survey respondents have slightly higher ASVAB scores, larger percentage of mothers who are educated beyond high school (and fewer mothers who are high school dropouts), There are also slight differences in the transcript and main sample by region. For instance, the transcript survey respondents have a slightly higher percentage of NHNB (white), older and female respondents compared to the main survey. The differences are minor and most are in the 1-2% range. Comparing self-report and transcript measures: There are a wide variety of measures on which data are available from the transcripts as well as interviews. Reasons for discrepancies between the two sources can be categorized as differences in the designs of the data, response errors in respondents’ reports, administrative errors or other differences in interpretation/procedure in school records, or differences in time periods for which the measures apply. Differences in design of the data include differences in concepts, wording and time frame of the questions in the two surveys. Response errors made by respondents include social desirability bias, cognitive difficulties with answering questions, recall and recency effects. Administrative errors due to lack of information or differences in procedures 13 could have occurred in the transcript survey. One indication of this is that there was high item non-response for certain questions in the survey. The two surveys were timed very differently and therefore could be measuring slightly different things. Respondents were asked about schooling at different points while the high school transcript was collected at the end of high school. In this paper, we compare some important schooling measures like high school graduation, grade point average, number of schools attended, math courses taken and standardized test scores. 1. High school graduation One item that both data sources can capture is whether or not the youth graduated from high school. Table 3 below shows that in approximately 93 percent of cases where both self-report and transcript data are available, the two sources are in concordance on graduation status: Table 3: A comparison of high school graduation status from self reports and transcripts Self Report Transcript No HS HS Diploma Diploma 1049 117 No HS Diploma HS Diploma 314 4574 Total cases with both self-report and transcript graduation status: 6054 The transcript variable shown here is coded from an item that asked school administrators to provide the reason that a student ceased enrollment at a school (other options included dropped out, expelled, transferred to another school, unknown, etc.) The self-report variable asks youths directly whether or not they have received a high school diploma. 14 Of the 117 youths whose transcripts indicate graduation, but self-report indicates nongraduate, 52 youths had not been interviewed since their transcript-reported graduation dates, so there is not necessarily a contradiction between the two sources. Of those who had been interviewed since their transcript-reported graduation date, none of the remaining youths report a highest grade completed higher than 11, although the majority had some 12th grade coursework on their transcripts. There are 314 youths who self-report graduation but whose primary transcript survey school did not indicate graduation. Of these, 156 youths report a graduation date that comes after the departure date given by the school. There is no logical contradiction in these cases. Fifty youths self-report a graduation date that is the same as the departure date from school given in the transcript records. Their transcripts showed the following reasons for departure: transferred 9 youths), dropped out (20), GED (14), withdrew (5), discharged (age greater than 18) (2). These all suggest contradiction between transcripts and self-reports. Thirty-eight youths self-report a departure date that precedes the schoolprovided departure date. These could be contradictions or they could be cases in which the youth had completed in one school, but transcript school was not aware of the transfer. Seventy youths had missing date information that leaves ambiguous whether or not a true contradiction exists. It is worth noting that the transcript variable in this case was recorded in a questionnaire that school administrators were asked to complete as a supplement to the transcript itself. As such, the transcript errors could include simple transcription errors, school staff who relied on their own recollections rather than referencing documentation, or other non-systematic reasons for poor data quality. 15 Overall, it appears that approximately half of the discordant cases have genuinely contradictory information across the two sources. The evidence does not favor either the self-reports or the transcript data as the superior data source in determining high school graduation status. 2. GPA Respondents reported their grades in high school as mostly A’s, half As half Bs and so on. We excluded those who reported mixed As through Cs, mixed grades and those who report that their high school was ungraded, since it was difficult to classify these into a four point scale to make it comparable to the transcript grades. These were reclassified into a scale of 0 to 4. There were various transcript variables that provided the GPA. We used the transcript survey created variable that calculates Carnegie-credit weighted GPA on a four point scale. These were recoded to scale of 0 to 4. Table 4 shows a comparison of the high school GPA variable from the self reports and transcripts. Table 4: Comparison of high school GPA from self reports and transcripts Transcript GPA Self reported GPA 0: Mostly below Ds 1: Half Cs and Ds or mostly Ds 2: Half Bs and Cs or mostly Cs 3: Half As and Bs or mostly Bs 0 1 2 3 4 Below 1.0 1.0 to 1.9 2.0 to 2.9 3.0 to 3.8 3.8 and above 3 22 20 3 0 9 153 261 26 1 15 3 1617 260 1 4 58 897 1361 11 16 4:Mostly As Total: 5753 0 5 40 500 227 High school GPA categories for respondents match in about 58.4% of cases. In many cases, the transcript GPA seems to be higher than self reported for lower grades (C and D’s and below) and lower than self reports for higher GPAs (As and B’s). There could be several reasons why the self reports do not match the transcript reports for the GPA variable. There were some differences in design. In the transcript survey, the GPA is weighted using Carnegie credits while the self report is from a question that asks for the respondent’s impression of their overall grades in high school. Thus the two reports are measuring different concepts. There is also the possibility of response errors. Since the question about high school grades is not very specific, and respondents may give their overall impression of their grades in high school. This makes their response subject to various errors including recall errors and recency effects. For instance, respondents may not be able to correctly recall their grades in the early years of high school and may base their response on the most recent year of high school. Respondents are also likely to report better grades than they actually received because of social desirability effects. There may be various administrative and classification issues that affect the transcript reports. Calculations in the transcript which were made based on grades from transfer/summer schools may be subject to errors, since the information may not be complete and all the grades may not be known by the primary school. This could be a particular problem for cases where the schools reported different types of grades and did not provide grading specifications. Differences in how grades are classified may also 17 contribute to the differences we observe between the self and transcript data. The respondent’s reports are based on their specific school’s grades while the transcript variable is standardized and weighted. 3.Number of schools attended Comparing the number of schools attended can provide a crude measure of the concordance between the two data sources. In addition, the number of schools can be of substantive interest in understanding disruptions to schooling, and the level of transiency experienced. Table 5 below shows the number of schools reported by youths in their interviews, compared with the number of schools identified on the youth’s high school transcript. During each NLSY97 interview, youths are asked to report every ‘regular’ school they have attended since the prior interview period. An over-time roster permits identification of schools the youth has previously attended, so that transitions can be accurately measured. For this variable, we have identified unique schools that a youth reported attending and that the youth classified as a high school (as opposed to a 2 year college, a middle school, or other schooling levels). On the transcript side, each distinct school appearing in the record is counted. Table 5 : Comparison of number of schools reported in self reports and transcripts 0 Self Report 0 1 2 3 4 or more 1 69 3735 580 131 29 Transcript 2 3 730 396 90 34 3 0 131 98 57 19 4 or more 0 42 54 20 14 18 Total number of cases with self-report and transcript numbers of schools attended: 6232 Sixty-seven percent of youths had exact matches on the number of schools attended during grades 9-12. An additional 25.4 percent were discrepant by one school, with more self-reported school numbers exceeding transcript numbers than vice versa (897 vs. 670). Since only youths with a received transcript are included in this analysis, transcript data must show at least one school. On the other hand, self-report data may inaccurately report a school as a middle school only when in fact the youth began enrollment at a middle school, but then continued in its high school program without reclassifying the school. In addition, students may have attended 9th grade in a middle school. Since transcript data are recorded for the full ninth through twelfth grades, some middle schools will appear in the transcript counts but not in the self-report counts. Conversely, transcript data may differ on their treatment of dual enrollment. In the event that a student was primarily enrolled in a comprehensive high school but also took courses at a local vocational school that had linkages to the first school, the interview data would likely count only the comprehensive school. There may be some differences in how school transcripts handled such a situation. Also, the definition of ‘regular’ school in the questionnaire reads, “REGULAR SCHOOL IS ONE THAT OFFERS AN ACADEMIC DIPLOMA OR DEGREE; E.G., ELEMENTARY SCHOOL, HIGH SCHOOL, COLLEGE, GRADUATE SCHOOL, LAW SCHOOL, OR NURSING PROGRAM LEADING TO AN RN DEGREE. NOT INCLUDED AS REGULAR SCHOOL ARE: TRAINING AT A TECHNICAL INSTITUTE, LICENSE TRADE PROGRAMS, ETC. UNLESS THE CREDITS OBTAINED ARE TRANSFERRABLE TO A REGULAR SCHOOL AND COULD COUNT TOWARD AN ACADEMIC DIPLOMA OR DEGREE.” It appears that a large number of youths had enrollments during the summer that appear on their transcripts but that the youths did not mention during their interviews. Although credits, course codes, and quality grades typically appear in the transcripts for all prior high schools where the youth earned credit, there is often no 19 additional information about the prior schools. For that reason, it’s relatively difficult to examine the transcript schools to ascertain whether or not they are valid institutions. We have two indications of whether or not all reported schools are in fact valid places of enrollment for the students. Out of 8,984 students, there were 427 cases in which the student record was not found. These are instances in which the schools were unable to identify a student in their records who had attended their school. In large part, these were matching problems – variations in spelling, birthdates not matching closely enough, etc. In some cases, schools had misplaced some subset of their previous student records, especially when a school had closed within a district. Some of the remaining cases in this disposition would be instances in which the youth reported attending a school that he or she had indeed never attended. An additional problem indicator is the 231 youths who had self-reported enrollment, but whose last school could not be identified. These are cases in which the school name or address could not be linked to a currently or previously existing institution. The 7.3 percent of the sample falling into one of these two categories probably offers a ceiling on the rate of students falsely reporting enrollment in schools. For this measure, it would appear that neither self-reports nor transcripts dominate, and in fact some combination may provide the most accurate information. 4.Math courses taken We compared the math courses reported by the respondent to those reported in the transcript to see if the math course progression was similar in the self reports and transcript reports. 20 Respondents reported the math courses/categories they took in every round and we used this information to calculate the highest level of math courses they took between 1997 and 2003. These were coded as shown below for 1998-2003, so the 1997 reports were reclassified to conform to the same code frame which is shown below. 0 1 2 3 4 5 6 7 8 9 None General/basic/vocational math Algebra.I Geometry Algebra II Trigonometry Precalculus/Adv. Algebra Calculus Other advanced math Other math class Note that the category 9 “Other math class” is problematic since it is unclear what math courses are included. Therefore, we did the analysis both including and excluding that category. In the transcript survey, pipeline variables were created to indicate the highest level of math courses taken by the respondent based on course information in their transcripts. These are based on NCES standards with some minor modifications to account for the R-SST course coding scheme that was used. The pipeline variables for progress in Math are coded as follows: 100 No math 200 Non academic: highest course is General/consumer or occupational math 300 Low academic: highest course is Pre-algebra2* 400 Middle academic 1: highest course is Algebra I ,Geometry or Unified math (2 or fewer yrs) 500 Middle academic 2: one or fewer Carnegie credits in Algebra II to pre-calculus or 3 years of unified math 600 Advanced academic 1: more than 1 credit in Algebra II through Pre-calculus, Trigonometry, Advanced Math 2 There is no corresponding category for this in self reports. 21 700 Advanced academic 2: highest course is Other Advanced Math 800 Advanced academic 3: highest course is Advanced math—Calculus, IB or AP math Table 6 compares the math courses reported by the respondent to the transcript variable. When no math courses were reported, the math pipeline variable does not correspond well with the respondent reports. There are respondents who reported taking math courses even though the transcript reported that they didn’t and vice versa. In other categories there isn’t always a clear correspondence between categories in the transcript variable and the self reports. For instance, low academic (300) does not have an equivalent category in the self reports. There are fairly large numbers in all cells for a self report of 9 (other math courses), probably because this category is a little ambiguous. We find that the non-academic category from the pipeline variable corresponds to the self report of basic/ vocational or algebra I and low academic to algebra I. Middle academic I corresponds to algebra I, geometry and algebra II and Middle academic II to algebra II, though some report their highest math course as geometry, trigonometry or pre-calculus. Advanced math I corresponds to pre-calculus with some respondents reporting algebra II and trigonometry as the highest math course. For advanced math II we see many respondents reporting algebra II, pre-calculus or other advanced math as the highest course they took. For advanced math III, most of the respondents report their highest course as calculus while some report taking other advanced math classes. Some of the spread we see in middle academic categories could be due to other criteria being 22 used in the construction of the pipeline variables like including the number of years of unified math courses and the number of course credits. Transcript report 100 200 300 400 500 600 700 800 0 Table 6: Comparison of math courses taken Self-reports 1 2 3 4 5 6 7 8 9 2 27 12 9 2 0 0 0 7 103 21 34 6 1 2 0 6 126 56 413 305 158 75 71 8 88 55 385 51 7 4 3 6 27 17 363 130 10 5 0 8 63 25 371 877 114 52 2 1 11 3 54 150 177 30 9 2 13 3 52 156 479 57 47 2 17 2 22 23 41 17 348 2 16 8 49 72 108 53 97 Total: 6227 In Table 7, we ignored other math courses while calculating the highest course taken. While there are some differences, the patterns are similar to those in Table 6. Table 7: Comparison of math courses taken, (excluding the “any other math” category while calculating the highest level of math course taken) Transcript report 100 200 300 400 500 600 700 800 0 1 Self-reports 2 3 3 33 15 21 6 1 0 0 9 142 31 49 10 1 3 0 8 122 80 509 80 10 7 3 6 42 20 482 163 12 11 0 4 5 6 7 8 10 78 34 456 1037 154 79 6 1 17 3 64 176 195 42 13 2 16 4 65 181 538 68 56 2 18 4 27 29 48 19 380 3 21 11 78 91 136 66 119 Total: 6225 There could be several reasons for the differences we observe between the transcript and self reports of math coursework. There are some key differences in the 23 design of the questions, especially in the categories of math courses. The categories in the self reports and transcript reports do not correspond well and in many cases the mapping between the categories is not clear. In some cases there is no comparable category (e.g. low academic/pre-algebra), some categories of courses are not well-defined (e.g. other math courses) and the pipeline variables in the transcript are classified based on additional criteria that do not apply to respondent reports (e.g. number of credits, number of years of courses). Respondents may also have been reporting courses they did not complete or did not pass. Various response errors could have occurred in the self reports. Respondents may have problems recalling the math courses they took (especially if they missed rounds) or not be able to correctly identify or classify their math courses into categories. Differences in timing could also be a factor. Respondents reported the level of math courses they took between 1997 and 2003 while the transcript reports are from 1999 or 2003-04 4. Standardized test scores We compared self reported highest scores for SAT Math, SAT Verbal and ACT composite scores with transcript reports of the most recent score. These were the only test scores that were available from both sources. Respondents reported their scores in ranges. We used the created variable for the highest score (created in 2005) but did not include scores reported after 2003 when the second wave of transcripts were collected. From the transcript survey data, we obtained the exact scores from the last administration of the test. We converted these into categories to correspond with the self-reported scores. 24 When we compare the self reports and transcript reports we find that while a large proportion of reports do match, there are a sizeable number of cases with transcript scores lower than self reported scores. These comparisons are shown below in Tables 8 through 10. For SAT math, the score categories match in 63.6% of cases as shown in Table 8. About 62% of the score categories match for SAT verbal scores (Table 9). The self and transcript reports of the ACT composite scores match in about 81% of the cases (see Table 10). For SAT scores over 400, there are large numbers of respondents who reported higher scores than the scores from their transcripts. This is also true for higher scores for the ACT composite. Self reported scores could be higher because respondents were asked to report their highest score while the transcripts reported the respondent’s most recent score. Table 8: Comparison of SAT Math scores from self reports and transcripts Self reported scores 200-300 301-400 401-500 501-600 601-700 701-800 200-300 Transcript scores 301-400 401-500 501-600 6 6 5 3 9 55 18 1 6 78 228 21 4 20 129 267 3 4 11 60 3 7 15 14 Total number of scores available from both sources: 1228 601-700 701-800 0 0 0 9 170 18 0 0 0 0 3 55 Table 9: Comparison of SAT Verbal scores from self reports and transcripts Self reported scores 200-300 301-400 401-500 501-600 601-700 701-800 200-300 6 8 7 7 1 3 Transcript scores 301-400 401-500 501-600 601-700 6 1 1 0 55 21 1 0 76 214 23 2 16 135 296 9 7 23 80 142 0 10 8 19 Total number of scores available from both sources: 1224 701-800 0 0 0 0 3 44 25 Table 10: Comparison of ACT composite scores from self reports and transcripts Self reported scores 0-6 0-6 7-12 Transcript scores 13-18 19-24 25-30 31-36 0 0 0 0 0 0 7-12 0 3 3 1 0 0 13-18 0 11 217 11 1 0 19-24 0 3 98 429 6 1 25-30 0 0 7 59 220 1 31-36 0 0 0 6 10 50 Total number of scores available from both sources: 1137 Some of the differences we see between self reports and transcript reports of test scores could be due to differences in design and various response errors. There were conceptual and wording differences in question wording and concepts between the interview question and the transcript. In particular, respondents reported their highest score, while transcript reports contain the most recent score as of the transcript survey date. Response errors that may have occurred include social desirability effects, difficulties with classification of scores and recall errors. Respondents may have overstated their test scores to the interviewer due to social desirability effects. Both the conceptual difference in the question and the social desirability effect could make the self reported test score higher than the transcript report. Respondents reported their scores in ranges while the transcripts recorded the actual scores. Respondents may have made errors while classifying their scores into ranges. They could also have had problems with recall of their actual test score, particularly if they missed rounds of the survey. 26 5. Characteristics of Respondents with Concordant/Discordant Reports In Table 11 below, we examine four of our selected outcomes to see the extent to which concordance of self-report and transcript measures may be related to other characteristics. The table includes such basic demographic characteristics as gender, race, ethnicity, and region of residence at age 21. Previous literature has found fairly consistently that students of greater academic achievement are more likely to have selfreports that match transcript reports than are students of lower academic achievement. Toward this end, we consider three measures that are likely to be related to a youth’s academic achievement: the educational attainment of the youth’s mother, the youth’s Armed Services Vocational Aptitude Battery (ASVAB) percentile score (if available), and the youth’s self-reported highest grade completed as of age 21. Across the four measures, high school graduation, grade-point average, number of high schools attended, and standardized test scores, the last looks most different from the others in terms of its demographic characteristics. For example, many fewer students with self-report and transcript test scores available are male, Hispanic, have mothers with less than a high school diploma, or ASVAB scores in the lowest quartile. Similarly, students with college-educated mothers or ASVAB scores in the highest quartile are over-represented in this measure. This is presumably simply due to the fact that the ACT and SAT tests are generally only taken by students who are considering 4-year colleges, not a representative group of American high school students. Curiously, the GPA measure seems to exhibit the smallest differences between concordant and discordant cases, although it may be the most subject to social desirability bias. These results may simply be reinforcing the generally poor quality of GPA 27 Table 11: Weighted Demographic Characteristics by Match Status of Key Variables (shown only for youths with both self-report and transcript measures available) HS Graduation GPA School Number Test Scores All Match No Match No Match No All At (n=6232) (n=5617) Match (n=3374) Match (n=4194) Match Match Least (n=431) (n=2392) (n=2038) (n=1229) One NonMatch (n=865) Male Hispanic Black White Mother’s Education: > 12 years Mother’s Education: =12 years Mother’s Education: < 12 years NEast (at age 21) NCentral (at age 21) South (at age 21) West (at age 21) ASVAB missing ASVAB <= 25% ASVAB 25-75% ASVAB > 75% Highest Grade Completed at age 21 0.51 0.12 0.15 0.73 0.44 0.51 0.11 0.14 0.74 0.45 0.50 0.16 0.22 0.62 0.35 0.51 0.12 0.14 0.74 0.46 0.50 0.12 0.15 0.73 0.42 0.51 0.10 0.14 0.75 0.45 0.50 0.15 0.17 0.68 0.41 0.43 0.04 0.08 0.87 0.62 0.48 0.09 0.12 0.79 0.57 0.35 0.34 0.35 0.35 0.34 0.35 0.33 0.28 0.29 0.22 0.21 0.29 0.19 0.24 0.20 0.26 0.10 0.13 0.14 0.15 0.08 0.13 0.16 0.16 0.11 0.14 0.23 0.23 0.23 0.18 0.23 0.24 0.24 0.20 0.33 0.17 0.29 0.29 0.23 0.30 0.28 0.26 0.33 0.26 0.32 0.17 0.18 0.16 0.19 0.16 0.16 0.20 0.14 0.14 0.17 0.16 0.21 0.16 0.17 0.16 0.18 0.11 0.14 0.34 0.33 0.48 0.32 0.35 0.32 0.39 0.14 0.20 0.49 0.43 0.41 0.44 0.42 0.44 0.41 0.39 0.47 0.23 0.24 0.11 0.24 0.23 0.24 0.20 0.46 0.34 12.9 12.96 12.47 13.1 12.77 13.06 12.54 14.16 13.96 28 measures, especially given significant variability across schools, and the vague nature of the self-report item. Hispanic youths are generally over-represented among discordant cases, as are Black youths, although less so. The patterns for the four Census regions are inconsistent across the four measures. Among the measures related to academic achievement, in all four measures, youths with concordant reports have higher average value of highest grade completed at age 21 than do youths with discordant reports. Youths with college-educated mothers are over-represented among concordant reports, while youths with mothers who did not complete high school are over-represented among discordant reports. These results are generally consistent with previously documented patterns from other data sets. Youths with ASVAB scores in the lowest quartile are over-represented among discordant reports, and those with scores in the highest quartile are over-represented. This is most true for high school graduation status, and least true for grade-point average. Alexander, Entwistle, and Bedinger (1994) have suggested previously that among fourth graders and their parents, cognitive ability to understand and recall grades received in school may contribute to discrepancies in accuracy. The cross-tabulations of ASVAB score with concordance status are consistent with this hypothesis. Sample Regressions Using Self-Report and Transcript Measures A key issue in evaluating the relative merits of the NLSY97 self-report and transcript data on high school experience is the extent to which the two generate substantively disparate results when used in analyses. If the discordances are essentially 29 random, then they may be of little worry to researchers. If the two different sources of data generate substantially different analytic results, then it may be crucially important to try to reconcile or to determine which is the ‘true’ value. In Tables 12 and 13, we provide example regressions of three outcomes: no post secondary schooling by age 21, highest grade completed by age 21, and annual weeks worked in year of 21st birthday. The purpose is not so much to estimate the contribution of the self-report or transcript measures in determining these outcomes. Rather, our intent is to see the extent to which results differ by our choice of measure. Table 11 shows each post-secondary schooling outcome modeled using selfreport or transcript measures of high school graduation status and number of high schools attended. The patterns are similar for all four pairs of regressions. The coefficients on the self-report/transcript measures are quite different from one another, just as the measures themselves can be. Yet, the remainder of the estimated model is quite similar. Aside from race and ethnicity, all other variables yield similar results in both the selfreport and transcript regression, including whether or not the variable is significant, and the approximate magnitude and direction of the coefficient. There may be a slight tendency for the self-report measure to actually make a greater contribution to each outcome than does the corresponding transcript measure. Table 12 shows a pair of regressions using the self-report and transcript measures on high-school graduation status to predict annual weeks worked at age 21. Here again, the basic patterns of Table 11 obtain. 30 Table 11: Predicting Post-secondary educational attainment using self-report and transcript measures No Post-secondary schooling by age 21 Highest Grade Completed at age 21 Self-Report HS Graduation Transcript HS Graduation Self-Report Number of Schools Transcript Number of Schools Male Hispanic Black Mother’s Ed. 12 years Mother’s Ed. > 12 years NCentral (at age 21) South (at age 21) West (at age 21) ASVAB missing ASVAB 25-75% ASVAB > 75% Constant -2.620** (0.11) 2.691** (34.2) -2.273** (0.09) 2.348** (30.26) 0.629** (0.05) -0.479 (10.29)** 0.154** (0.04) 0.524** 0.531** 0.595** 0.587** (0.07) (0.07) (0.06) (0.06) -0.016 -0.139 -0.175* -0.159 (0.10) (0.09) (0.09) (0.09) -0.213* -0.146 -0.187* -0.157* (0.09) (0.09) (0.08) (0.08) -0.193* -0.253** -0.400** -0.416** (0.09) (0.08) (0.08) (0.08) -1.169** -1.221** -1.363** -1.363** (0.09) (0.09) (0.08) (0.08) 0.266** 0.265** 0.201* 0.204* (0.10) (0.10) (0.09) (0.09) 0.125 0.088 0.069 0.052 (0.09) (0.09) (0.08) (0.08) -0.067 -0.042 -0.238* -0.172 (0.11) (0.10) (0.10) (0.10) -0.708** -0.710** -0.720** -0.734** (0.10) (0.10) (0.09) (0.091) -1.037** -1.091 ** -1.287** -1.308** (0.09) (0.09) (0.08) (0.08) -2.194** -2.303** -2.559** -2.626** (0.13) (0.13) (0.12) (0.12) 2.503** 3.013** 0.248 0.877** (0.14) (0.16) (0.13) (0.12) N=5578 N=5748 N=5748 N=5748 -2LogL -2LogL -2LogL -2LogL = 5374 = 7778 =6177 Logistic Regression Logistic Regression Standard errors given Standard errors given in in parentheses parentheses -0.125 (-2.93)** -0.391 (-6.19)** 0.034 (0.37) 0.188 (2.24)* 0.381 (4.46)** 0.889 (10.31)** -0.123 (-1.22) -0.088 (-0.94) 0.027 (0.25) 0.512 (5.05)** 1.126 (12.80)** 2.079 (19.32)** 11.709 (86.94)** N=5135 Rsq=0.14 OLS -0.384 (6.14)** 0.051 (0.56) 0.210 (2.52)* 0.357 (4.23)** 0.860 (10.1)** -0.115 (-1.15) -0.104 (-1.11) 0.066 (0.64) 0.481 (4.79)** 1.075 (12.32)** 1.974 (18.42)** 12.215 (87.88)** N=5135 Rsq=0.16 T-values given in parentheses -0.287** (-4.84) -0.018 (-0.21) 0.215** (2.72) 0.070 (0.86) 0.467** (5.70) -0.171 (-1.81) -0.146 (-1.66) -0.085 (-0.86) 0.311** (3.24) 0.604** (7.13) 1.349** (13.05) 10.390** (83.7) N=4989 Rsq=0.27 OLS -0.263** (-4.61) -0.041 (-0.50) 0.147 (1.94) 0.098 (1.27) 0.500** (6.36) -0.153 (-1.68) -0.100 (-1.18) -0.101 (-1.07) 0.334** (3.64) 0.627** (7.77) 1.387** (13.97) 9.950** (81.54) N=5135 Rsq=0.30 T-values given in parentheses 31 These two tables (11 and 12) suggest that although there may be considerable variability across the two sources in the coefficients of the disputed measures themselves, the choice of source may not induce great variability in other results. Table 12: Predicting post-high school employment using self-report and transcript measures Weeks Worked in year of 21st birthday Self-Report 4.632 HS Graduation (4.96)** Transcript 4.425 HS Graduation (4.92)** Male 1.095 1.219 (1.82) (2.01)* Hispanic 5.120 5.106 (4.28)** (4.22)** Mixed Race 0.082 1.132 (0.03) (0.35) Non-Hispanic, Non-Black 5.700 5.754 (6.20)** (6.19)** Mother’s Education: =12 2.286 2.158 years (2.61)** (2.42)* Mother’s Education: -0.576 -0.653 > 12 years (0.66) (0.74) NCentral (at age 21) 0.808 0.716 (0.92) (0.81) South (at age 21) -1.906 -2.143 (2.13)* (2.38)* West (at age 21) -1.919 -2.150 (1.91) (2.12)* ASVAB Percentile 0.002 -0.003 (0.13) (0.26) Constant 26.189 26.867 (19.11)** (19.79)** N=4225 N=4115 R-sq=0.03 R-sq=0.04 OLS Conclusions In this paper, we have examined selected constructs of high school experience for which measures can be constructed from self-report and transcript data in the NLSY97. We find that although the concordance rates vary and can be quite low for some measures, 32 neither source emerges strongly as the preferred ‘gold standard.’ Rather, each source is better at providing information about certain aspects about high school experience. We then consider the characteristics of youths with concordant vs. discordant data on selected measures. Mirroring previous work, we find evidence that students with better academic results are more likely to have matching self-report and transcript data. This systematic response error suggests that analytic results would likely be biased across the two sources (although it’s unclear which gives the more accurate estimate). With that in mind, we estimate a handful of regressions in order to illustrate the sensitivity of analytic results to the choice of data source. In summary, we find that although data can be quite different between self-report and transcript sources, neither is the clearly better source. 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