Subjectivity vs. Objectivity: Choosing the appropriate measurement

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Subjectivity vs. ObjectivityChoosing the
appropriate measurement

• R. Kevin Henry
• Psyc 562

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Outline

• What is objectivity and subjectivity?
• Objectivity the cornerstone of science
• Subjectivity the villain(?) of any study
• Objectivity and subjectivity as they apply to
  Human Factors
• Use of theories to aid selecting a measurement
• Generating good studies.
• Open discussion of the articles

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Our Duty and our Goal

• The human factors specialist isinterested in
  the performance of human operators as system
  components and wishes to know if the human
  improves or degrades the overall system
  performance. (Kantowitz and Sorkin, 1983)

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Philosophy and Psychology

• Both have dealt excessively with issues of
  subjectivity and objectivity.
• From Plato to Kant to Jean-Paul Sartre.
• Both are concerned with question of epistemology
  study of knowledge
• How do we know what we know?

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Objectivity

• Core belief Knowledge is external to the
  observer and must be pursued by eliminating
  subjectivity in all things.
• Free of bias, error, etc.
• Only data collected in an objective manner is
  worth looking at.
• With todays technology, this is becoming more of
  a possibility.
• High speed cameras, heart rate monitors, EEG, PET
  Scans, etc.

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Why Objectivity?

• Viewed as the cornerstone of science and
  scientific theory.
• Its tradition.
• Examples of objective data found in Human Factors
  
• Reaction time studies
• Heart Rate
• EEG
• Memory/Recall tests

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The Drawbacks of Objectivity

• The amount of data that can be objectively
  collected and quantified is limited.
• How do you quantify an Idea like Beauty, Justice,
  Love?
• It only presents a partial view of the subject
  being studied.

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Subjectivity

• Knowledge is determined by the observer
• Changed as it is assessed by each individual.
• Any external event is changed the minute it is
  perceived and changes according to that persons
  perception.
• Blind men describing the elephant. All of them
  thought they had the correct perception and thus
  the truth of what an elephant was.
• Heisenberg Uncertainty Principle

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Why Subjectivity?

• At times, It is the only measurement type
  available
• Beauty, Attractiveness, Attitude, Emotions, etc.
• It can help us form a more complete picture of
  the study, depending on the interest of the
  observer.

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The Human Element

• Subjectivity is impossible to get away from.
• From determining the test, analyzing the data,
  even setting up the criteria to be studied.
• The human element is present even in the most
  objective study conceived.
• Because of this, subjectivity should not be
  vilified, merely taken into account or even
  encouraged.

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Why Study Measurements?

• In Human Factors as a career, we will be expected
  to run studies and conduct research.
• Our understanding of how to design a study will
  be critical in yielding the proper results.

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Starting a Study

• To maximize effectiveness, we must take the
  proper steps in determining how the study should
  be set up.
• Look to the literature to see what studies have
  been done on your area of interest.
• Formulate your own theory.
• Select the proper measures.
• Collect Data
• Analyze Data
• Interpret Data
• Each step involves the human element.

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Key elements of any study

• Kantowitz (1992) notes that there are key
  elements to any measure
• Proper selection must take into consideration
  assigning values to objects Does it promote
  good representation? Does it have a uniqueness
  problem?
• Other issues
• Subject Representativeness
• Variable Representativeness
• Setting Representativeness

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Theories

• Kantowitz (1992) notes that having a Theory
  offers five benefits.
• It fills in where data is lacking.
• It can yield precise predictions, useful for
  engineers and designers.
• It prevents us from reinventing the wheel.
• It can offer a normative basis for human
  behavior.
• It is the best practical tool it can be used
  cheaply and efficiently.

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Theories cont.

• Each field of psychology has a set of theories
  that helps drive the discipline and the research
  it produces.
• Signal detection Theory Human Factors
• What other main Theories do we utilize?
• By using a theory as a starting off point, we can
  expect more robust results with a solid
  measurement aid.

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As Thoreau Said

• Simplify, Simplify. Theories help to reduce
  number of variables needed in a study by acting
  as a filter.
• The more complex a study, the higher a chance of
  missing important data or increasing error due to
  the human element.

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Mucklers Turn

• Muckler (1992) simplifies the process of
  selecting the appropriate measure by dividing it
  into two parts
• What has to be measured?
• How will that measurement be evaluated?
• (See Diagram on p. 450)

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The Ideal Measurement

• In all empirical disciplines, measurements must
  be developed and utilized in order to quantify
  data.
• More specifically, the ideal measure will reflect
  the overall system.
• The study must be designed to reflect as many
  variables as possible without becoming too
  complex to run.

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Objectivity is King -

• In all empirical sciences (our discipline
  included), the goal of all research is to obtain
  an objective measurement.
• What is an objective measurement? And why is this
  important?
• But is this even possible?

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Subjectivity the Villain?

• Any study that hinges upon the human element is
  bound to be declared a subjective study,
  implying that this type is somehow inferior.
• Example That study only used surveys with a
  Lickert Scale. It lacks any real objective
  data.
• Or worse, people quantify the Lickert scale as if
  it is ratio data.

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My argument

• Objectivity and Subjectivity are two sides to the
  same coin fact.
• Neither is necessarily superior, it only presents
  the data in a different manner.
• Arguing about which is better prevents many
  studies from even been conducted for fear of not
  being accepted.

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With that in mind

• How do we ensure that the studies that we set up
  are truly representative of the overall system
  and that our results can be generalized to the
  field?
• Do we fear subjectivity or allow it as a
  necessary evil? Or do we embrace its presence
  and utilize it to our advantage.

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Discussion

• What is the main focus of each article?
• What point does the author make that you agree
  with?
• What dont you agree with?
• Any visible flaws in their argument?
• Were these papers helpful?