Typing Glossary: WPM, CPM, raw speed, IKI, home row and more
Plain-English definitions of the terms typing tools throw at you, including the ones they rarely explain.
Touch typing
- Typing without looking at your hands, using a fixed assignment of fingers to keys so the movement becomes automatic. The defining feature is not speed but that the keyboard is located by feel, via the home-row anchor keys, rather than by sight.
WPM (words per minute)
- The standard measure of typing speed: correctly typed characters divided by five, scaled to one minute. Five characters is the conventional definition of a "word", so WPM is comparable across languages and texts of different word lengths.
Raw WPM
- The same calculation as WPM but counting every keystroke, including incorrect ones. The gap between raw and net WPM quantifies exactly how much speed your errors are costing.
CPM (characters per minute)
- Typing speed expressed in characters rather than five-character words. CPM is simply WPM multiplied by five, and is more common outside English-language typing tools.
Accuracy
- The percentage of keystrokes that were correct on the first attempt. Because every error costs a backspace, a re-read and a break in rhythm, accuracy affects real-world throughput more than headline speed does.
Consistency
- How even your typing pace is, derived from the variation in the interval between successive keystrokes. High consistency means a steady rhythm; low consistency means bursts of familiar words separated by stalls, which is where most lost time actually hides.
Inter-key interval (IKI)
- The time in milliseconds between one keystroke and the next. The distribution of inter-key intervals across a session is the raw material for consistency scoring, rhythm fingerprints and hesitation detection.
Hesitation
- A keystroke interval far longer than your own typical pace. The moment where you stopped to think or search for a key. Hesitations are more diagnostic than errors, because they show which keys are not yet automatic.
Home row
- The middle row of letter keys where all eight fingers rest between reaches. On QWERTY it is A S D F and J K L semicolon. Every other key in touch typing is learned as a movement relative to this row.
Anchor keys
- The two keys carrying small tactile bumps, F and J on QWERTY, that the index fingers use to locate the keyboard by feel. They are what makes typing without looking possible.
Bigram
- A pair of consecutive letters, such as "th" or "er". Bigram timings reveal which transitions between specific keys are slow, which is usually more actionable than knowing which individual keys are slow.
Rollover
- Pressing the next key before fully releasing the previous one. Overlapping keystrokes this way is a hallmark of fluent typing, and keyboards are rated by how many simultaneous keys they can register correctly.
Burst speed
- Your peak speed over a short window, often a familiar word or common bigram, as opposed to your sustained average. A large gap between burst and average speed indicates that specific keys or transitions, not general ability, are the limiting factor.
Key mastery
- A per-key state describing how reliable a key is for you, based on its error rate and typical timing. In KeyTopia keys move through learning, improving, reliable and mastered states, and fall back to needs-review when performance degrades.
Adaptive practice
- Practice text generated from your own performance data rather than a fixed script, so that weak keys and slow transitions receive more repetitions than keys you already own.
Placement test
- A short assessment taken before training that measures current speed, accuracy, rhythm and per-key reliability in order to choose a realistic starting point in the curriculum.
Ghost run
- A replay of one of your own previous sessions raced alongside your current attempt, so improvement is visible in real time against your former self rather than against a stranger.
Keyboard layout
- The mapping of physical keys to characters. QWERTY, QWERTZ and AZERTY are regional variants; Dvorak and Colemak are alternative layouts designed to reduce finger travel. Touch-typing instruction must match the layout you actually use.