PS11A PSYCHOLOGY LABORATORY AND METHODS: ABNORMAL, SOCAL AND DEVELOPMENTAL

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PS11A - PSYCHOLOGY LABORATORY AND METHODS
ABNORMAL, SOCAL AND DEVELOPMENTAL

• Charlene Coore
• 2006/2007

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Four Scales of measurement

• There are 4 scales/categories of measurement (a)
  nominal, (b) ordinal, (c) interval, (d) ratio.
• The scales of measurement will ultimately dictate
  the statistical procedures that you can use in
  processing the data.

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NOMINAL SCALE

• This is a scale of measurement that categorizes
  objects or individuals.
• The order of the categories is arbitrary or
  unimportant.
• Numbers, when used in a nominal scale, serve only
  as labels and provide no information on the
  magnitude or amount of the characteristic being
  measured.

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NOMINAL SCALE

• Female 1 Male 2.
• License plate numbers.
• Rural 1 or Urban 2

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ORDINAL SCALE

• A measurement scale in which objects or
  individuals are categorised and the order of the
  categories is important.
• The order of the categories reflects an increase
  in the amount of the characteristic being
  measured.
• The categories need not be of equal size.
• This scale allows us to rank-order our data. 

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ORDINAL SCALE

• Grades on a grading scheme A,B,C,D etc.
• 1st, 2nd 3rd in a race

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INTERVAL SCALE

• This is a measurement scale characterized by
  equal units of measurement throughout the scale.
  
• Measurements made on an interval scale provide
  information about both the order and the relative
  quantity of the characteristic being measured.
• There is no true zero value and so negative
  values are meaningful.

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INTERVAL SCALE

• A true zero means that none of the characteristic
  remains.
• Zero simply represents another point on the scale
  negative numbers are meaningful.
• Example Temperature 25C -10C

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RATIO SCALE

• This is a measurement scale that provides
  information about order.
• All units are of equal size throughout the scale,
  and there is a true zero value.
• The true zero allows ratios of values to be
  formed.
• Age is a ratio scale. Some one who is 40 is
  twice as old as someone who is 20!

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Summary
 
(Senders, 1958)
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Surveys

• Not as simple as they look
• Surveys can be conducted orally and in person,
  over the telephone or self-administered by the
  respondent in written format
• Particular types of surveys are better suited for
  gaining particular types of information.

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Mail Surveys

• Advantages
• Disadvantages
• Response rate is the extent to which people who
  receive a survey or are approached to complete an
  interview finishes the survey or interview.

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Group-Administered Surveys

• Surveys can also be given to a group of
  respondents in a classroom for example. This
  questionnaire should be enticing.
• The interviewer cannot clarify questions for
  individuals without weakening the validity of the
  study.

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Telephone Surveys

• Advantages
• Disadvantages

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Personal Survey

• The type of interview that involves a
  person-to-person meeting between the interviewer
  and respondent.
• This can be conducted anywhere 2 people can talk.
• Advantages
• Disadvantages

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Survey Construction

• Careful planning is necessary to develop a survey
  that will yield reliable and valid information.
• Layout of Questions
• Demographic Questions

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Survey Construction

• Wording of Questions
• Open Ended Survey, interview or test questions
  that do not provide specific options for answers
  but instead provide room/time for the respondent
  to formulate their own response.
• Advantages Allows the respondent more room to
  give complete info.
• Disadvantages It is hard to score!

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Survey Construction

• Close ended Survey, interview, or test
  questions that ask the respondent to choose from
  alternative potential answers.
• Advantages Easy to score
• Disadvantages alternatives that the respondent
  would have used may be omitted.

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Survey Construction

• Loaded Questions
• Do you think that the unstable quacks who believe
  in ESP should teach our children in schools?
• Do you think that people who believe in ESP
  should teach our children in schools?

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Survey Construction

• Leading Questions
• Most people with high IQs believe that we cannot
  be the only intelligent life in the universe Do
  you believe in aliens?
• Double-barreled Questions
• Do you believe in ghosts or aliens?
• Pilot Study