Identify variable and measurement of scale


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Identify variable and measurement of scale

  1. 1. by – Janisha Gandhi
  2. 2.  Variable Types of Variable Dependent Variable Independent Variable Control Variable Measurement of scale Types of Measurement of Scale Nominal Scale Ordinal Scale Interval Scale Ratio Scale
  3. 3.  A variable is any entity that can take on different values across individuals and time. A variables refer to factors or conditions that can change during the course of an experiment. Variables in research Variables are things that we measure, control, or manipulate in research.
  4. 4. For examples, Age can be considered a variable because age can take different values for different people or for the same person at different times. Similarly, country can be considered a variable because a persons country can be assigned a value
  5. 5.  In the question,"How fast is a car going that travels 10 km in one hour?" The variables are: 10 km in distance 1 hour of time
  6. 6. Dependent VariableIndependent VariableControl Variable
  7. 7.  An independent variable is the variable that the researchers systematically manipulate in the experiment. An independent variable is measured, manipulated, or selected by the experimenter to determine its relationship to an observed phenomenon.
  8. 8. For example, if a researcher has two groups of people watch either a happy film or a sad film before giving an IQ test, the IV is the mood of the participants. if scientists are studying how putting salt in cold water affects how long it takes to boil water, the presence of salt is the independent variable.
  9. 9.  The dependent variable is a variable that changes as the result of changing the independent variable. A dependent variable is the factor which is observed and measured to determine the effect of the independent variable, that is, that factor that appears, disappears, or varies as the experimenter introduces, removes, or varies the independent variable.
  10. 10. For example, IQ was hypothesized to depend on the mood of the participants. If water boils faster when salt is added to it, then the time water takes to boil is the dependent variable.
  11. 11.  An independent variable, sometimes called an experimental or predictor variable, is a variable that is being manipulated in an experiment in order to observe the effect on a dependent variable, sometimes called an outcome variable
  12. 12.  Height depends upon on age, hence height is a dependent variable and age is independent. Height is also depends on sex, then height is dependent and age and sex are independent. If I drink Mountain Dew before bed, then I will not sleep very much. IV: Drinking Mountain Dew DV: the amount of sleep
  13. 13.  Imagine that a tutor asks 100 students to complete a maths test. The tutor wants to know why some students perform better than others. Whilst the tutor does not know the answer to this, she thinks that it might be because of two reasons: (1) some students spend more time revising for their test; and (2) some students are naturally more intelligent than others. As such, the tutor decides to investigate the effect of revision time and intelligence on the test performance of the 100 students. The dependent and independent variables for the study are:
  14. 14.  Dependent Variable: Test Mark (measured from 0 to 100) Independent Variables: Revision time (measured in hours) Intelligence (measured using IQ score)
  15. 15.  Control variables, then, are those that the researcher has chosen to keep constant, neutralize, or otherwise eliminate so that they will not have an effect on the study.
  16. 16.  if scientists are studying how putting salt in cold water affects how long it takes to boil water, the presence of salt is the independent variable. If water boils faster when salt is added to it, then the time water takes to boil is the dependent variable Control variables , the amount of water used, size of the burners and the temperature of the heating element.
  17. 17.  Scale may be defined as any series of items that are arranged progressively according to the value and magnitude, into which an item can be placed according to its qualification. Scale of measurement refers to how variables are measured.
  18. 18.  A scale is simply a system of assigning number symbols to events in order to label them for identification/classification. It classifies persons or objects into two or more categories. Members of a category have a common set of characteristics, and each member may only belong to one category. Yes/no scale in research activities.
  19. 19. Which of the following food items do you tend to buy at least onceper month? (Please tick)Okra Palm Oil Milled RicePeppers Prawns Pasteurized milk
  20. 20.  A Scale that arranges objects/alternatives according to their magnitude in an ordered relationship. For example, if a researcher asked farmers to rank 5 brands of pesticide in order of preference he/she might obtain responses like those in table.
  21. 21. An example of an ordinal scale used to determine farmerspreferences among 5 brands of pesticide. Order of Brand preference 1 Rambo 2 R.I.P. 3 Killalot 4 D.O.A. 5 Bugdeath
  22. 22.  A scale the only arranges objects/alternatives according to their magnitudes but also distinguishes this ordered arrangement in units of equal intervals. Standard survey rating scale. Used for ranking and measuring the interval between two numbers.
  23. 23. Please indicate your views on Balkan Olives by scoring them on a scale of 5 down to 1 (i.e. 5= Excellent; 1= Poor) on each of the criteria listedBalkan Circle the appropriate score on eachOlives are: lineSucculenc 5 4 3 2 1eFresh 5 4 3 2 1tastingFree of 5 4 3 2 1skinblemishGood value 5 4 3 2 1Attractively 5 4 3 2 1packaged
  24. 24.  The highest level of measurement is a ratio scale. This has the properties of an interval scale together with a fixed origin or zero point. Example: Income, age, number of children, or cost of housing. Your income could be zero; you might not have children; your rent could be free.
  25. 25.  Examples of variables which are ratio scaled include weights, lengths and times. Ratio scales permit the researcher to compare both differences in scores and the relative magnitude of scores. For instance the difference between 5 and 10 minutes is the same as that between 10 and 15 minutes, and 10 minutes is twice as long as 5 minutes.
  26. 26. THANK YOU