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Measurement
Measurement
• The process of assigning numbers or labels to units of analysis in order
to represent conceptual properties....
Cont.…
• The ultimate goal of measurement is to specify
clearly observable referents of the terms contained
in one’s hypot...
Conceptualization
• Initial step is to clarify the concepts
embedded in one’s hypothesis with words
and examples.
• Proces...
Cont.…
• The conceptualization of complex concepts such as social capital
often requires careful distinctions among simila...
Operationalization
• Once the meaning of the concept is clarified and
the concept is constructed as variable, the process
...
Cont.…
• While creating operational definitions, a researcher may
consider many different empirical representations or
ind...
Cont.…
• Indicators provide imperfect representations of the
concepts for two reasons:
- Indicators often contain errors o...
Cont.…
Operationalizing the concept of religiosity
• My religious beliefs are what really lie behind my
whole approach to ...
Verbal reports
• Self reports provide simple and generally accurate
measures of background variables such as age,
gender, ...
Cont…
• There are numerous composite measures of
prejudice, combining from two to twenty
questions or more-
• Do you think...
Cont…
• Observation: observation provides direct and
generally unequivocal evidence of overt behavior,
but it also is used...
Level of measurement
• Nominal
• Ordinal
• Interval
• Ratio
Nominal measurement
• System in which cases are classified into two or more
categories on some variable, such as gender, r...
Ordinal Measurement
• In ordinal measurement, number indicate only the rank order of cases on some
variable.
• Ordinal mea...
• In the realm of social measurement one can
probably say with some certitude whether security
or chance for advancement i...
Interval measurement
• Interval measurement has the quality of the nominal
and ordinal levels, plus the requirement that e...
• Though interval measurement system does not have
absolute zero that is it is not a fixed but an arbitrary
point.
• There...
Ratio Measurement
• Includes the feature of other levels plus an
absolute zero point.
• The presence of an absolute zero m...
Information provided by the four
levels of measurement
Information
provided
Nominal Ordinal Interval Ratio
Classification ...
Reliability and validity
• Reliability is concerned with questions of stability
and consistency.
• An ex. of a highly reli...
Cont…
• Measurement validity refers to the extent of
matching, congruence, or goodness of fit between
an operational defin...
Sources of error
Observed value= true value + systematic error+
random error
The first source of variation is true differe...
Cont…
• Systematic measurement error results from the
factors that systematically influence either the
process of measurem...
Cont…
• Random measurement error is unrelated to
true differences in the concept being
measured. It is the result of tempo...
Reliability assessment
• Reliability indicates consistency, or the extent to
which a measure does not contain random error...
Cont…
Low reliability High reliability High reliability
Low validity Low validity High validity
High random error Low rand...
Split half and internal consistency
reliability
• The second set of procedures for assessing
reliability estimates the agr...
Validity assessment
• Reliability assessment is relatively simple, validity
assessment by contrast is more problematic.
• ...
Subjective validation
• Face validity: refers simply to a personal judgment
that an operational definition appears, on the...
Thank you
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Research methodology measurement

It is about measurement of research methodology.

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Research methodology measurement

  1. 1. Measurement
  2. 2. Measurement • The process of assigning numbers or labels to units of analysis in order to represent conceptual properties. • The measurement process begins with formulation of research problem or hypothesis. • Every research problem contains terms – concepts or variables.
  3. 3. Cont.… • The ultimate goal of measurement is to specify clearly observable referents of the terms contained in one’s hypothesis. • Thus, the entire measurement process consists of moving from the abstract (concepts) to the concrete (measures of the concept.
  4. 4. Conceptualization • Initial step is to clarify the concepts embedded in one’s hypothesis with words and examples. • Process of formulating and clarifying concepts is called conceptualization. It is linked to theory testing and construction. • The conceptualization is an ongoing process that may occur prior to any particular empirical investigation and is usually continues through research as theories and their constituent concepts are refined and elaborated.
  5. 5. Cont.… • The conceptualization of complex concepts such as social capital often requires careful distinctions among similar ideas and breaking down the concept into various components or dimensions. • Measurement assumes the possibility of assigning different values or categories to unit of analysis; hence, we measure concepts tat vary, which we refer to as variables. • However, many social science concepts like social capital, or wealth etc are not directly measurable. These are rather manifestation of several directly measurable variables. After conceptualization , the next step is to identify such manifestations of one’s concepts.
  6. 6. Operationalization • Once the meaning of the concept is clarified and the concept is constructed as variable, the process of operationalization of the measurement process begins. • First step of the operationalization is to set up an operational definition as a counterpart of conceptual definition that corresponds reasonably good to the concept in question. • An operational definition describes the research operation that will specify the value and category of the variable on each case.
  7. 7. Cont.… • While creating operational definitions, a researcher may consider many different empirical representations or indicators. • An indicator consists of a single observable measure, such as a single questionnaire item in the survey. • No two indicators measure a given concept or variable in the same way, and no one indicator is likely to correspond perfectly to its underlying concept.
  8. 8. Cont.… • Indicators provide imperfect representations of the concepts for two reasons: - Indicators often contain errors of classification - Indicators rarely capture all the meaning of a concept. • Because of the imperfect correspondence between indicators and concepts, researchers often choose to rely on more than one indicator when operationalizing a concept.
  9. 9. Cont.… Operationalizing the concept of religiosity • My religious beliefs are what really lie behind my whole approach to life. (1) this is definitely not so (2) Probably not so (3) Probably so (4) definitely so.
  10. 10. Verbal reports • Self reports provide simple and generally accurate measures of background variables such as age, gender, marital status and education. • Composite measures: in self report attitude measurement, responses to several questions frequently are combines to create and index or scale.
  11. 11. Cont… • There are numerous composite measures of prejudice, combining from two to twenty questions or more- • Do you think there should be laws against marriages between blacks and whites? Yes/no • White people have the right to keep blacks out of their neighborhoods if they want to, and black should respect that right. Do you agree strongly, agree slightly, disagree slightly, or disagree strongly with this statement
  12. 12. Cont… • Observation: observation provides direct and generally unequivocal evidence of overt behavior, but it also is used to measure subjective experience such as feelings and attitudes. • Archival records: which refers to existing recorded information, provide another invaluable source of measurement.
  13. 13. Level of measurement • Nominal • Ordinal • Interval • Ratio
  14. 14. Nominal measurement • System in which cases are classified into two or more categories on some variable, such as gender, race, religious preference etc. • In nominal measurement numbers (more accurately numerals) are assigned to the categories simply as labels or codes for the researcher’s convenience in collecting and analyzing the data. • Categories of the variable should possess two characteristics: they must be exhaustive and mutually exclusive.
  15. 15. Ordinal Measurement • In ordinal measurement, number indicate only the rank order of cases on some variable. • Ordinal measurement allows the researchers to make an accurate judgment about one thing compared to another, even when they can not make an accurate absolute judgment. Ex.: Individual’s ranking of certain leisure activities in terms of the pleasure derived from them. The three activities are ranked as: 1.Playing tennis 2.Watching television 3. Reading sociology , where one, two and three represent individuals’ ranking of the leisure activities
  16. 16. • In the realm of social measurement one can probably say with some certitude whether security or chance for advancement is the more important job characteristic, without being able to say how important either characteristic is. • The ability of human observers to make such comparative judgments permits a wide range of reasonably accurate social measurements at the ordinal level. For example, measures of socioeconomic status, intelligence etc. Cont.…
  17. 17. Interval measurement • Interval measurement has the quality of the nominal and ordinal levels, plus the requirement that equal distances or intervals between numbers represents equal distances in the variable being measured. • For Ex. Fahrenheit temperature scale: the difference between 20ºF and 30ºF is the same as the difference between 90ºF and 100ºF- 10ºF. We can infer not only that 100ºF is hotter than 90ºF but also how much it is.
  18. 18. • Though interval measurement system does not have absolute zero that is it is not a fixed but an arbitrary point. • Therefore, we can not say that 100ºF is twice as hot as 50ºF as it will require a fixed zero point which interval measurement system does not have. Cont.…
  19. 19. Ratio Measurement • Includes the feature of other levels plus an absolute zero point. • The presence of an absolute zero makes it possible to multiply or divide scale numbers meaningfully and thereby form ratios. • Ex. Rs. 10000 and Rs. 20000, one can divide the other
  20. 20. Information provided by the four levels of measurement Information provided Nominal Ordinal Interval Ratio Classification X X X X Rank Order X X X Equal Intervals X X Non arbitrary Zero X
  21. 21. Reliability and validity • Reliability is concerned with questions of stability and consistency. • An ex. of a highly reliable measuring instrument is a steel tape measure. A cloth tape measure would be somewhat less reliable. • SRS data is reliable. • Unreliable things cannot be valid.
  22. 22. Cont… • Measurement validity refers to the extent of matching, congruence, or goodness of fit between an operational definition and the concept it is purported to measure. • Ex. Amniocentesis, it is a valid measure of biological sex which can determine with virtually perfect accuracy.
  23. 23. Sources of error Observed value= true value + systematic error+ random error The first source of variation is true differences in the concept the operation is intended to measure. Ex. IQ test ought to reflect only true differences in intelligence and nothing else.
  24. 24. Cont… • Systematic measurement error results from the factors that systematically influence either the process of measurement or the concept being measured. • When the respondent’s sensitivity or responsiveness to a measure is affected by the process of observation or measurement, we refer to this a s a reactive measurement effect.
  25. 25. Cont… • Random measurement error is unrelated to true differences in the concept being measured. It is the result of temporary, chance factors. • Ex. A tired and bored respondent may give erroneous responses by not attending carefully to the questions asked. • Similarly an ambiguously worded question will produce random errors by eliciting responses that vary according to respondent’s interpretation of the question’s meaning. • Such a error is random because its presence, extent and direction are unpredictable.
  26. 26. Reliability assessment • Reliability indicates consistency, or the extent to which a measure does not contain random error. • Test retest reliability: the procedure involves testing the same persons or units on two separate occasions.
  27. 27. Cont… Low reliability High reliability High reliability Low validity Low validity High validity High random error Low random error Low random error Low systematic error High systematic error Low systematic error
  28. 28. Split half and internal consistency reliability • The second set of procedures for assessing reliability estimates the agreement or equivalence among the constituent parts or items of a multi- item measure. • Ex. Age of women and age at marriage.
  29. 29. Validity assessment • Reliability assessment is relatively simple, validity assessment by contrast is more problematic. • Systematic errors which affect validity but not reliability, are more difficult to detect than random errors. • The issue of measurement validity generally cannot be divorced from larger theoretical concerns.
  30. 30. Subjective validation • Face validity: refers simply to a personal judgment that an operational definition appears, on the face of it, to measure the concept it is intended to measure. • Content validity: concerns the extent to which a measure adequately represents all facets of a concept.
  31. 31. Thank you

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