Standardizing test scores for a target population: The LMS method illustrated using language measures from the SCALES project
Standardizing test scores for a target population: The LMS method illustrated using language measures from the SCALES project
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DOI：
10.1371/journal.pone.0213492
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发表时间：
2019-03-07
期刊：
影响因子：
3.7
通讯作者：
Pickles, Andrew
中科院分区：
文献类型：
--
作者：
Vamvakas, George;Norbury, Courtenay Frazier;Pickles, Andrew
百分位曲线和标准评分在流行病学研究中很常见。然而，反映整个英国本地学校人口的语言障碍的标准化规范和百分位数增长曲线并不存在。方法从量表人口调查中获得儿童接受和表达功能的六个语言指标得分。说单语英语的参与者年龄在5到9岁之间。在入学时就读特殊学校或将英语作为额外语言学习的儿童被排除在外。我们使用允许偏差测量的LMS标准化方法构建语言规范。我们使用了由两步逻辑模型产生的概率权重。对集中评估的亚群和全群的估计标准分数的分布进行了对比，以证明权重的作用。结果6项语言指标在各年龄段均获得不重叠的百分位曲线和标准化得分。在检索分数的目标分布时，使用权重是必不可少的。建立了一个在线计算器，可以估计这些措施的标准化分数，并免费提供。结论：研究结果突出了LMS方法在处理语言和教育措施标准化方面的有效性和灵活性，这些标准化措施是足够连续的。这篇论文补充了现有的文献，提供了从同一组个人中计算出的一些语言测试的总体规范。
BackgroundCentile curves and standard scores are common in epidemiological research. However, standardised norms and centile growth curves for language disorder that reflect the entire UK local school population do not exist.MethodsScores on six language indices assessing receptive and expressive functioning of children were obtained from the SCALES population survey. Monolingual English speaking participants were aged between five and nine years. Children who attended special schools at study intake, or who were learning English as an additional language were excluded. We constructed language norms using the LMS method of standardisation which allows for skewed measurements. We made use of probability weights that were produced from a two-step logistic model. Distributions of estimated standard scores from an intensively assessed sub population and from the full population were contrasted to demonstrate the role of weights.ResultsNon-overlapping centile curves and standardised scores at each age were obtained for the six language indices. The use of weights was essential at retrieving the target distribution of the scores. An online calculator that estimates standardised scores for the measures was constructed and made freely available.ConclusionsThe findings highlight the usefulness and flexibility of the LMS method at dealing with the standardisation of linguistic and educational measures that are sufficiently continuous. The paper adds to the existing literature by providing population norms for a number of language tests that were calculated from the same group of individuals.