2.Reliability: The test must produce consistent and coherent results, ensuring the stability of the measurement.

3.Validity: The test must precisely and accurately measure what it is intended to measure.

4.Practicality: Easy to manage and grade.

Motor Area
Instruments in the motor domain evaluate both fine and gross motor skills during the early years. They measure a child’s ability to crawl, walk, manipulate objects, and coordinate small hand movements.

Language Area
Language development is a central aspect of early stimulation, and assessment instruments in this area examine both receptive and expressive communication. They help determine how children understand and use sounds, words, and sentences.

Socioemotional Area
In early childhood, socioemotional development involves building relationships, regulating emotions, and developing social skills. Instruments in this area evaluate behavior, attachment, and emotional well-being.

• Name of the Instrument: Bayley Scales of Infant and Toddler Development, Third Edition (Bayley III)

• Age Range: From 1 month to 42 months; approximately 3 years and 6 months.

• Description of the Test:
  The Bayley-III is one of the most widely used tools to assess early childhood development. In the cognitive scale, it evaluates how infants and toddlers explore their environment, solve simple problems, remember objects, and respond to new situations. Tasks include looking for hidden objects, recognizing shapes, and completing simple puzzles. It helps detect developmental delays at an early stage.

• Example of Early Stimulation / Child Psychology Application:
  If a child shows difficulty in remembering where an object is hidden, an early stimulation activity might include object permanence games, such as hiding a toy under a cloth and encouraging the child to find it. This strengthens memory, problem-solving, and attention—core aspects of cognitive development.

• Name of the Instrument: Preschool Language Scale, Fifth Edition (PLS-5)

• Age Range: From birth to 7 years 11 months.

• Description of the Test:
  The PLS-5 is designed to evaluate both receptive and expressive language skills in infants and young children. For younger children, tasks may include responding to sounds, identifying objects, or following simple commands. For older toddlers, tasks expand to naming pictures, using words to describe actions, and forming sentences. This instrument is widely used to identify delays in speech and language development.

• Example of Early Stimulation / Child Psychology Application:
  If a toddler struggles with expressive language, an early stimulation activity may include naming familiar objects during play and encouraging the child to repeat. Singing simple songs, using picture books, and engaging in turn taking conversations also help strengthen vocabulary and communication skills.

https://www.redalyc.org/pdf/5826/582663829013.pdf

Cuevas (2012), Orígenes y Evolución de la Atención Temprana. Una Perspectiva Histórica de la Génesis de la Atención Temprana en Nuestro País. Agentes Contextos y Procesos Psicología Educativa. Revista de los Psicólogos de la Educación, vol. 18, núm. 2

https://www.redalyc.org/pdf/6137/613765470003.pdf

Lázaro (2021), La estimulación temprana para el desarrollo infantil, Universidad de Oriente, Cuba, vol. 21

https://www.redalyc.org/journal/4757/475769312006/html/