TestAS common mistakes
TestAS · Understand the traps and how to avoid them.
Solving the Figurale Gruppen (figure matrices) items by searching for a single rule that explains every cell, instead of testing one attribute at a time (count, position, orientation, shading, symmetry).
Candidates treat the 3x3 grid as one puzzle and freeze when no single 'story' fits; TestAS figure items usually combine two or three independent rules, one per row or column, so a holistic search burns the roughly one-minute budget per item.
What to do instead
Train a fixed checklist: number of elements, type of element, position/rotation, fill/line style, size, symmetry. For each item, write the rule you believe applies to rows and verify it against all three rows before choosing; if one row breaks it, discard and test the next attribute. Practise with a timer at 60–75 seconds per item until the checklist is automatic.
Spending too long on individual items in the speeded subtests (Figuren zusammensetzen, Zahlenreihen, Rechenoperationen) and leaving 10–20 items blank at the end.
The General aptitude module is scored on correct answers within a fixed time, and candidates over-invest in the first hard item they meet because there is no penalty for wrong answers and no obvious signal to move on.
What to do instead
Adopt a hard skip rule: if no clear solution path appears within about 45–60 seconds, mark and move on, return only if time remains. Do timed full-length practice runs so you know your natural pace, and rehearse guessing the remaining items in the last 30 seconds, since blank answers score zero.
Treating Zahlenreihen (number sequences) as free-form arithmetic guessing, trying random operations on the first two terms rather than classifying the sequence type first.
Schools teach sequences as arithmetic or geometric only, so candidates miss alternating sequences, second-order differences, interleaved sequences, and digit-based rules, and then apply the wrong operation repeatedly.
What to do instead
Classify before computing: check constant difference, then constant ratio, then differences of differences, then two interleaved sequences (odd/even positions), then digit or square/cube patterns. Write the differences under the series; if they grow, test a multiplicative or second-order rule. Drill 5–10 sequences per session and label each with its rule type.
In Rechenoperationen (arithmetic operators), solving each equation fully instead of using the answer options and the structure of the expression to eliminate choices.
Candidates default to school-style full computation, which is slow and error-prone under time pressure, and they ignore that the distractors are built around typical sign and precedence errors.
What to do instead
Practise estimation and last-digit checks, substitute answer options back into the equation, and exploit symmetries such as equal terms cancelling. Rehearse the order of operations with fractions, powers, and roots, since most errors come from precedence and sign handling rather than the arithmetic itself.
Reading a text in the Sprachverständnis section word by word and answering from general knowledge or personal opinion instead of locating the sentence that decides the question.
Candidates transfer a school reading habit (read everything, then answer) to a format where four statements must be judged solely against the text, and where plausible-sounding statements are deliberately not supported by it.
What to do instead
Skim the questions first, then scan for the relevant passage and match it literally. For each statement decide: explicitly supported, explicitly contradicted, or not stated - and treat 'not stated' as a distinct category. Practise with texts in the exam language and justify every answer with a quoted line.
In the subject module Ingenieurwissenschaften, setting up the full formula for a mechanics or electrical item instead of using proportional reasoning and unit checks to reach the answer.
University preparation emphasises derivation, but TestAS engineering items are designed for fast estimation; candidates lose minutes on algebra and make arithmetic slips in the final step.
What to do instead
Before computing, ask what quantity is asked and whether the answer scales linearly or quadratically with the given values. Check the unit of each answer option to eliminate wrong dimensions, and use limiting cases (zero, very large) to discard impossible options. Reserve full derivation only when no option can be eliminated.
In Wirtschaftswissenschaften items, confusing percentage points with percent, and applying markup and discount successively in the wrong base.
Everyday language blurs 'percent' and 'percentage points', and candidates compute a 20% increase followed by a 20% decrease as returning to the original value, which is exactly what the distractors assume.
What to do instead
Always write the base next to the percentage (e.g. 20% of 150, not 20% of 180). For successive changes, multiply factors: 1.2 x 0.8 = 0.96, a 4% net decrease. Drill elasticity, break-even, and compound-growth items until the base is the first thing you identify.
In the MINT subject module, misreading the axis, scale, or unit in a table or graph and answering from the visual impression rather than the plotted values.
Graphs in the test often use non-zero origins, logarithmic scales, or units differing from the question (kJ vs J, mA vs A), and the visually 'obvious' answer is usually a designed distractor.
What to do instead
Read the axis labels, units, and legend before looking at the data, and note the origin value. Convert all quantities to SI units in a scratch line before computing, and sanity-check the result against the order of magnitude implied by the graph.
In the humanities subject module, answering questions about a short source text or a diagram from prior knowledge of the historical period or author rather than from the material given.
Candidates with strong subject background trust memory over the passage, but the items are constructed so that the correct answer follows only from the supplied text or image, and prior knowledge often points to a distractor.
What to do instead
Force yourself to cite the line, phrase, or visual detail that supports your choice; if you cannot, the answer is probably wrong. Separate 'what the source says' from 'what I know about the topic', and practise with unfamiliar periods or authors so memory cannot substitute for reading.
Ignoring the language of instruction and the module choice rules, then preparing only one subject module or practising exclusively in the wrong test language.
TestAS is delivered in German or English depending on the test centre and registration, and the subject module must be chosen to match the intended degree field; candidates discover this late and lose preparation time or sit a module that does not fit their application.
What to do instead
Confirm on your registration which test language and which subject module apply to your target programme, and do all timed practice in that language and module. If you are unsure between two modules, sit one full timed mock of each and choose based on score and comfort, not on assumed difficulty.