IRIs are easy to find or even to develop. Several authors have published IRIs for use by teachers, tutors or mentors. These include the Ekwall/Shanker Reading Inventory and the Qualitative Reading Inventory, for example. Informal Reading Inventories also have been developed by many teachers. Furthermore, teachers can create their own Informal Reading Inventories simply by choosing a graded word list to begin the assessment, gathering passages of 50 to 200 words at each reading level to be assessed, and writing comprehension questions that assess the student's ability to recall details, make inferences and demonstrate knowledge of grade level vocabulary.
Informal Reading Inventories are considered uncomplicated and easily-administered assessments. Instructions are included with commercial inventories and can be read and followed by professionals, volunteers and parents. No special training is needed to administer an IRI. Most IRIs are designed for individual administration and take between 5 to 30 minutes to complete. IRIs that include silent reading portions can be used for group assessments, as well. They can be used to assess both silent and oral reading, fluency, comprehension and word analysis skills.
Because Informal Reading Inventories are criterion-referenced tests, they are easily scored. Incorrectly read words are noted for later analysis, reading time is written down and converted to a fluency score and comprehension questions are counted as correct or incorrect. The test returns results in terms of Independent, Instructional and Frustration Reading Grade Levels, which are calculated by comparing the percent of correctly read words and the percent of correctly answered questions to a standard scale. Students who read with 99 to 100 percent accuracy and answer 90 percent or more of the questions are reading at the Independent Level. Students who read between 96 and 98 percent of the words correctly or can answer 60 to 89 percent of the questions are reading at the Instructional Level and may need some assistance with the reading. Students who read 95 percent or fewer of the words correctly or respond correctly to 59 percent or less of the questions are at the Frustration Level and should not be expected to read that material on their own.
Informal Reading Inventories, if scored and analyzed correctly, provide the teacher or tutor with a wealth of information about the student's reading skills. The overall scores offer insight into what level of reading material the student should be expected to read successfully. Teachers can analyze the responses to comprehension questions to gather information about the student's ability to recall detail, to make inferences and to use grade-level vocabulary skills. Conduct error analysis on the oral reading portions of the test to discover strengths and weaknesses in sight word recognition, phonics skills, word attack and syllabication skills, phrasing ability, visual tracking and attention to punctuation. Use the information gathered from the Informal Reading Inventory to assess student progress, plan intervention and evaluate the outcomes of special programs.