​​​​​NAEP Technical DocumentationScience Assessment Estimation Variables for 2019

Variables used in the population-structure model for the 2019 science assessment are listed below. The same population-structure model was used for both the digitally based (DBA) and paper-based (PBA) versions of the assessment. All of the variables below are included as main effects.

Each main effect listed in this section was paired with every other main effect in this section to examine interactions:

  • ACCOM2 – Accommodated. Three levels: Accommodated, Not accommodated and Excluded, and Missing.
  • CENSREG – Region of the country as defined by U.S. Census. Five levels: Northeast, Midwest, South, West, and Missing.
  • CHRTRPT – School identified as charter school (national public). Three levels: Charter school, Not a charter school, and Missing.
  • DSEX – School-reported gender. Three levels: Male, Female, and Missing.
  • IEP – Whether student is classified as having a disability. Four levels: Student with disability (has IEP or 504 plan), Not student with disability, Omitted, and Missing.
  • LEP – Whether student is classified as English learner. Four levels: English learner, Not English learner, Omitted, and Missing.
  • PARED (grades 8 and 12 only) – Highest level of education achieved by either parent. Eight levels: Did not finish high school, Graduated high school, Some education after high school, Graduated college, I don't know, Omitted, Multiple, and Missing.
  • SCHTYPE – Type of school. Six levels: Public, Catholic, Other private, Bureau of Indian Education, Department of Defense, and Missing.
  • SLUNCH1 – National School Lunch Program eligibility. Four levels: Eligible, Not eligible, Information not available, and Missing.
  • SRACE10 – School-reported race/ethnicity. Eight levels: White, Black, Hispanic, Asian, American Indian/Alaska Native, Native Hawaiian/Other Pacific Islander, Two or more races (not Hispanic), and Missing.
  • UTOL4 – School location. Six levels: City, Suburb, Town, Rural, Omitted, and Missing.

At grade 4 only, the main effect listed in this section was used to examine interactions with CENSREG, DSEX, SLUNCH1, and UTOL4:

  • SINQ04 – Student average response to statements regarding the frequency with which they do inquiry activities in science class. Five levels: Never, Sometimes, Often to always, Omitted, and Missing.

At grade 8 only, the main effect listed in this section was used to examine interactions with CENSREG, DSEX, SLUNCH1, and UTOL4:

  • SINQ08 – Student average response to statements regarding the frequency with which they do inquiry activities in science class. Five levels: Never, Sometimes, Often to always, Omitted, and Missing.

At grade 12 only, the main effect listed in this section was used to examine interactions with DSEX, SLUNCH1, and UTOL4:

  • SINQ12 – Student average response to statements regarding the frequency with which they do inquiry activities in science class. Six levels: Never, Sometimes, Often to always, Not taking science, Omitted, and Missing.

At grades 4 and 8 only, the main effects listed in this section were used to examine interactions with CENSREG and UTOL4:

  • TSEXPER – Teacher average response to statements regarding the emphasis placed on teaching science experiments. Five levels: No to very little emphasis, Some emphasis, Quite a bit to a lot of emphasis, Omitted, and Missing.
  • TSINQR – Teacher average response to statements regarding the frequency with which science students do inquiry activities. Five levels: Never to once or twice a year, Once or twice a month to once or twice a week, Once or twice a week to every day, Omitted, and Missing.

At grade 12 only, the main effect listed in this section was used to examine interactions with DSEX, SLUNCH1, SRACE10, and UTOL4:

  • K824301 – Student response to the question "How likely are you to pursue a career in science." Seven levels: Not at all likely, Not likely, Somewhat likely, Quite likely, Extremely likely, Omitted, and Missing.

At grade 12 only, the main effects listed in this section were used to examine interactions with K824301:

  • COLL2YR – Student applied or accepted to two-year college. Six levels: Accepted to two-year college, Applied to two-year college, Neither, Omitted, Multiple, and Missing.
  • COLL4YR – Student applied or accepted to four-year college. Six levels: Accepted to four-year college, Applied to four-year college, Neither, Omitted, Multiple, and Missing.

At grade 12 only, the main effect listed in this section was used to examine interactions with DSEX:

  • SCICRS2 – Science courses taken in high school. Five levels: Biology, Chemistry, and Physics; Biology and Chemistry; Biology or Other; Omitted; and Missing.

Variables used for main effects only:

  • Additional Accommodations Variables – Each of the following variables is scored as Yes or Missing: Bilingual dictionary, Bilingual test form (grades 4 and 8 only), Braille presentation, Breaks, Color contrast, Computer/typewriter to respond, Cue to stay on task, Directions read aloud in English, Directions read aloud in Spanish, Directions translated to Spanish (grades 4 and 8 only), Extended time, Hearing impaired version of test, High contrast version of test, Large print test booklet, Low mobility version of test, Magnification device, One-on-one, Other, Preferential seating, Read aloud in English [all], Read aloud in English [occasional], Read aloud in Spanish [all] (grades 4 and 8 only), School staff administers, Scribe, Separate session, Sign Language directions, Sign Language presentation, Sign Language response, Small group, Special equipment, and Template.
  • Additional Student Disability Classification Variables – Each of the following variables is scored as Yes or Missing: Autism, Brain injury, Developmental delay, Emotional disturbance, Hearing impairment, Intellectual disability, Other health disability, Orthopedic impairment, Specific learning disability, Speech impairment, and Visual impairment.
  • CENSDIV – Census division. Ten levels: New England, Middle Atlantic, East North Central, West North Central, South Atlantic, East South Central, West South Central, Mountain, Pacific, and Missing.
  • DRACE10 – Student-reported race/ethnicity. Eight levels: White, Black, Hispanic, Asian, American Indian/Alaska Native, Native Hawaiian/Other Pacific Islander, Two or more races (not Hispanic), and Missing.
  • EL – Status as English learner (EL). Four levels: Yes, No, Formerly EL, and Missing.
  • HISPYES – Hispanic. Four levels: Yes, No, Omitted, and Missing.
  • MODAGE – Modal age of most students in sample. Four levels: Below modal age, At modal age, Above modal age, and Missing.
  • PCTWHTC – Percentage of White students. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • PCTBLKC – Percentage of Black students. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • PCTHSPC – Percentage of Hispanic students. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • PCTASNC – Percentage of Asian students. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • PCTHPIC – Percentage of Hawaiian/Pacific Islander students. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • PCTINDC – Percentage of American Indian students. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • PCT2MRC – Percentage of students of Two or more races. Seven levels: 0%, 1–5%, 6–25%, 26–50%, 51% or more, Omitted, and Missing.
  • SD3 – Whether student has an Individualized Education Plan (IEP). Four levels: Has an IEP, Has a 504 plan, Does not have an IEP, and Missing.
  • SENROL4 (grade 4 only) – School enrollment. Six levels: 1–299 students, 300–499 students, 500–699 students, 700 or more students, Omitted, and Missing.
  • SENROL8 (grade 8 only) – School enrollment. Seven levels: 1–399 students, 400–599 students, 600–799 students, 800–999 students, 1000 or more students, Omitted, and Missing.
  • SENRL12 (grade 12 only) – School enrollment. Seven levels: 1–499 students, 500–999 students, 1,000–1,499 students, 1,500–1,999 students, 2,000 or more students, Omitted, and Missing.
  • SLUNCH – National School Lunch Program eligibility. Seven levels: Not eligible, Eligible for reduced-price lunch, Eligible for free lunch, Information not available, School refused to provide information, Not participating, and Missing.
  • UTOL12 – School location. Fourteen levels: Large city, Midsize city, Small city, Large suburb, Midsize suburb, Small suburb, Fringe town, Distant town, Remote town, Fringe rural, Distant rural, Remote rural, Omitted, and Missing.


Variables obtained from survey questionnaires and used for main effects only:


Last updated 19 December 2023 (PG)
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