Table 31.5, 31.6 Within-class fit report

Table 31.5 Within-class fit report (item class within person).

Table 31.6 Within-class fit report (person class within item)

 

DIF class specification is: DIF=@GENDER

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| TAP       OBSERVATIONS    BASELINE         DPF       DPF      W-INFIT    W-OUTFIT  KID             |

| CLASS    COUNT AVERAGE EXPECT MEASURE      SIZE      S.E.   MNSQ  ZSTD  MNSQ  ZSTD Number  Name    |

|----------------------------------------------------------------------------------------------------|

| 1           11     .18    .23   -2.94      -.60      1.05    .71  -.53   .25  -.31      1 Adam    M|

 

For a general description, see Table 31.2

 

The DPF effects are shown ordered by CLASS within person (row of the data matrix).

 

TAP CLASS identifies the CLASS of items. KID is specified with ITEM=, e.g., the first CLASS is "1-"

OBSERVATIONS are what are seen in the data

COUNT is the number of observations of the classification used for DPF estimation, e.g., 11 "1-" items responses were made by person 1.

AVERAGE is the average observation on the classification, e.g., 0.18 is the average score class "1-' items by person 1.

COUNT * AVERAGE = total score of person on the item class.

BASELINE is the prediction without DPF

EXPECT is the expected value of the average observation when there is no DPF, e.g., 0.92 is the expected average for person 1 on item class "1-" without DPF.

MEASURE is the what the overall ABILITY measure would be without DPF, e.g., -2.94 is the overall person ability of person 1 as reported in Table 18.

 

DPF SIZE is the size of the DPF

DPF S.E. is the S.E. of the DPF size

 

W-INFIT is the Within-Group infit statistic for the item CLASS on the person.

W-OUTFIT is the Within-Group outfit statistic for the item CLASS on the person.

MNSQ is the mean-square statistic (chi-square divided by its degrees of freedom).

ZSTD is the mean-square statistic expressed as a z-score (unit normal deviate).