The data file layout is a printable file that lists the name, position, format, and description of each data variable on the corresponding response data file. Below is a sample of a partial data file layout:
Seq. Field Col. Field Decimal Key no. name pos. width places Type Range value Short label 1 Year 1 2 0 C Assessment year 2 Age 3 2 0 C Assessment age 3 Book 5 3 0 C Booklet number 4 BKSER 8 6 0 C Booklet serial number
|NOTE: In the NAEP 2000 codebook file, AN="accommodations not provided", and AP="accommodations provided."
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2000.
Each line of the layout file contains the following information for a single data variable:
Sequence number: fields are numbered sequentially to represent the order in which they appear on the data record.
Field name: eight-character label for the field that is to be used consistently by all secondary-use data files materials.
Column position: relative location of the beginning of the data variable on each record using bytes or characters as the unit of measure.
Field width: indicates the number of columns used in representing the data value for a data variable.
Number of decimal places: If the field contains continuous numeric data, the value under the number of decimal places entry indicates how many places to shift the decimal point before processing data values.
Value range: If the field type is discrete numeric, the value range is listed as the minimum and maximum permitted values separated by a hyphen to indicate range.
Key or correct response value: If the field is a response to a scorable item, the correct option value, or key, is printed. If the field is an assigned score that was scaled as a dichotomous item using cut-point scoring, the range of correct scores is printed.