Informal decoding inventory: what it shows and how to use it

How is a decoding inventory different from a phonics survey?

The two overlap a lot, and people use the names loosely. In practice, a decoding inventory usually goes further into multisyllable words. It has a single-syllable part and a separate part with two- and three-syllable words sorted by syllable type.

That second part is what makes it useful for grades 3 to 8. Many older students read one-syllable words well and fall apart on longer words. A short phonics survey can miss that completely.

What does the inventory cover?

Each section mixes real and made-up words, since made-up words keep students from reading from memory. For older students, explain the made-up words honestly before you start. They are a fair test of decoding, and most teens appreciate knowing why they're being asked to read them.

How do you give it without wasting time?

1. For grades 3 and up, start with the multisyllable part. If the student does well, skip the single-syllable part.
2. If the multisyllable part falls apart, go back and give the single-syllable sections.
3. Mark errors by writing what the student said.
4. Stop a section after several misses in a row.
5. Note self-corrections and long pauses. They show patterns that are partly known.

How do you read the results?

Score each section as a percentage. Then look for the lowest section where the student is still mostly accurate. Teaching usually starts at the first section that falls below about 80 percent.

The error notes tell you what to teach inside that section. These four patterns come up again and again with students in the upper grades.

• Vowel errors in closed syllables ("rab" for "rib"): short vowels need work, even in older students.
• Dropped syllables in long words: the student needs a routine for finding and reading each syllable.
• Wrong syllable division ("ca-bin" read as "cab-in" works, "ro-bot" read as "rob-ot" doesn't): teach flexing between long and short vowel sounds.
• Suffix errors: teach common suffixes as units.

What does an inventory not tell you?

It doesn't measure speed, so pair it with a timed oral reading passage at grade level. It doesn't measure comprehension or vocabulary either, and it isn't a test for any disability.

It also won't predict how fast a student will catch up. Progress monitoring after instruction starts is what answers that.

How often should you give it again?

Give the full inventory once, at the start. Then recheck only the sections you have taught, about every 6 to 8 weeks. That keeps the testing short and the results tied to your teaching.

What do you need before you start?

You need a student copy in a clear, large font with plenty of space between words, and a teacher copy where you can write each error. Leave out pictures. A clipboard keeps your marks out of sight, which matters for older students who watch the pen closely and lose heart when they see many marks.

Plan for 10 to 20 minutes. If the student is tired or upset, stop and finish another day. A rushed inventory gives you errors that come from stress rather than from missing skills.

Why do older students miss long words they can almost read?

Usually because they never learned a way to break a long word into parts. Many older students read the first syllable and guess the rest from the word's shape. That works for familiar words and fails on new vocabulary in science or history, which is exactly where the reading load grows from fourth grade on.

The inventory exposes this quickly. A student who reads short closed-syllable words perfectly but misreads two-syllable words built from the same parts needs a syllable routine, not more one-syllable phonics.

How do you share results with the student?

Tell older students what you found in plain words and show them the plan. Most have spent years feeling vaguely bad at reading. Hearing that they know most short-word patterns and need a method for long words is specific, fixable, and much easier to accept.