Research Variables

Research Variables

• a VARIABLE is a concept that stands for a variation within a class of objects or persons (Frenkel and Wallen, 1996)

• a VARIABLE is a characteristic or property that can take different values or attributes (Schutt,1999)

• Variables should be measurable and observable.

Examples of variables:

• age
• sex marital status
• income
• location of business

• revenue
• type of work
• number of meetings
• degree of malnutrition
• level of fertilizer
• type of crop
• size of land

Types of Variables:

Variables can be Classified as: dependent, independent, intervening, and antecedent variables

Dependent Variable: the dependent variable is the “assumed effect” of another variable.

Independent Variable: The Independent Variable is the “assumed cause” of a problem.

Intervening Variable : the factor that works “ between” the independent and dependent variable.

Sample problem: “ Knowledge of the Danger of Smoking, Attitude towards life, and Smoking Habits of Young Professionals"

Antecedent Variable: is a factor or characteristic which is found before (ante) the independent Variable.

Sample problem: “ Attitudes towards Land Reform and Acceptance of the Program Among Lowland Farmers of Northern Luzon"

Operational Definition of Variables

Some researchers cannot answer their research questions because they do not have clear measures of their variables. A variable must be operationally defines according to how it is used in the study so that it can properly be measured.

The operational definition gives a specific meaning to the variable. The definition clarifies how a variable or term be used and measures in the study. A variable must be defined in terms of events/ units of measurement that are observable by the senses ( Fisher, et.al.,1994). These events/units of measurement serve as indicators of the variables.

The operational definition of a variable specifies how a variable or a term is interpreted in the study and also sets the procedure for measuring variable. An operational definition of a variable in one study may differ from that employed in another study.

Study the examples below:

Please note that these definitions are not those that one will find in the dictionary. These definitions are define by the researcher him/herself to fit his/her study.

Establishing Categories of Variables

In some cases, a number, an amount or a sore may not be sufficient to represent a variable. To facilitate a description and analysis of data, categories of variables can be established. Each category should be operationally defined. The categories must be:

1. Mutually exclusive and
2. Exhaustive

MUTAULLY EXCLUSIVE CATEGORIES

Mutually exclusive categories do not overlap. Categories are mutually exclusive when a respondent cannot be assigned to more than one category. Some variables, like the knowledge scores, can be grouped and each group assigned a category, such as, “high level of knowledge, “ “average level of knowledge,” and “low level of knowledge. Each of these level categories should be operationally defined.

Example No.1

If for instance the researcher defines - level of knowledge about cancer- as “ the number of questions about cancer which a respondent answered correctly,” each level of knowledge may be assigned a range of scores.

Assuming that the possible total score is 20, the possible categories could be:

High level of knowledge = scores of 14 to 20

Average level of knowledge = scores of 7 to 13

Low level of knowledge = scores of 0 to 6

In addition, the score limits should be specified, like for purpose of interpretation like the mean score such as:

High level of knowledge = 13.6 - 20

Average level of knowledge = 6.6 - 13.5

Low level of knowledge = 0 - 6.5

Example No.2

For a variable like “residence” if its operational definition is “ geographical characteristics of the area where the respondents permanently reside,” the possible answer may be categorized as ‘rural” and “urban.” The meaning of “urban,” however, may be different in other studies. The operational deifinition depends on how the word is used in the study. The categories may be defined as:

Rural - refers to a place of residence which is located outside the geographical jurisdiction of a city or a town center.

Urban - refers to a place of residence which is located within the city proper or within the town proper of a municipality.

EXHAUSTIVE CATEGORIES

Categories are exhaustive if all the [possible responses are included among the options of responses. The answers given by every respondent can be assigned to a particular category. If a researcher is not sure about the exhaustiveness of the categories identified, he/she should include “ others,” which is the ‘catch all” category. Under this category, responses which cannot be assigned to any of the other categories can be classified.

Example

A list of categories like: Protestant, Catholic, Muslim, and Buddhist” for responses to a question on religion is not exhaustive because Mormon cannot be classified under any of the categories in the list. To correct this the item on the questionnaire should look like this:

What is your religion? Check one : ___Catholic ___Muslim ____Others, specify

___Protestant ___Buddhist

For instance,the variable “hobbies” is operationally defined as “ a type of activity a person engages in during leisure or free time.” The possible categories of this variable may be: “ singing,” “reading,” “painting,” “writing poem,” “sewing,” “others, specify.” What may not be classified under the five specific categories can be classified under “Others.” However, if during data analysis, the number of responses falling under the “others” exceed three, the responses must be specified and based on these an additional category can be added.

Operational Definition of Key Terms

There may be terms in the study (not variables) that have meaning different from their “dictionary meaning” or they take on different meanings, depending on situations or events. These terms must also be defined operationally to avoid misinterpretation. The definition depends on how the word is used and measures.

Examples:

1. Family planning user is any currently married woman aged 15 to 49 years old or married man aged 15 or older who has used a method to prevent or space pregnancy at least once during the last three months.

2. Coastal Barangay is a village or community which is located near the sea where fishing is the main activity of sresidents.

3.Merging is the absorption of one or more business firms by another existing firm which retains its identity and takes over the rights, privileges, franchises, and properties and assumes all the liabilities or obligations of the absorbed firm/s (Pudadera, 2002).

4. Interest rate represents the cost of borrowing money, expressed as a percent rate, for a given period of time.