STL Assessment Practice

What STL runs, and what is in it

Sectorinstituut Transport en Logistiek is the Dutch sector institute for transport and logistics, and it runs assessment on behalf of the sector for the selection and recruitment of truck drivers.

Ixly publishes a case study on the programme, and it is one of the more concrete ones. STL runs a programme of five psychological tests including a reaction time test, a personality questionnaire and an intelligence test. About 25,000 candidates and 125,000 tests have gone through it since 2016, at around 1,800 deployments a year.

Two honest caveats. Ixly names three of the five and not all five, so this page describes what is documented rather than guessing at the rest. And we do not simulate the reaction time test: Ixly publishes a construct and a duration for its timed reaction and concentration instruments and essentially nothing about their mechanics, so building practice for one would mean inventing it. If a reaction time test is part of what you are sent, that stage is real and we are not preparing you for it.

What sitting an Ixly test is like

Everything runs through the Test-Toolkit. An invitation email carries a unique link, an overview screen lists the tests assigned to you and lets you choose the order, and a short questionnaire before the first one collects age, gender and education level. That last answer decides who you are compared against, so answer it accurately.

• Forty-five seconds per item. No overall clock, no banking time from an easy item for a hard one.
• An unanswered item counts as wrong. Ixly states this on the instruction screen. There is no blank to protect, so always put something down.
• You cannot go back, and stepping away does not pause the item's clock: you return to the next item.
• It adapts, getting harder as you succeed and stopping once it has measured you. Half right is a normal outcome.
• Each test starts with a worked example and three untimed practice items that tell you whether you were right. Take them seriously; they are the only part where nothing is being measured.
• Scratch paper is allowed, a calculator is not.

What comes back

A sten from 1 to 10, a T-score, a percentile and an IQ score, each with an 80% confidence interval. The sten has a mean of 5.5, which means a 5 is an average result and not a fail. Ixly's own manual warns candidates about this specifically, because a 5 on a Dutch school report is an onvoldoende and people carry that reading across.

Your comparison group is your education level: VMBO, MBO, HBO or WO. This matters a great deal for driver selection, where many candidates come through VMBO or MBO routes. Ixly's worked example takes one raw score and reports it as sten 8.3 and the 92nd percentile against the VMBO group, and sten 4.2 and the 25th percentile against the WO group. You are being measured against people with a comparable education, not against a graduate population.

How to prepare

Practise pacing before content

The cheapest marks on an Ixly test are the ones lost to expired items, because an expired item is scored as wrong. Build the habit of committing an answer at around 35 seconds, whatever state your reasoning is in.

The capacity tests are not a knowledge test

Cijferreeksen is number patterns, not arithmetic you were taught and forgot. Figurenreeksen has no words or numbers in it at all. Neither rewards revision of a syllabus; both reward having seen the format enough times that you recognise which kind of rule you are looking at within the first ten seconds.

The personality questionnaire has no right answers

Ixly says so on the report itself: a high or a low score is not good or bad. It measures 25 scales at once and they pull in different directions, so answering as the person you imagine a haulier wants produces a contradictory profile rather than a strong one. What does help is using the whole scale rather than sitting on the middle option, because a flat profile tells a recruiter nothing.

Sit it somewhere quiet

The item clock runs while you are away from the screen. An interruption is not a pause, it is a question given up.

Practise the exact tests

Our Ixly practice hub has all three ACT subtests, Cognitive Ability Pro, Stroomdiagrammen and the WPV personality questionnaire. Cijferreeksen is free.