The variable is a characteristic, which can assume varying or different values in successive individual cases. A research work usually contains at least two important variables: independent or causal and dependent or focus variables. A independent variable is that factor manipulated by the researcherthe researcher manipulates to ascertain its relationship to an observed phenomenon. In scientific research, the selection and measurement of variables constitute a significant task. Following this conception, the researcher reviewed the literature to widen this understanding of the natures and
scopes of the variables relevant to this research. At last, the researcher had selected 10 independent variables and one dependent variable. The causal variables were: age, education, family size, space for RTG, annual family income, annual income from house rent, RTG expereience, time spent for RTG, knowledge in RTG, attitude towards RTG. The dependent variable of this study was the, use of media for rooftop gardening related information by the gardeners. The methods and procedure in measuring variables of this study are presented in the following sections.
3.4.1 Measurement of independent variables
The ten characteristics of the gardeners mentioned above constitute the independent variables of this study. The following procedures were followed for measuring the causal variables.
3.4.1.1 Age
The age of the gardeners was measured in terms of actual years from their birth to the time of the interview, which was found on the basis of the verbal response of the people (Rashid, 2014). A score of one (1) was assigned for each year of one’s age. This variable appears in item number 1 in the interview schedule as presented in Appendix- I.
3.4.1.2 Education
The education was measured by assigning a score against successful years of schooling by a gardener. One score was given for passing each level in an educational institution (Rashid, 2014). For example, if a gardener passed the final examination of class five or equivalent examination, his/her education score has given five (5). Each gardener of cannot read & write given a score of zero (0). A person not knowing reading or writing but being able to sign only has given a score of 0.5. If a gardener did not go to school but took non-formal education, his educational status was determined as the equivalent to a formal school student. This variable appears in item number 2 in the interview schedule as presented in Appendix-I.
3.4.1.3 Family size
The family size of a respondent was determined by the total number of members in his/her family, including him/her, children and other dependents. The actual number made the scoring of family members expressed by the respondents. For example,
if a respondent had five members in his/her family, his/her score was given as 5.
This variable appears in item number 3 in the interview schedule as presented in Appendix-I.
3.4.1.4 Space for Rooftop Gardening
The surface area of roof (sq. ft.) garden refers to the total space of the roof on which his family carried out roof garden operation, the area being in terms of full benefit to the family. This variable appears in item number 4 in the interview schedule as presented in Appendix-I.
3.4.1.5 Annual Family Income
The annual family income refers to the total income earned in taka for doing job, service, business, agriculture etc. by the earning members of the family in the 12-month period . This variable appears in item number 5 in the interview schedule as presented in Appendix-I.
3.4.1.6 Annual Income from House Rent
The annual income from house rent refers to the total income (BDT) of the family by providing house rent in the 12-month period . This variable appears in item number 6 in the interview schedule as presented in Appendix-I.
3.4.1.7 Rooftop Gardening Experience
Experience in gardening of the gardener was determined by the total number of year involved in rooftop gardener. A score of one (1) was assigned for each year rooftop gardening. It was located in the item number 7 of the interview schedule as presented in Appendix-I.
3.4.1.8 Time Spent for Rooftop Gardening
Spending time for gardening of a respondent will be measured in terms of hours/week, options of the interview which will be found on the basis of the response. It was located in the item number 8 of the interview schedule as presented in Appendix-I.
3.4.1.9 Knowledge in Rooftop Gardening
The knowledge of a gardener was measured by asking 12 questions related to different components of rooftop gardening. It was measured assigning weight age 2 marks for each question. So, the total assigned scores for all the questions became 24. This
variable appears in the interview schedule in the item number 9 as presented in Appendix-l.
3.4.1.10 Attitude towards Rooftop Gardening
The attitude towards rooftop gardening was measured by asking 7 questions related to different components of rooftop gardening. The response was categorized into five extent scoring from 1 ( strongly disagree) to 5 ( strongly agree). This variable appears in the interview schedule in the item number 10 as presented in Appendix-l.
3.4.2 Measurement of the dependent variable
The dependent variable of the study is the extent of use of media for rooftop gardening related information by the gardeners. It was defined as one’s extent of exposure to different communication media related to rooftop gardening. The extent of use of media of a rooftop gardener was measured by computing media contact score on the basis of their nature of use of media with selected twelve media. Each rooftop gardener was asked to indicate his nature of use of media with five alternative responses, like Never (0), Rarely (1), Occasionally (2), Often (3) and Regularly (4) were assigned for those alternative responses, respectively. Logical frequencies were assigned for each of the five alternative nature of use of media. The extent of media use of the rooftop gardener was measured by adding the scores of twelve selected media. This variable appears in item number 11 in the interview schedule as presented in Appendix-I.