Item Response Theory
It was well-known to classical test theorists that measurement precision is not uniform across the scale of measurement. Tests tend to distinguish better for test-takers with moderate trait levels and worse among high- and low-scoring test-takers. Item response theory extends the concept of reliability from a single index to a function called the information function. The IRT information function is the inverse of the conditional observed score standard error at any given test score.
Read more about this topic: Reliability (psychometrics)
Famous quotes containing the words item, response and/or theory:
“The best way to teach a child restraint and generosity is to be a model of those qualities yourself. If your child sees that you want a particular item but refrain from buying it, either because it isn’t practical or because you can’t afford it, he will begin to understand restraint. Likewise, if you donate books or clothing to charity, take him with you to distribute the items to teach him about generosity.”
—Lawrence Balter (20th century)
“Perhaps nothing in all my business has helped me more than faith in my fellow man. From the very first I felt confident that I could trust the great, friendly public. So I told it quite simply what I thought, what I felt, what I was trying to do. And the response was quick, sure, and immediate.”
—Alice Foote MacDougall (1867–1945)
“Lucretius
Sings his great theory of natural origins and of wise conduct; Plato
smiling carves dreams, bright cells
Of incorruptible wax to hive the Greek honey.”
—Robinson Jeffers (1887–1962)