Measurement of variable& scaling


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Measurement of variable& scaling

  1. 1. How are variables measured?Office deskDemographic dataAbsenteeism (decision making when who is to be fired?)Blood pressure, height, weight.Perception, feelings and attitude (subjective)
  2. 2. Operational Definition or Operationalizingthe ConceptWay of measuring abstract things to observable characteristics and behaviour.Concept: ThirstyDrink plenty of fluidsTo determine the thirst levels of each individuals by measuring the quantity of fluid they consume to quench their thirst
  3. 3. Mc Cleland’s theoryNeed of AchievementNeed of PowerNeed of Affiliation Need of Achievement Measure?
  4. 4. What behavioral dimension is observedwithin people driven by high motivation?1. Work round the clock or driven by work.2. Unwillingness to relax3. Work on their own4. Challenging job but not too challenging where probability of success is low5. Progress by getting feedback
  5. 5. Dimension 1: Work round the clockWorking all the time( number of hours worker in a day)Persevere even in face of some setbacks( nos. of setbacks experienced in task)Reluctance to take time off ( how frequently time off and for what reasons)
  6. 6. Dimension 2: Unwillingness to relaxHow often you think about work when you are away from workplace?What are your hobbies?How do you spend your time when you are away from the workplace? Continuum of who relax very well to who relax very little
  7. 7. Dimension 3: Work on their own No patience with ineffective people and are reluctant to work with others Impatience with ineffectiveness
  8. 8. Dimension 4: Challenging job but nottoo challengingRoutine or stereotyped job description and other calling for gradations of challenge built into them Those to opt for medium degree of challenge would have high achievement orientation then lower or higher ones
  9. 9. Dimension 5: Progress by getting feedbackLike feedback from superiors and even subordinatesAppreciate both positive and negative by keeping a track on how often individuals seek feedback from other during a certain period of time- say a month or more. Continuum of extensive feedback to no feedback
  10. 10. 1. To what extent you push yourself to get the work done?2. How difficult do you find it to continue in face of failures or discouraging results?3. How often do you neglect personal matters because you are preoccupied by your job?4. How frequently you think about ur job when away?5. To what extent you engage in hobbies?6. How disappointed you feel on not reaching goals you had set for yourself?7. How much do you concentrate on job?8. How annoyed you get when you make mistakes?9. To what extent u refer to work with a friendly but incompetent to one who’s competent?10. To what extent u prefer to work yourself?11. To what extent you prefer a job that is difficult but challenging than easy to routine?12. To what degree you prefer extremely difficult assignment to easy one?13. During 3 months, how often have you sought for feedback from superiors?14. During 3 months, how often have you sought for feedback from coworkers?15. How often within 3 months you have checked with your subordinates that what you are doing in not getting in their way of efficient performance/16. To what extent would it frustrate you if people did not give you feedback on how you are progressing?
  11. 11. What is operational definition is notNot reasons, antecedents, consequences and correlatesIt describes observable characteristicsExercise:Operationalize concept of Learning and Stress
  12. 12. Scalingthe process or result ofobserving an event or objectin order to determine its extent or quantityby comparison with a known unit andthen assigning numbers or any other symbols to characteristic or featureaccording to some prespecified formal rules.
  13. 13. There are four primary scales ofmeasurement areNominal (or categorical) scaleOrdinal scaleInterval scaleRatio scale
  14. 14. Nominal Scaledoes not express any values or relationships between variablesthe only mathematical or statistical operation that can be performed on nominal scales is a frequency run or countmost of the demographic information collected is in the form of nominal scalescategories are mutually exclusive and exhaustive
  15. 15. ExampleAmericanAustralianChineseGermanIndianEvery respondent has to fit any oneExample 1Gender – male or femaleExample 2Do you use Fair and Lovely soap?– yes or noExample 3Are you undergraduate, graduate or post graduate?
  16. 16. ExerciseSuggest two variables that would be natural candidates for nominal scales and set up mutually exclusive or collectively exhaustive categories for each.
  17. 17. Ordinal Scale categories have a logical or ordered relationship to each other (rank-orders the categories in a meaningful way) permit the measurement of degrees of difference, but not the specific amount of difference. only possible to determine whether an object or individual has more or less or equal amount of characteristic in comparison to any other – but NOT what amount of this characteristic
  18. 18. ExampleExample - Let there be 3 students A, B and C who respectively received 10, 12 and 20 marks in a test.The ranks would be – A – 1st B – 2nd C – 3rdThe quantitative (numerical) difference between 1 and 2 is the same as that between 2 and 3.But the difference between the ranks, 1st and 2nd is NOT the same as that between 2nd and 3rd.
  19. 19. ExerciseDevelop an ordinal scale for consumer preferences for different brands of beer
  20. 20. Interval Scalenumbers are used to rate and assess objects so that numerically equal distances on the scale represent equal distances in the characteristic being measureddistance between adjacent points on the scale is equalIt helps to compute mean and standard deviationno true zero in this scale
  21. 21. ExampleLet there be 4 students A, B, C and D who respectively received 4, 10, 16 and 20 marks in a test.Is D doubly brilliant than B?Is A’s brilliance a quarter that of C’s?The quantitative (numerical) difference between A’s marks and B’s is the same as that between B’s and C’sThe quantitative (numerical) difference between C’s marks and D’s is thrice that between B’s and C’s.
  22. 22. ExerciseDevelop Achievement motivation on the interval scale
  23. 23. Ratio ScaleThis scale consists not only of equidistant points but also has a meaningful zero pointmost sophisticated of scales, since it incorporates all the properties of nominal, ordinal and interval scales
  24. 24. Example(1) Temperature measured in degrees Kelvin is a ratio scale. because absolute zero = meaningful zero point0° K on the Kelvin scale = – 273.15 °C on the Celsius scale(2) If we ask 2 respondents their ages,difference between any two years would always be the same‘zero’ would signify the absence of age or birthHence, a 100-year old person is indeed twice as old as a 50- year old one.Sales figures, quantities purchased and market share are all expressed on a ratio scale.(4) most commonly when respondents are asked for their age, income, years of participation, etc.
  25. 25. ExerciseMention one variable for each of the four scales in the context of a market survey and explain how or why it would fit into the scale.
  26. 26. Rating ScalesDichotomous scale Elicits a Yes or No answer (nominal)Category scaleMultiple items to elicit a single response (nominal)Likert Scale Strong subjects on 5 pt scaleSD 1 D2 N3 A4 SA5
  27. 27. Semantic DifferentialBipolar attributes identified at extremes of the scale(interval)Responsive__ __ __ __ __ __ __UnresponsiveNumerical 5pt or 7pt scaleExtremely pleased 7 6 5 4 3 2 1Extremly DispleasedItemized rating scale : 5 or 7 pt scale. Balanced scale with a neutral point( unlikely & likely)
  28. 28.  Fixed or constant sum scaleChoosing the Toilet soap:1. Fragrance __2. Color __3. Shape __4. Size __5. Texture of Lather _______________________Total Points 100_____________________
  29. 29. Stapel Scale: Simultaneously measures direction and intensity (interval)Supervisor attributeThe picture of Sony TV is clear-5 -4 -3 -2 -1 clear +1 +2 +3 +4 +5Graphic Rating ScaleHow would you rate Sony TV on the following scale?(ordinal)Type I: Extremely bad_________________________Excellent
  30. 30. Consensus or Thurstone Equal Appearing Interval scaleMultidimensional scaling- conjoint analysis
  31. 31. Ranking ScalesOrdinal natureThey do not give definitive clues
  32. 32. Paired comparisonthe respondent is asked to select Aiwa Akai LG Sams Sony u one of two items as the n preferred or less preferred one g according to some criteria.Example – For each pair of TV Aiwa --- indicate which one would you Akai --- choose for your home viewing LG --- Sams --- u n g Sony ---
  33. 33. Forced ChoiceExample – Rank the following brands of TV as per your preference for home viewing (1 as the best and 5 as the worst).Aiwa _____Akai _____LG ____Samsung _____Sony ______
  34. 34. Comparative Scaledeals with direct comparison of objects or individualsdata collected is interpreted in relative termsdata have only ordinal or ‘rank’ characteristicsMore Useful About same Less Useful 1 2 3 4 5
  35. 35. Many changes continue to occur in the healthcare industry. Because of increasedcompetition for patients among providers and the need to determine how providers canbetter serve their clientele, hospital administrators sometimes mail a quality satisfactionsurvey to their patients after patient is released. The following types of questions aresometimes asked on such a survey. The questions will result in what level of datameasurement? 1. How long ago you were released from the hospital? 2. Which type of unit were you in for most of your stay? _Coronary Care _Intensive Care _Maternity Care 3. In choosing hospital, how important was the hospital’s location? Very Important, somewhat important, not very Important, not at all important 4. How serious was your condition when you were first admitted to the hospital? _critical _serious _Moderate _minor 5. Rate skill of the doctor: _excellent _very good _good _fair _poor 6. Rate one to seven on nursing care poor 1 2 3 4 5 6 7 excellent
  36. 36. Goodness of Measures Accurately measure Without redundancy Differentiate relevant and irrelevant things1. Reliability2. Validity
  37. 37. ReliabilityMeasures without bias, consistent across time and various items in instrumentTest-retest reliability (across time)Parallel-reliability( changes in wordings and sequence)Interitem Consistency Reliability (Cronbach’s Coefficient)Split-half reliability
  38. 38. ValidityAuthenticity of experimental designCause-effect relationships(internal)Generalizability(external)Content Validity(face validity)Criterion related(Concurrent& Predictive:difference is clear)Construct Validity(Convergent & Discriminant)
  39. 39. Thank you