Lecture 6 Flashcards
What are the 4 scales you know?
- Nominal
- Ordinal
- Interval
- Ratio
Explain the nominal scale and give an example and which test is used to analyse them.
Numbers are assigned to specific participant.
Numbers serve only as labels or tags for identifying and classifying objects.
When used for identification, there is a strict one-to-one correspondence between the numbers and the objects.
Numbers do not reflect the amount of the charasteritic possessed by the objects
Only permissible operation on the numbers in a nominal scale os counting.
Only a limited number os statistics, all of which are based on frequency counts, are permissible, e.g. percentages
Student Regsitration Numbers
Gender Classification
Chi-Square Test
Explain the ordinal scale and give an example and which test is used to analyse them.
Rank order of winners.
A ranking scale in which numbers are assigned to objects to indicate the realtive extent to which the bjects possess some characteristics
Can determine wheteher an object has more or less of characterstits than some other object, but now how much more or less
Any series of numbers can be assigned that preserves the ordered relationship between the objects
In addition to the counting operatin allowable for nominal scale data, ordinal scales permit the use of statistics based on centiles, e.g. percentile, median
Football World Rankings
Rank oder of favorite TV programmes
ANOVA
Explain the interval scale and give an example and which test is used to analyse them.
Performace rating on a 0 to 10 basis
Numerically equal distances on the scale represent equal values in the characteristic being measured
It permits comparison of the difference between objects
The location of the zero point it not fixed. Both the zero point and the units of measurement are arbitrary
Any positive linear tranformation of the form y=a+bx will preserve the properties of the scale
It is not meaningful to take ratios of scale value
Statistical technique that may be used to include all of these that can be appied to nomian and ordinal data in addition the arithmetic mean, standard deviaton and other
Attituded, opinions, index numbers
Temperature
ANOVA
Explain the Ratio scale and give an example and which test is used to analyse them.
Posseses all the properties of the nominal, ordinal and interval sclaes
It has an absolute zero point
It is meaningful to compute ratios of sclae values
Only proportionate transformations of the form y=bx, where b is a positiv constant, are allowed
All Statistical techniques can be applied
Age, Income
Coefficent of variation
Explain comparative and non-comparative scales
Comparative:
Involve the direct comparison of stimulus objects
Comperative scale data must be interpreted in relative terms and have only ordinal or rank order properties
Non-Comparative:
Each Object is scaled independently of the others in the stimulus set
Resulting data are generally assumed to be interval or ratio scaled
What are the advantages and disadvantages of comparative scales?
Advantages:
- Small differences between stimulus objects can be detected
- Same known reference points for all respondents
- Easily Understood and can be applied
- Involve fewer theoretical assumptions
- Tend to reduce halo or carryover effect from one judgement to another
Disadvantages:
- Ordinal Nature of the data
- Inability to generalize beyond the stimulus
- Obects scaled
Which different comparassion scales do you know?
- Paired Comparison
- Rank Order
- Sum Scaling
What are some basic non-comparative scales?
- Continuous rating Scale
Place a mark on a continuous line
+easy
-scoring can be awkward
- Likert Scale
Degree of agreement and disagreement
+easy to conduct
-more time
- Sematic differntial Scale
Seven Point Scalre with bipolar labels
+verstatile
-controversy as to whether the data are interval
- Stapel Scale
Unipolar 10-Point scale, -5 to +5, withoout a neutral point
+easy to construct
-confusing and difficualt to apply
Development of a multi item scale
Look paper
