Page 180 - BUKU SYNOPSIS

Figure 19. Probability Curve

Figure 19 depicts a constant stretch for each scale, indicating that the

established rating scale is appropriate for evaluating students and is

easily understood by raters. In addition, the figure depicts that each rating

scale has its own apex. Overall, it indicates that the grading rubric is

acceptable for use with students' argumentative writings.

In addition, the category statistics table of MFRM reveals that the

values of Rasch-Thurstone Thresholds for rating scales 1 to 4 range from

low to -2.54, .09, and 2.43, respectively. The values suggest that raters

comprehended the descriptions of each scale well.

2) Reliability

A writing assessment task is considered reliable if it consistently

measures the same student on two or more occasions and the same task

by different raters (Bachman & Palmer, 1996; Knoch, 2009; Weigle,

2002). In short, the extent to which test-takers receive the same score

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