Week 8 Prac

1
Week 8 Prac

• Introduction to SPSS

2
Location of Files

• The files are saved on the sbsrvr server on the
  folder temp\mktg222
• The temp is a mapped drive on the server sbsrvr
• PSYCH, QUEST92, SET93

3
Accessing an Existing Data File

• Select FILE on the menu bar at the top of the
  screen
• Point to the word OPEN appears to the side
• Click once on the word DATA
• We are interested in the file quest92.sav so
  double click on this name
• Each column represent a different variable and
  each row represents a different subject.
• So, for example, the second subject has an id of
  19, is aged 22, has sex coded 1 etc

4
Exercise

• What is the age and identification number for
  subject number 5?
• Ans. Subject number 5 has an id of 21 and is 20
  years old
• Note that sex is given a numerical code of either
  1 or 0, rather than F for female and M for males.
  This is common practice when computer packages,
  such as SPSS are used to analyze data.

5
Examining labels using Utilities

• Select Utilities on the menu bar at the top of
  the screen
• Click once on the word Variables opens variable
  information window
• The variables are listed in alphabetical order on
  the left hand side
• On the right hand side is information about
  whichever variable is highlighted

6
Exercise

• Use the Utilities menu to get information on the
  variables pulse, relig and weight.
• What do each of these variables represent
• How are they recorded (for example, is weight
  measured in categories light, medium,
  heavy, or is it recorded as a continuous value,
  say 56)
• What is the missing value code
• Are there any category labels and if so, what are
  they
• Case number 3 you will see that tvhours has a .
  Rather than a number. This symbol is the system
  missing value.

7
Levels of Measurement

• Nominal figurative labeling scheme in which the
  numbers serve only as labels or tags for
  identifying and classifying objects. Used for
  identifying respondents, brands, attributes,
  stores and other objects.
• Ordinal a ranking scale in which numbers are
  assigned to objects to indicate the relative
  extent to which the objects posses some
  characteristics. Used to measure attitudes,
  opinions, perceptions, and preferences.
• Interval numerically equal distances on the
  scale represent equal values in the
  characteristic being measured. E.g. temperature,
  age, weight

8
Levels of Measurement

• What is the level of measurement of the variables
  pulse, relig, and weight?
• What is the level of measurement of the variables
  trnsport, tvhours and enjoy?
• Categorical data will refer to variables which
  take just a limited number of categories.
• Metric data will refer to variables which are
  measured on an interval scale and take many
  different values.

9
Exercise

• In the quest92.sav data file
• Is enjoy metric or categorical?
• Is weight metric or categorical?
• Name three other metric variables?
• Name three other categorical variables