Concours ENA Meknès common mistakes
Concours ENA Meknès · Understand the traps and how to avoid them.
In mathématiques, starting to write the solution before identifying which theorem or result the exercise is testing (e.g., attacking an integral without first checking convergence hypotheses for a theorem on series of functions), then producing a long calculation that goes nowhere.
Under time pressure candidates recognise a familiar-looking expression and jump to computation, skipping the 2–3 minutes of analysis that would reveal the intended method (comparison, integration by parts, telescoping, change of variable).
What to do instead
Impose a fixed 3-minute 'reading protocol' per exercise: write on scratch paper the objects involved, the hypotheses available, the target form, and the name of one theorem that connects them. Only start writing the solution once that line is filled. Practise on past papers by writing only these protocol lines, without solving, for 10 exercises in 40 minutes.
In algèbre, treating a matrix or linear map question as pure computation (row reduction) and never using the structural tools - rank–nullity, dimension formula, kernel/image, diagonalisability criteria, characteristic polynomial factoring - so a question that could be settled in two lines takes a page.
Linear algebra is taught with heavy computational drill, so candidates default to Gauss elimination even when the question asks about existence, uniqueness, or dimension, where structural arguments are far faster and safer.
What to do instead
Build a one-page 'structural reflex sheet': for each question verb (montrer que, en déduire, déterminer, discuter selon les valeurs de) list the structural tool it usually signals. Before any row reduction, ask: does the question need the actual solution or only its existence/dimension? If the latter, use rank arguments.
In probabilités, writing a probability as a bare number without defining the underlying probability space and events (e.g., answering 0.25 when the question asks for a conditional probability), and confusing P(A∩B) with P(A|B) or with P(A∪B).
Candidates memorise formulas (Bayes, total probability) as symbols and never practise translating a French sentence into a formal event, so the wrong formula is applied to the right numbers.
What to do instead
Force a written preamble for every probability question: name the experiment, the sample space, and define each event with a letter (A = 'la pièce provient de la machine 1'). Then write the question in symbols (calculer P(A|B)) before computing. Train with sentence-to-symbol translation drills only, no computation.
In physique, applying a formula without checking units, sign conventions and reference frames - for instance using energy conservation in a situation with non-conservative friction, or mixing radian and degree in an oscillation problem.
Formulas are learned as recipes detached from their derivation, so the validity conditions (conservative forces, small oscillations, ideal gas, quasi-static transformation) are never checked.
What to do instead
Adopt a three-line verification habit at the end of every physics answer: (1) dimensional analysis of the final expression, (2) explicit statement of the reference frame and axis orientation, (3) explicit statement of which hypotheses were used. If a hypothesis is violated, say so in the answer - examiners award that.
In chimie, balancing equations and doing stoichiometry on autopilot without identifying the limiting reagent, the actual reaction medium (acidic vs basic), or the state of the species, and reporting a yield or concentration computed from the wrong initial quantity.
Stoichiometry is drilled as arithmetic, so the chemical reasoning step - what actually reacts, in what medium, and what is in excess - is skipped, and the arithmetic is then applied to the wrong number of moles.
What to do instead
Use a fixed stoichiometry template: balanced equation with states, table of initial/change/final amounts in moles, explicit identification of the limiting reagent with justification, then conversion to the requested quantity. Never compute a concentration before the limiting reagent line is written.
In SVT/biologie, answering with vague generalities ('la plante a besoin d'eau pour pousser', 'les enzymes accélèrent les réactions') instead of naming the precise mechanism, structure or molecule the question targets, and describing experiments without stating the control and the conclusion drawn.
The subject is often revised by rereading course notes rather than by producing written answers, so candidates recognise vocabulary passively but cannot mobilise the precise term or the experimental logic under exam conditions.
What to do instead
Revise by active recall on diagrams: cover the labels, redraw and name each structure, then write a 5-line answer using at least three precise technical terms. For experimental questions, always write the protocol in the form 'témoin / test / variable mesurée / conclusion'.
In expression écrite et langue française, producing a dissertation or résumé that is grammatically clean but structurally empty: no explicit problématique, paragraphs that juxtapose ideas without transitions, and a conclusion that repeats the introduction instead of answering the question.
Candidates focus revision on content and vocabulary while the exam is graded heavily on the canonical structure (introduction with problématique and annonce de plan, two or three developed parts, conclusion answering the problématique), which is rarely rehearsed under timed conditions.
What to do instead
Drill the skeleton separately from the content: in 20 minutes, produce only the introduction (accroche, problématique, annonce de plan) and the conclusion for five different subjects. Then write full essays under a strict time budget (10 min plan, 1h30 rédaction, 10 min relecture) and have them checked against a structure grid, not just for spelling.
In culture générale et actualités agricoles et environnementales, citing no concrete facts - no figures, no named policies or institutions, no recent developments - and treating the agricultural and environmental theme as generic 'sustainable development' discourse.
Candidates revise from general knowledge summaries and neglect the specific Moroccan and Mediterranean agricultural context (water stress and irrigation policy, food sovereignty, agricultural cooperatives, rural development, climate adaptation), so answers lack the factual anchors examiners reward.
What to do instead
Maintain a dated one-page fact sheet per theme, each entry with a figure, a named institution or programme, and a source date; review it weekly and force yourself to insert at least two precise references into every practice essay on these themes. Update it with recent developments before the exam.
In anglais, translating French structures word for word (false friends, missing articles, wrong tense after 'since', 'actually' used for 'actuellement'), and answering comprehension questions by copying long passages instead of reformulating.
Reading and listening comprehension are practised passively, and written production is rarely corrected by anyone, so systematic interference errors from French persist unnoticed.
What to do instead
Keep a personal error log of your own recurring interference mistakes, written as French→English pairs, and review it before each practice session. For comprehension, impose a word limit on answers and require reformulation (no verbatim copying), then self-check against the log.
In the oral interview, delivering a memorised self-presentation that does not answer the actual question asked, and freezing or bluffing when a question probes motivation or a technical point; no questions are asked of the jury at the end.
The oral is prepared as a script rather than as a conversation, and candidates have rarely practised being interrupted or challenged, so they lose composure and revert to the memorised text.
What to do instead
Practise with a partner who deliberately interrupts, asks 'pourquoi cette école et pas une autre ?', and poses one technical follow-up; record yourself and check that every answer begins by addressing the question. Prepare three genuine questions about the programme and keep a short, honest formula ready for what you do not know.