Analysis of variables that are not directly observable: influence on decision-making during the research process

Abstract

A dimensão da amostra, o tipo de variá-veis, o seu formato de medida, a construção dos instrumentos de recolha de dados válidos e fiáveis, são aspectos a ter em consideração no processo de investigação. No âmbito das ciências sociais, da saúde e especificamente na área de enfermagem, os instrumentos de recolha de dados são muitas vezes compostos por variáveis componentes ou indicadores que dão origem a variáveis latentes ou não observáveis diretamente, daí a importância da decisão relativa à forma como são medidas (escala ordinal, Likert ou de tipo Likert). As escalas psicométricas são exemplos de instrumentos, pelo tipo de variáveis que as integram, que podem trazer problemas de medida e de análise estatística (testes paramétricos versus não paramétricos). Assim o investigador quando usa estas variáveis deve respeitar alguns pressupostos baseados em estudos de simulação ou em recomendações fundamentadas na evidência científica, de forma a tomar a melhor decisão.

Adherence to best care practices in normal birth: construction and validation of an instrument

“…We observed the theoretical rating scales with five grades, the middle was neutro (11) . After applying a representative sample as a rule of thumb, the aim was to build scores through the sum of the items valuations and create additional interval variables (11) .…”

“…For example, to the item "I promote the skin to skin contact between mother and newborn, during the first half hour of birth" the higher the score, the higher the adherence but for items that have reverse score (that is, "routine episiotomy is held in this service") the higher score the worst is adherence. The instrument has 22 items with reverse scores (1,5,6,7,8,11,14,17,18,27,28,29,30, 31, 32, 33, 39, 41, 44, 48, 49, 50).…”

“…Adherence to best practice here was treated as construct being measured (latent variable) through indirect observation of its manifestations in the daily health work process in the context of the healthcare network to pregnancy and childbirth (11) . These manifestations are the items (operational concepts) of adherence, which constitute attitudes, behaviors, anxieties, opinions on health, physical and psychological well-being of women informed through a process of selfdescription or observer assessment.…”

Interactive breastfeeding scale: proposition based on the middle-range theory of nursing

“…Among them, the most known are the Likert scales, the Thurstone scale, the Guttman scale and the Phrase Completion Scale. 9,10 According to Pasquali,8 psychometry seeks to clarify the meaning of the responses attributed by people to a group of tasks, typically called items. In sciences, it is common to use measuring instruments to measure the object of study.…”

“…Each item receives a value, and based on the weighted average of the items, as agreed, we measure the response. 9,12 In 1932, Rensis Likert created a five-point scale. The study of this author advocates the construction of scales that allow people from different points of view to respond to the questionnaire.…”