Bac ST2S common mistakes
Bac ST2S · Understand the traps and how to avoid them.
Reciting a definition of santé or de santé publique without linking it to the concrete situation given in the document (for example a case of précarité énergétique), so the answer stays abstract and gets few points.
Candidates learn definitions by heart during revision and reuse them verbatim, because that feels safe. They do not practise applying the concept to a real case, so they never learn to select the relevant dimension of the definition.
What to do instead
For each notion in the programme (santé, bien-être, déterminants, inégalités), train on a short press article: underline the facts, then write two sentences naming which element of the definition each fact illustrates. In the exam, always start from the document and use the definition only to qualify it.
Confusing the different levels of prevention: describing a vaccination campaign as prévention tertiaire, or calling a screening programme primaire, and then justifying the wrong level.
The three levels are memorised as a list without the temporal logic (before the disease, at the asymptomatic stage, once complications exist). Under time pressure, candidates match on the word 'prévention' rather than on the moment of intervention.
What to do instead
Build a three-column table with the criterion 'moment in the history of the disease' and place ten real actions from the programme (port du préservatif, frottis, rééducation après AVC, dépistage organisé du cancer du sein). Justify each placement with the moment, not with the action's name.
Treating an indicator as a diagnosis: concluding that a département is unhealthy because its taux de mortalité is high, without checking the age structure or the size of the population concerned.
Indicators look like direct verdicts, and candidates are rarely asked to critique them. They also mix up taux bruts, taux standardisés and effectifs, and forget that a small effectif makes a rate unstable.
What to do instead
Before commenting on any figure, write three checks in the margin: what is counted (effectif or taux), in which population, over which period. Practise comparing two départements with different age structures to see why standardisation matters, and state the limit explicitly in the answer.
Describing an institution or a dispositif with the wrong scale: attributing a competence of l'État to la région, or presenting l'ARS as the body that votes health insurance spending.
The organisation of the French health and social system is taught as a list of acronyms (ARS, CNSA, HAS, CNAM, département) and candidates memorise the names without anchoring each one to its mission and its level (national, régional, départemental, communal).
What to do instead
Make a single reference table: institution, scale, main mission, one concrete example of a decision it takes. Test yourself by covering the mission column and retrieving it from the name, then the reverse. In the exam, name the scale explicitly in your sentence.
Answering a question about protection sociale with 'la Sécurité sociale rembourse tout' or ignoring the distinction between régime obligatoire, complémentaire and reste à charge.
The vocabulary of remboursement, base de remboursement, ticket modérateur and reste à charge is technical and often reduced to a vague idea that care is free in France. Candidates then reason on a false premise.
What to do instead
Work through one concrete care pathway (consultation, radiographie, lunettes) with the base de remboursement, the 70 % or 100 % rate, and the mutuelle. Compute the reste à charge yourself; the arithmetic forces the distinction to become real.
Presenting a handicap as a medical characteristic of the person only, omitting the role of the environment, and using outdated or stigmatising vocabulary in the copy.
The medical model of handicap is intuitive and still dominant in everyday language. Candidates reproduce the words they hear ('handicapé', 'souffre de', 'victime de') without knowing the shift introduced by the loi de 2005 and the notion of situation de handicap.
What to do instead
Learn one reference definition (handicap as the interaction between a deficiency and an environment) and apply it to a document: list what belongs to the person and what belongs to the environment (transport, logement, école). Rewrite five stigmatising sentences into respectful ones and keep that list for revision.
In the biology part, describing the mechanism of a pathology as a list of symptoms rather than explaining the causal chain (for example for le diabète de type 2, jumping from 'sucre' to 'complications' with no insulin resistance or hyperglycémie).
Symptoms are easier to memorise than mechanisms, and candidates run out of time on the physiology. They also confuse the role of the organ with the role of the hormone.
What to do instead
For each pathology in the programme, draw a five-step arrow diagram from the cause to the visible sign, and say it aloud. Then answer past questions using only the arrows, so the explanation is structured before the vocabulary is added.
Confusing the roles of the cell types and of the actors of the immune response, or describing the HIV cycle without distinguishing contamination, séropositivité and sida déclaré.
The vocabulary (lymphocyte T4, anticorps, séroconversion) is dense and close-sounding. Candidates learn it as labels and never place the terms on a timeline, so the stages collapse into one.
What to do instead
Draw a horizontal timeline for HIV and place each term at its date: contamination, séroconversion, phase asymptomatique, sida déclaré. For immunity, make a two-column table (immunité innée, immunité adaptative) with cells, delay and specificity. Reproduce both from memory weekly.
Writing the synthetic note or the argumentative answer as a personal opinion, without using the documents, without an explicit structure, and without concluding.
The written exercise rewards method, but candidates revise content only. They also fear that using the documents looks like copying, so they fall back on generalities and lose the points attached to the exploitation of the corpus.
What to do instead
Use a fixed plan: introduction naming the question and the documents, two or three paragraphs each built on one document and one notion from the programme, conclusion answering the question. Rehearse on a 20-minute timer and check afterwards that every paragraph cites a document.
Reading a graph or a table without stating the unit, the period and the source, and describing the curve ('it goes up') instead of calculating a variation or comparing two groups.
Candidates confuse description and interpretation, and skip the arithmetic because it feels like a maths task. The absence of a stated unit then makes the whole comment unverifiable.
What to do instead
Impose a three-sentence routine: what the document shows (nature, unit, period, source), what it says quantitatively (one calculated percentage or variation), what it means for the question. Practise on tables with two variables until the routine is automatic.