Winsteps Help for Rasch Analysis

Winsteps Help for Rasch Analysis

Control Variable Index

Control Variable Index by function

Control variables from Specification menu

Output Table Index

Output Graphs and Plots Index

Output Files Index

Introduction

Rasch analysis and WINSTEPS

About the Users' guide

Getting further help

Installation and Execution

What is supplied

Installation instructions for WINSTEPS

Starting WINSTEPS in Windows

Using Winsteps under Windows

Uninstalling WINSTEPS

Stopping WINSTEPS

Menus

Data Setup menu

Excel/S-S-S menu or dialog

Output Files menu

Output Tables menu

Specification menu

Control and Data File Setup

Control and data file setup window

Reading in a pre-existent control file

Category labels

The Control and Data Files

Constructing Winsteps Control and Data files

Do-it-yourself control and data file construction

Control file and template.txt

Data from Excel-S-S-S files

Data from Excel files

Data from SAS files

Data from SPSS files

Data from STATA files

Data from Excel and other spreadsheets

Data file with other delimiters

Examples of Control and Data Files

Example 0: Rating scale data: The Liking for Science data

Example 1: Dichotomous data: Simple control file with data included

Example 2: Control and anchor files

Example 3: Item recoding and item deletion

Example 4: Selective item recoding

Example 5: Scoring key for items, also CAT responses

Example 6: Keys in data record FORMAT

Example 7: A partial credit analysis

Example 8: Items with various rating scale models

Example 9: Grouping and modeling items

Example 10: Combining tests with common items

Example 11: Item responses two characters wide

Example 12: Comparing high and low samples with rating scales

Example 13: Paired comparisons as the basis for measurement

Example 14: Multiple rescorings, response structures and widths

Example 15: Figure skating: Multidimensionality, DIF or Bias

Example 16: Disordered categories - thresholds and person anchoring

Example 17: Rack, stack, principal components

Control Variables

ALPHANUM alphabetic numbering

ASCII characters

ASYMPTOTE item upper and lower asymptotes

BATCH Batch mode analysis

BYITEM display graphs for items

CATREF reference category for Table 2

CFILE scored category label file

CHART graphical plots in Tables 10, 13-15

CLFILE codes label file

CODES valid data codes

CONVERGE select convergence criteria

CSV comma-separated values in output files

CURVES probability curves for Table 21 and Table 2

CUTHI cut off responses with high probability of success

CUTLO cut off responses with low probability of success

DATA name of data file

DELIMITER data field delimiters

DIF columns within person label for Table 30

DISCRIMINATION item discrimination

DISFILE category/distractor/option count file

DISTRACTOR output option counts in Tables 10, 13-15

DPF columns within item label for Table 31

EDFILE edit data file

END LABELS or END NAMES

EQFILE code equivalences

EXTRSC extreme score correction for extreme measures

FITHIGH higher bar in charts

FITI item misfit criterion

FITLOW lower bar in charts

FITP person misfit criterion

FORMAT reformat data

FORMFD the form feed character

FRANGE half-range of fit statistics on plots

GRFILE probability curve coordinate output file

GROUPS or ISGROUPS assigns items to rating scale groupings

GRPFROM location of ISGROUPS

GUFILE (G0ZONE, G1ZONE) Guttmanized response file

HEADER display or suppress subtable headings

HIADJ correction for top rating scale categories

HLINES heading lines in output files

IAFILE item anchor file

IANCHQU anchor items interactively

ICORFILE item residual correlation file

IDELETE item one-line item deletion

IDELQU delete items interactively

IDFILE item deletion file

IDROPEXTREME drop items with extreme scores

IFILE item output file

ILFILE item label file

IMAP item label on item maps Tables 1, 12

INUMB label items by sequence numbers

IPMATRIX response-level matrix

IREFER identifying items for recoding

ISELECT item selection criterion

ISFILE item structure output file

ISORT column within item name for alphabetical sort in Table 15

ISUBTOTAL columns within item label for subtotals in Table 27

ITEM title for item labels

ITEM1 column number of first response

ITLEN maximum length of item label

IVALUEx recoding of data

IWEIGHT item (variable) weighting

KEYFROM location of KEYn

KEYn scoring key

KEYSCR reassign scoring keys

LCONV logit change at convergence

LINLEN length of printed lines in Tables 7, 10-16, 22

LOCAL locally restandardize fit statistics

LOGFILE accumulates control files

LOWADJ correction for bottom rating scale categories

MAKEKEY construct MCQ key

MATRIX correlation output format

MAXPAGE the maximum number of lines per page

MFORMS reformat input data

MHSLICE Mantel-Haenszel slice width

MISSCORE scoring of missing data codes

MJMLE maximum number of JMLE iterations

MNSQ show mean-square or standardized fit statistics

MODELS assigns model types to items

MODFROM location of MODELS

MPROX maximum number of PROX iterations

MRANGE half-range of measures on plots

NAME1 first column of person label

NAMLEN length of person label

NAMLMP name length on map for Tables 1, 12, 16

NEWSCORE recoding values

NI number of items

NORMAL normal distribution for standardizing fit

OSORT option/distractor sort

OUTFIT sort misfits on infit or outfit

PAFILE person anchor file

PAIRED correction for paired comparison data

PANCHQU anchor persons interactively

PCORFIL person residual correlation file

PDELETE person one-line item deletion

PDELQU delete persons interactively

PDFILE person deletion file

PDROPEXTREME drop persons with extreme scores

PERSON title for person labels

PFILE person output file

PMAP person label on person map: Tables 1, 16

PRCOMP residual type for principal components analyses in Tables 23, 24

PSELECT person selection criterion

PSORT column within person label for alphabetical sort in Table 19

PSUBTOTAL columns within person label for subtotals in Table 28

PTBISERIAL compute point-biserial correlation coefficients

PVALUE proportion correct or average rating

PWEIGHT person (case) weighting

QUOTED quote-marks around labels

RCONV score residual at convergence

REALSE inflate S.E. for misfit

RESCORE response recoding

RESFROM location of RESCORE

RFILE scored response file

SAFILE item structure anchor file

SAITEM item numbers in SAFILE with one grouping

SANCHQ anchor category structure interactively

SCOREFILE person score file

SDELQU delete category structure interactively

SDFILE category structure deletion file

SFILE category structure output file

SICOMPLETE simulate complete data

SIEXTREME simulate extreme scores

SIFILE simulated data file

SINUMBER number of simulated data files

SISEED simulated data seed

SPFILE supplementary control file

STBIAS correct for estimation bias

STEPT3 include category structure summary in Table 3.2 or 21

STKEEP keep non-observed intermediate categories in structure

T1I# number of items summarized by "#" symbol in Table 1

T1P# number of persons summarized by "#" symbol in Table 1

TABLES output tables

TARGET estimate using information-weighting

TFILE input file listing tables to be output

TITLE title for output listing

TOTALSCORE show total scores with extreme observations

TRPOFILE transposing the data matrix

TRPOTYPE transposing specifications

UANCHOR anchor values supplied in user-scaled units

UASCALE the anchor user-scale value of 1 logit

UCOUNT number of unexpected responses: Tables 6, 10

UDECIMALS number of decimal places reported

UIMEAN the mean or center of the item difficulties

UPMEAN the mean or center of the person abilities

USCALE the user-scaled value of 1 logit

W300 Output files in Winsteps 3.00 format

WHEXACT Wilson-Hilferty exact normalization

XFILE analyzed response file

XMLE consistent, almost unbiased, estimation

XWIDE columns per response

@Field name for location in label

&END end of control variables

&INST start of control instructions

The Iteration Screen

The Iteration Screen

Output Tables

Table 1.0, 1.2, 1.3, 1.10, 1.12 Distribution maps

Table 1.1, 1.4 Distribution maps

Table 2 Multiple-choice distractor plot

Table 2 Most probable, expected, cumulative, structure, average measures

Table 3.1Summaries of persons and items

Table 3.2 Summary of rating scale category structure

Table 4.1, 5.1, 8.1, 9.1 Fit plots

Table 5.2, 9.2 Fit plots

Table 6.1 Person statistics

Table 6.2, 10.2, 13.2, 14.2, 15.2, 17.2, 18.2, 19.2, 25.2 Person and item statistics

Table 6.5 Most unexpected observations

Table 6.4, 10.4 Most misfitting response strings

Table 6.6, 10.6 Most unexpected response list

Table 7.1, 11.1 Misfitting responses

Table 7.2, 17.3, 18.3, 19.3 Diagnostic KeyForms for Persons

Table 10.1 Item statistics

Table 10.3, 13.3, 14.3, 15.3, 25.3 Item option/distractor frequencies

Table 10.5 Most unexpected observations

Table 12.2, 12.12 Item distribution maps

Table 12.5 Item map with expected score zones

Table 12.6 Item map with 50% cumulative probabilities

Table 13.1, 14.1, 15.1, 25.1, 26.1 Item statistics

Table 16.3 Person distribution map

Table 17.1, 18.1, 19.1 Person statistics

Table 20.1 Complete score-to-measure table on test of all items

Table 20.2 Person score and measure distribution

Table 20.3 Complete score-to-calibration table for tests based on whole sample

Table 21 Probability curves

Table 22.1 Sorted observed data matrix (scalogram)

Table 22.2 Guttman scalogram of zoned responses.

Table 22.3 Guttman scalogram of original codes

Table 23.0 Variance components scree plot for items

Table 23.2, 24.2 Principal components plots of item or person loadings

Table 23.3, 24.3 Principal components analysis/contrast of residuals

Table 23.4, 24.4 Person or item contrast

Table 23.99, 24.99 Largest residual correlations for items or persons

Table 24.0 Variance components scree plot for persons

Table 27.1 Item subtotal summaries on one line

Table 27.2 Item subtotal measure bar charts

Table 27.3 Item subtotal detailed summary statistics

Table 28.1 Person subtotal summaries on one line

Table 28.2 Person subtotal measure bar charts

Table 28.3 Person subtotal detailed summary statistics

Table 29 Empirical ICCs and option frequencies

Table 30.1 Differential item functioning DIF pairwise

Table 30.2 Differential item functioning DIF list

Table 30.3 Differential item functioning DIF list

Table 30.4 Differential item functioning DIF fit summary

Table 31.1 Differential person functioning DPF pairwise

Table 31.2 Differential person functioning DPF list

Table 31.3 Differential person functioning DPF list

Table 31.4 Differential person functioning DPF fit summary

Table 32 Control specifications

Table 33.1 Differential group functioning DGF pairwise

Table 33.2 Differential group functioning DGF pairwise

Table 33.3 Differential group functioning DGF list

Table 33.4 Differential group functioning DGF list

Table 34 Columnar statistical comparison and scatterplot

Table 0 The title page

Table 0.1 Analysis identification

Table 0.2 Convergence report

Table 0.3 Control file

Graphs

Category information function

Conditional probability curves

Cumulative probabilities

Empirical category curves

Empirical randomness

Expected score ICC

Item information function

Multiple item ICCs

Non-uniform DIF ICCs

Points and lines

Probability category curves

Test characteristic curve

Test information function

Test randomness

Plots

Compare statistics

Datapoint labels

DGF DIF-DPF Plot

Output dialogs

DGF specifications

DIF specifications

DPF specifications

Edit Initial Settings (Winsteps.ini) file

Output file specifications

Transpose file specifications

Special Topics

Advice to novice analysts

Anchored estimation

Automating file selection

Average measures, distractors and rating scales

Batch mode example: Score Tables

Biserial correlation

Category boundaries and thresholds

Column and classification selection and transformation

Comparing tests or instruments

Comparing estimates with other Rasch software

ConstructMap (GradeMap) interface

Convergence considerations

Correlations: point-biserial, point-measure, residual