The science

Phonics in the SATPIN order, and why most apps get it wrong

By Ryan King · Updated June 2026 · Sourced.

The classic synthetic phonics order is s, a, t, p, i, n. Most consumer reading apps still introduce letters alphabetically. The difference shows up faster than you would think.

Why not the alphabet

If the goal is to teach a child to read words as quickly as possible, the alphabet is the wrong order to introduce letters. The first three letters in the alphabet, a, b, c, do not combine into many useful words. A child who knows a, b, and c can read 'cab' and very little else.

The SATPIN order, used by the Letters and Sounds program that England's primary schools use, was designed around a different goal: maximize the number of decodable words a child can read after each letter is learned.

What SATPIN gives you

After s, a, and t, a child can read 'sat', 'at', and 'as'. After p, the words 'pat', 'tap', 'sap', 'past', and 'taps' join the list. After i, words like 'sit', 'pit', 'tap', 'tip', 'pat', and 'sip' all become decodable. After n, 'nap', 'pan', 'pin', 'tin', 'in', 'sin', and 'span' open up.

By the end of the first six letters the child has a working vocabulary of roughly thirty real decodable words. That changes what kind of practice the program can offer. There are real sentences a child can read by the end of week one, not picture-only review.

Why most apps still teach alphabetically

Three reasons. The alphabet is what parents recognize, so an app that opens with A B C feels familiar in a store listing. Alphabetical order is easier to design content for because there are existing alphabet-themed art assets, songs, and merch. And most app publishers do not actually intend to teach a child to read. They intend to teach a child to recognize letters in some order, which feels close enough.

Recognizing letters is necessary for reading. It is not sufficient. A child who can identify every letter of the alphabet but cannot blend or decode has not learned to read. The order matters because it determines whether the child gets to the blending stage in week one or week twelve.

What Cairn Read does with this

Cairn Read introduces letters in the SATPIN order across six groups of letters: s a t p, i n m d, g o c k, e u r h, b f l j, and v w x y z q. Each group unlocks once the child has mostly mastered the previous group, where 'mostly' means they got at least 60 percent of the letters in that group correct on the first try twice in a row.

The decodable words and sentences in the game expand with each unlock. A child sees only words they can actually read, even when they switch from Letter Hunt to Sentence Quest. The first sentence the average 4-year-old reads in Cairn is 'The cat sat.' It is a small thing. It also is not.

Sources: Letters and Sounds (2007), United Kingdom Department for Education; Jolly Phonics; Ehri (2005), Learning to Read Words, Scientific Studies of Reading.