Since 2009, as part of the data collection effort for its reading assessment report on the nation's students, the National Assessment of Educational Progress has been administering a vocabulary test in an effort to determine if there is a relationship between literacy level and word knowledge for American kids.
Prior to 2009, a limited number of vocabulary questions were included as part of the assessment. However, 2009 was the first time that a vocabulary question framework was included in the assessment that was detailed down to the type of questions — and how many — that students should be asked.
The goal was to determine if understanding the meaning of words would bolster the students' ability to figure out the meaning of a passage that contained those words.
This systematic assessment of vocabulary allows NAEP to more fully assess the impact of vocabulary knowledge on student's comprehension and makes it possible to report on students' vocabulary performance. In addition to the inclusion of vocabulary questions in the comprehension assessment, additional sections containing all vocabulary questions were also included in the assessment.
During the assessment – which runs every two years – data was collected from a nationally representative sample of over 110,000 fourth-graders, 103,000 eighth-graders and 44,500 twelfth-graders. In 2011, a larger sample of fourth-graders and eighth-graders was surveyed, although no assessment was run on kids in the 12th grade.
The vocabulary questions typically quoted a sentence from an included passage, with one word highlighted, and asked students to choose the meaning of the word from four options.
The NAEP reading framework acknowledges the association between vocabulary and reading comprehension. At its most fundamental level, reading comprehension (the ability to understand what one has read) requires knowing the meaning of words. To comprehend what they read, students must integrate their knowledge or sense of words as they are used in particular passages to understand the overall topic or theme. Understanding key words that support the main idea or theme and details that contribute shades of meaning further enhance comprehension to create a richer experience. This association is reflected in the results that show that on average students who performed well on the vocabulary questions also performed well in reading comprehension.
The results showed that high reading comprehension scores often went hand-in-hand with a good knowledge of vocabulary. At the same time, students who scored poorly on literacy and reading comprehension also frequently had poor vocabulary scores.
Fourth-graders who in 2011 tested in the top 25% of all students in literacy were also some of the highest scorers on the vocabulary portion of the assessment. The reverse was also true. Those whose reading comprehension scores fell in the bottom 25% had similarly low vocabulary scores.