Variable Operationalization

Answer

Variable operationalization

Research involves measurement of various variables or concepts on research subjects. Variable operationalization refers to the methods a researcher uses to manipulate a variable, from abstract concepts to a form in which it can be measured and quantified (Gordis, 2013; Statistics Learning Center, 2011). In relates to the process undertaken that allows data on a given variable to be obtained.

Operationalization of variables follow the following procures:

• Identify the variable or concept
• Define the concept or variable to be measured
• Determine how the variable can be measured quantitatively
• Determine the method of obtaining the measure

DISCUSSION: How might one operationalize the following variables: diet, physical activity, health status, and social support? Be sure to note variable type (categorical versus continuous) and/or level (nominal, ordinal, interval, ratio).

Variable: Diet

Variable definition:  Diet refers to the food eaten by an individual during a given meal (Han & Dingemanse, 2017). Different foods have different nutritional values and can be grouped as high nutritious food or low nutritious food. Diet would be a categorical variable because then it is made up of categories, i.e high nutritious and low nutritious.

Measures of the variable: Diet can be measured as lists of all the foods eaten by an individual then determining the nutritional value of each.

Determine a method for obtaining the measure: Administer a diet assessment questionnaire. This tool has been shown to be valid and reliable for assessing nutritional value of diets (Lee, et al., 2014). Additionally one can develop a survey tool with questions for the respondent to list the foods eaten at a particular meal, say dinner on the previous day (Shiraishi, et. al., 2017). The listed foods can then be grouped based on their nutritional value, giving two mutually exclusive groups. The level of measurement for the variable would be nominal where each mutually exclusive group is assigned a numerical value. Another method would be administering a 24h- dietary recall and a single-item self-rated diet quality measure. further still, nutritional value of respondent diet can be measured by computing Healthy-Eating Index -2010 (HEI) scores from dietary recall (Adjoian, et. al., 2016).

Variable: Physical activity

Variable definition: physical activity refers to any bodily movement produced by skeletal muscles (Ainsworth & Buchholz, 2017)

Measures of the variable: As a categorical variable, physical activity can be measured using intensity of activity; such as no activity, mild activity, moderate activity and vigorous activity (Neil-Sztramko, et. al., 2017). Physical activity can also be measured as meeting national recommended cut off or not (Neil-Sztramko, et. al., 2017;Tandon, et al., 2016).

Method of obtaining the measure:  Can be measured using questionnaires, pedometers, and accelerometers.

Questionnaires: These can be researcher-administered have questions that ask the respondents about the amount of time per week they engage in physical activity. The variable is measured on an ordinal scale where depending on the amount of time indicated, responses are ranked from no activity to mild to moderate then vigorous. The variable can also be measured on a nominal scale by assigning one numerical value to the respondents who meet a recommended physical activity level and another number for those who do not meet the recommended level.

Pedometers: These can be worn by respondents to measure the level of physical activity on a given day, after which the measure is recorded on an ordinal scale (Ainsworth & Buchholz, 2017).

There are other tools than can measure intensity of physical activity as light to moderate physical. These tools include Actigraph, SenseWear Armband and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire (Almeida, et. al., 2016).

Variable: Health Status

Variable definition: Health status refers to the overall condition of health, of an individual or a population (Madans, 2014; Frempong-Ainguah, 2014). It can be a continuous variable measured as a score, obtained from measurement of certain parameters that indicate health status.

Measures of the variable: Health status can be measured as quality of life (Younsi & Chakroun, 2014; Madans, 2014)

Method of obtaining the measure: Health status can be measured using by using standardized and validated instruments such as EuroQol 5 dimensions (EQ-5D) instrument. This instrument can be administered as a cross-sectional household survey. The instrument has several questions that measure health status on a Likert scale. The responses are then weighted to obtain numerical measures, where higher scores indicate better health (Marufa, et. al., 2016)

Variable: Social support

Variable definition: Social support can be defined as the benefits available to society and individuals based on their membership in social networks (Carrillo & Riera, 2017). 

Measures of the variable: Social support can be measured by scale of intensity as a continuous type variable.

Method of obtaining the measure: The measure can be obtained through surveys with questions measuring social support on a Likert, scale where respondents select best options. One such survey that has been used before is the Personal Network Questionnaire (Esteban, et. al., 2016). The responses from the Likert Scale can then be weighted to get numerical measures. Higher scores indicate more social support. Another tool to measure social support is the Family Social Scale (Kondrat, et. al., 2014) which has questions measuring several dimensions of social support on a Likert scale, which can then be weighted into a scale.