ABSTRACT Assessment items are commonly field tested prior to operational use to observe statistical item properties such as difficulty. Item parameter estimates from field testing may be used to assign scores via pre-equating or computer adaptive designs. This study examined differences between item difficulty estimates based on field test and operational data and the relationship of such differences to item position changes and student proficiency estimates. Item position effects were observed for 20 assessments, with items in later positions tending to be more difficult. Moreover, field test estimates of item difficulty were biased slightly upward, which may indicate examinee knowledge of which items were being field tested. Nevertheless, errors in field test item difficulty estimates had negligible impacts on student proficiency estimates for most assessments. Caution is still warranted when using field test statistics for scoring, and testing programs should conduct investigations to determine whether the effects on scoring are inconsequential.

中文翻译：

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嵌入式现场测试项目统计信息：可以信赖它们来评估学生的水平吗？

摘要评估项目通常在操作使用之前进行现场测试，以观察统计项目的属性，例如难度。来自现场测试的项目参数估计值可用于通过预先确定或计算机自适应设计来分配分数。这项研究检查了根据实地测试和操作数据得出的项目难度估计之间的差异，以及此类差异与项目位置变化和学生熟练程度估计之间的关系。在20个评估中观察到了项目位置的影响，后期位置的项目往往更困难。此外，项目难度的现场测试估计值略有偏向，这可能表明考生对哪些项目正在现场测试的知识。尽管如此，在大多数评估中，现场测试项目难度估计中的错误对学生熟练度估计的影响可以忽略不计。在使用现场测试统计数据进行评分时，仍需谨慎，测试程序应进行调查以确定对评分的影响是否无关紧要。