How letterpatronen works
Letterpatronen is one of the three parts of the cognitieve capaciteitentest (CCT), alongside woordrelaties and cijferpatronen. The police had the test built by the Belgian publisher Cebir. In letterpatronen you see a series of letters with two missing and type the two letters that complete it.
The test is adaptive. You start with a relatively easy question; a right answer brings a harder one and a wrong answer an easier one. Your score depends on how difficult the questions became, not on how many you answered, and the police warn that everyone finds the test hard in the end.
Each question has its own time limit: a few seconds for an easy one, several minutes for a hard one. No clock shows until ten seconds remain, when a bar runs in the top right. When it is full the test moves on, answered or not. You cannot go back, and you are not told whether you were right.
How to solve a letter pattern
Work through the same checks every time:
- Turn the letters into numbers, A = 1 to Z = 26, and write the gaps between them.
- Look for a constant step (+3), a step that grows (+1, +2, +3) or steps that alternate (+2, −1).
- If nothing fits, read every other letter. Two series are often woven together, one forwards and one backwards.
- Solve each gap on its own. The second missing letter may belong to a different series from the first.
- Check your two letters in place before the bar runs out.
Worked examples
Series: D ? H J ? N. As numbers: 4, ?, 8, 10, ?, 14. The step is +2 throughout, so the gaps are 6 and 12: F and L.
Series: B Y D W F U ? ?. Read positions 1, 3, 5: B, D, F, which climbs by 2. Positions 2, 4, 6: Y, W, U, which falls by 2. The next letters are H (8) and S (19).
Tips for letterpatronen
- Before you start, write the alphabet with its numbers 1 to 26 on scratch paper. Pen and paper are allowed, without limit.
- Always type something. An empty answer is marked wrong, and a guess costs nothing extra.
- Take your time over the instructions, which are not timed, but keep an eye on each question once it starts.
- Use a desktop or laptop. The police say smartphones are not suitable for this test.
- Do the test alone. Your result only counts after a short supervised verificatietoets on the selection day, which starts at the level you reached at home.
- Do the police’s free practice test on kombijdepolitie as well. It shows what the official test looks like.
Practise letterpatronen on CogniPrep
Our Letterpatronen is adaptive in the same way: it starts easy and runs 12 to 18 questions, ending once your level has settled. You type two letters into rows and small tables. The time limits, 25 seconds, 1 minute or 2 minutes by difficulty, are our estimate, because the police do not publish theirs, and no clock shows until the last ten seconds. At the end you get a score out of 100, driven mostly by the difficulty you reached, and a percentile against other CogniPrep players.