How Students' Average Book Level Is Calculated

One of the goals that you can set for students in Accelerated Reader is the average book level of the student's reading practice.

Each student's average book level is weighted based on the word count of each book read. Only quizzes that the student passed are included in the calculation:

[Sum of (word count x book level x % correct)] / [Sum of (word count x % correct)]

For example, a student with a Star Reading Grade Equivalent score of 8.0 is likely to have a Zone of Proximal Development range of 4.5-8.0. That student might read the following books and receive these scores on the Reading Practice Quizzes:

Title Author ATOS Book Level Points Word Count % Correct
Black Beauty (Unabridged) Sewell, Anna 7.7 11.0 59,635 100
Little Women (Book I and II) Alcott, Louisa May 7.9 33.0 183,833 100
Hansel & Gretel Grimm, Brothers 4.8 0.5 2,826 100
Sword in the Stone White, T.H. 7.5 16.0 90,876 100
Jungle Book II, The Kipling, Rudyard 8.0 11.0 63,340 90

The student would have an average book level of 7.8:

Word count x book level x % correct Word count x percent correct
Black Beauty 59635 x 7.7 x 100% = 459189.5 59635
Little Women 183833 x 7.9 x 100% = 1452280.7 183833
Hansel & Gretel 2826 x 4.8 x 100% = 13564.8 2826
The Sword in the Stone 90876 x 7.5 x 100% = 681570.0 90876
The Jungle Book II 63340 x 8.0 x 90% = 456048.0 57006
Sums 3062653.0 394176
Divide the sums: 3062653 ÷ 394176 = 7.76 (round to 7.8)

Weighting the calculation gives teachers a better indicator of where the student spent the majority of the time reading. This should encourage students to read throughout their ZPD ranges. More weight is given to books that are longer and possibly more challenging for the student. Also, when students want to enjoy a lighter, easier reading experience (such as a best-seller that the student's friends are reading), the book won't have as much weight as more challenging titles that the student might spend several days or even weeks reading.

The calculation can also be encouraging to students who might have been hesitant to help a peer or younger student with Read To or Read With practice. If tutors quiz on shorter or lower-level books than they usually read, the result will not have a drastic effect on their average.