Formulating Variables

1. Formulating Variables Week 5 Dept. RS & GIS Institute of space technology

2. Difference between a concept and a variable? • Main difference is measurability • Concepts are mental images/perceptions and their meanings vary person to person • May or may be measurable • Sorrow • Tasty • Satisfaction

3. Value Judgments? • Outcomes of our study are excellent • This report is wonderful • We have developed a good model • The results shows that this is an outstanding research project • Relationship between these two variables is very weak. • All other studies are inferior than this work

4. Such Judgments without sound basis is not acceptable in research!!! • A measuring mechanism is required • Concepts should be converted into variables for measurements • Any concept that is capable of measurement is a variable….can take on different values

5. What is a variable? • a concept that can be measured • a symbol to which numerals or values are attached • or simply, a variable is something that varies

6. Examples of concepts & Variables Concepts Variables Effectiveness Satisfaction Water Quality Excellent Rich enrollments in a program Employees complaints Bacteria count GPA Income

7. It is needed to operationalize concepts into indicators and variables with the goal of limiting the extent of variation in respondents’ understanding

8. Converting concepts into variables • Identify indicators – criteria • Convert indicators into variables • Choices of indicators may vary with the researcher • There should be a logical link between indicators and their concept

9. Table 5.2 • Example 1: Rich • Find indicators for wealth • Example 2: High academic achievement • Indicators??? Concepts Indicators Variables

10. Types of variable • From the view point of • causal relationship • study design • unit of measurements

11. From view point of causal relationship • Change variables or Independent variable • Responsible for bringing about change in a phenomenon, situation and circumstance • Outcome or Dependent variable • Effects, impacts or consequences of a change variable • Extraneous (influencing) • Affect change in dependent variable • Intervening (linking) • Establish a relationship/link between independent and dependent variables

12. Independent variable • on which you have a control Dependent variable • variation in the dependent variable depends on the variation in the independent variable Precipitation Runoff Sunny days in London Revenue Generated

14. Extraneous • May increase or decrease the magnitude or strength of a relationship between DV and IV variables • Can not be controlled

15. Intervening • Completes the relationship between cause-and-effect variables Sunny days in London Tourism activities Revenue Generated

16. From view point of study design • Active variables • Variables that can be manipulated, changed or controlled • Attribute variables • Can not be manipulated, changed or controlled and that reflect the characteristics of the study population • Age • Gender • Education • Income • motivation • Etc.

17. From view point of unit of measurement • Categorical/Continuous • Qualitative/Quantitative • Very little difference between categorical and qualitative and between continuous and quantitative

18. Measurement Scale • Types: • Nominal • Ordinal • Interval • Ratio • Any concept that can be measured on these scales is called a variable • Degree of precision in measuring a variable varies from one measurement scale to another Categorical and Qualitative Continuous and Quantitative

20. Nominal • Each group has a characteristics which is common to all classified within that group • Sequence of listing of the subgroups is irrelevant since no relationship between subgroups • Examples: • Gender: Male/female • Religion: Islam/Christianity/Hindu • Tree, house, car, name etc.

21. Ordinal • has characteristics of a nominal scale PLUS subgroups have relationship to one another • arranged in ascending or descending order • Ranked according to magnitude but actual magnitude is not quantifiable • distance between categories is not equal, since magnitude is not quantifiable • Example: • Income • Above average • Average • Below average • $ 0 – 1,999 • $2,000-2,900 • +$3,000 • Age groups • Infant • Young • Old

22. Interval • as ordinal plus an arbitrary starting and ending point • Example: • 0°C is the arbitrary start point with 100 °C the arbitrary end point • The gap is divided into 100 equal spaced intervals • Not an absolute measurement –can’t say 60°C is twice as hot as 30°C • Cannot perform math calc on each reading, but can do so on differences in readings: 10°C hotter today vs. yesterday

23. Ratio • All properties of an interval scale plus a fixed starting point e.g. a zero point • Examples: • Height in cm • Flow volume • Provides an absolute measurement – 60 cm is twice as long as 30 cm • Difference between intervals is the same and is measured from a zero starting point, therefore can be used for mathematical operations

24. Table 5.4

26. Why it is important to know how a variable is measured? • Defines what the type of analysis? • Type of applicable statistical procedures? • The way the data can be interpreted? • How the outcomes can be communicated? • Style of your report entirely depends on the way variables are measured – way a question has been asked and its response has been recorded

28. Week 5: Supplementary Notes

29. Research Objectives • what do you want to achieve from your research? • closely related to the research problem • state your objectives in clear and concise manner • break down into smaller, logically connected parts

30. Why objectives are needed? • The formulation of objectives will help you to: • Focus the study • narrowing it down to essentials • Avoid collection of unnecessary data • data which are not strictly necessary for understanding and solving the problem you have identified • Organize the study in clearly defined parts or phases

31. Keep in mind that when the project is evaluated • Results will be compared to the objectives – no clear objectives no evaluation!!!!!

32. How you state your objectives? • Cover all aspects of the problem • Realistic • clearly phrased in operational terms • specifying exactly what you are going to do, where, and for what purpose • Use action verbs - specific enough to be evaluated • Examples of action verbs are: to determine, to compare, to verify, to calculate, to describe, and to establish. • Avoid the use of vague non-action verbs • Examples of non-action verbs: to appreciate, to understand, or to study • For action/non-action verbs look at http://www.ctu.edu.vn/guidelines/scientific/thesis/part1/1.4W.htm

33. How to formulate? • Brainstorm about your research objectives; • Identify your research objectives; • Generate general and specific actions; • Formulate general and specific research objectives; • Do a self-check. • For your help - please look at http://www.ctu.edu.vn/guidelines/scientific/thesis/part1/1.4W.htm

34. Abstract • What does your study or research paper present • What was the objective(s) of conducting the study • Brief description of your data (what, when, how) • Discuss your model/methodology • Conclude your work • Avoid; long sentences, spelling and grammatical mistakes, references, footnotes