My question is, in Engineering or Specialized Sciences which is the best translation for the concept Test: Ensayo o Prueba.

In Engineering, it is somehow common and standardized the concept Test (noun) to describe a procedure intended to establish the performance of something (ref. Oxford), as in the following applications:

  • ASTM, the ASTM American Society for Testing and Materials, and its body of standards,
  • Testing and Inspection, as per the ISO 9001 Quality Control and Quality Assurance clauses,
  • Non-Destructive | Destructive Testing, as a common concept.

But in Spanish, I have failed to find a proper word, and both "Prueba" and "Ensayo" are used more or less equally without any specific criteria:

  • For Mechanical and Structural Engineering, the word "Ensayo" (noun) is often used: Proof made to determine if something is works as intended (ref.Oxford): "Ensayo de Materiales", "Ensayo de Hormigón", "Ensayo de Barras de Acero", "Ensayo de Fuego". "Prueba" is seldom used for these applications.
  • For Electrical and Piping Engineering, the word "Prueba" (noun) is used instead: Action of prove somebody or something to know its qualities (ref. Oxford): "Prueba de Hermeticidad", "Prueba de Fuga" "Prueba Dieléctrica", "Prueba Punto a Punto". "Ensayo" is seldom use for these applications, conversely.
  • Finally, in General and for Quality Engineering, the words "Ensayo" and "Prueba" are both equally used, and the general concepts "Pruebas No Destructivas" y "Ensayos No Destructivos" are both equally used.

Google Searches tends to give more results for "Prueba" than "Ensayo", but this could be attributed the word "Ensayo" is less common and specific in sense in Spanish, meanwhile "Prueba" has a broader sense.

My impression is that in Engineering, the concept "Ensayo" involves a more elaborated setup, than the concept "Prueba" which involves something more broader and simple, like a measurement with an instrument.

What tricks me is, according the setup or even the Engineering Discipline, one should choose which one or another. So if you are mixing disciplines, you should be ready to use "Ensayo de Resistencia" and "Prueba de Resistencia" for referring to similar setups.

  • 2
    For what it is worth in medicine a clinical trial is ensayo clínico which fits with the meanings you suggest as it is a complex procedure (with rules about its conduct) which tests a medical product or procedure. I know you asked specifically about engineering but other fields may give you an insight.
    – mdewey
    Oct 2, 2022 at 10:03
  • 3
    I agree that "ensayo" is more technical. In English we can also find "trial" in that context. "Prueba de resistencia" sounds like a test to check sb's physical resistance.
    – Gustavson
    Oct 2, 2022 at 12:50

2 Answers 2


The word ensayo applies to more technical and involved tests, for example in medicine the Spanish for clinical trial is ensayo clínico. Such a trials will involve a large number of steps, preparing a protocol, obtaining permission, registering the trial, executing the trial, storing the data securely, pre-specifying an analysis plan, locking the databases, analysing the data. The whole thing takes years.

By contrast in the same field prueba is used for simpler procedures. For example the Pap Test is in Spanish prueba de Pap. Here the health care professional takes the sample from the woman, sends it off to the lab and gets the result. So a much simpler procedure.

  • 1
    +1 Although your explanation refers to medicine and not to engineering, I find it to be very clear as well as applicable to many, if not all technical fields.
    – Gustavson
    Oct 3, 2022 at 12:49
  • 1
    In the oil and gas industry, we always speak about "ensayos de pozos", not "pruebas de pozos", to refer to well tests.
    – Gustavson
    Oct 3, 2022 at 15:05
  • prueba is always a test or in food (probar la comida, to taste the food) or clothes, try on the clothes, etc. ensayo can be a trial or test. It depends on the subject matter.
    – Lambie
    Oct 3, 2022 at 17:15
  • Granted. I agree with using "Ensayo" in more technical frameworks, leaving "Prueba" for more simple setups.
    – Brethlosze
    Oct 4, 2022 at 21:04

The best authoritative source here is really the RAE:

ensayo Del lat. tardío exagium 'acto de pesar'.

  1. m. Acción y efecto de ensayar. [rehearse]

  2. m. Escrito en prosa en el cual un autor desarrolla sus ideas sobre un tema determinado con carácter y estilo personales. [essay writing]

  3. m. Género literario al que pertenece el ensayo.

  4. m. Operación por la cual se averigua el metal o metales que contiene la mena, y la proporción en que cada uno está con el peso de ella. [test as in stress test]

  5. m. Análisis de la moneda para descubrir su ley.


  1. f. Acción y efecto de probar.

  2. f. Razón, argumento, instrumento u otro medio con que se pretende mostrar y hacer patente la verdad o falsedad de algo.

  3. f. Indicio, señal o muestra que se da de algo.

  4. f. Ensayo o experimento que se hace de algo, para saber cómo resultará en su forma definitiva. [trial or test or experiment]

  5. f. Operación matemática que se ejecuta para comprobar que otra ya hecha es correcta. [proof]

  6. f. Análisis médico. [test, like blood test]

  7. f. Muestra, cantidad pequeña de un alimento destinada a examinar su calidad. [sample]

  8. f. Examen que se hace para demostrar o comprobar los conocimientos o aptitudes de alguien. [exam or test, in education]

  9. f. En algunos deportes, competición.

  10. f. Muestra del grabado y de la fotografía.

  11. f. Reproducción en papel de una imagen fotográfica.


It's just best to go to a good source.

Clinical trial: ensayo clínico [clinical trial] Sublema de ensayo Adm. Estudio clínico de una estrategia terapéutica determinada que no forma parte de la práctica clínica habitual. Reglamento (UE) 536/2014, del PE y del Consejo, de 16-IV-2014, sobre los ensayos clínicos de medicamentos de uso humano. Real Decreto 1090/2015, de 4 de diciembre, por el que se regulan los ensayos clínicos con medicamentos, los comités de ética de la investigación con medicamentos y el registro español de estudios clínicos.

Engineering: non-destructive testing
ensayo non-destructivo
¿Qué es un Ensayo No Destructivo? Los ensayo no destructivo son aquellos ensayos que no alteran la forma ni las propiedades de un objeto. No producen ningún tipo de daño en él o e daño es prácticamente imperceptible. Este tipo de ensayos sirven para estudiar propiedades físicas, químicas o mecánicas de algunos materiales.

En SCI realizamos múltiples END de diferentes tipos. Aquí queremos explicaros cuáles son los principales que os podeos ofrecer:


"Ensayo de Materiales",
"Ensayo de Hormigón",
"Ensayo de Barras de Acero", "Ensayo de Fuego".

Material testing
Concrete testing [for example: concrete slump testing]
Steel bar testing
Fire testing Those are all tests, not "proofs".

This: Action of prove somebody or something to know its qualities. is not accurate English.

Accurate here would be: Action of testing somebody or something to know its/their qualities

  • 1
    What exactly is the downvote even for?
    – Lambie
    Oct 3, 2022 at 17:02
  • I upvoted :). I tend to favor the "Ensayo word", since the word "Prueba" seems to be used in more informal frameworks...
    – Brethlosze
    Oct 4, 2022 at 21:03
  • @Brethlosze The difference is not about formality. It is about field and subject matter.
    – Lambie
    Oct 5, 2022 at 14:55

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