what is a number?
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What is a Number?. What is a number? Names and symbols are arbitrary. What is a number? Names and symbols are arbitrary. Four…. IV …. 4…. What is a number? Names and symbols are arbitrary. Numbers that are not numbers…. 0. http://en.wikipedia.org/wiki/0_%28number%29. - PowerPoint PPT PresentationTRANSCRIPT
What is a Number?
What is a number?Names and symbols are arbitrary.
What is a number?Names and symbols are arbitrary.
Four…. IV …. 4….
What is a number?Names and symbols are arbitrary.
Numbers that are not numbers….
0
http://en.wikipedia.org/wiki/0_%28number%29
Numbers that are not numbers…Some make the world go around.
e
What is a number?Names and symbols are arbitrary.
Measurement:
“Rules for assigning numbers to objects (or concepts) to represent quantities of attributes.”
What is a number?Names and symbols are arbitrary.
Measurement:
What is a number?Names and symbols are arbitrary.
But to be a true number scale the symbolsmust follow some logical
and systematic arrangement.
What is a number?Names and symbols are arbitrary.
Measurement:
“Standardized process of assigning symbols to objects according to certain prespeciified and
nondegenerating rules.”
Is it possible to have an IQ of 160? But what does it mean?
160
What is a number?Names and symbols are arbitrary.
Measurement:
What is a number?Names and symbols are arbitrary.
Measurement:
“An object is never measured… only theobject’s attributes.”
What is a number? Object characteristics.
What is a number?
Scales:
“A scale is the continuum upon which measurements are located.”
Zero degreescentigrade….
So then what is this…..
What is a number?
Scales:
Likert Scale
Ice cream is good for breakfast.1. Strongly disagree 2. Disagree 3. Neither agree nor disagree 4. Agree 5. Strongly agree
What is a number?
Scales:
Likert Scale
What is a number?
Scales:
Likert Scale
What is a number?
Scales: Likert
What is a number?
Scales:
What is a number?
Scales:
What is a number?
Semanticscales:
What is a number?
Scales:
What is a number?
Scales:
What is a number?
But complex concepts in businessmay not be easily measured.
What is a number?
But complex concepts in businessmay not be easily measured.
Harvard professor S.S. Stevenscreated scales to measure difficult
concepts.
Stevens’ Scales
Steven’s original paper in Science, 103(2684), June 7, 1946.
Steven’s Scales:
Ratio
Steven’s Scales: 1. Nominal Scales
Steven’s Scales: 1. Nominal Scales
a. Name
Steven’s Scales: 1. Nominal Scales
a. Nameb. Classify
Steven’s Scales: 1. Nominal Scales
a. Nameb. Classify
c. Categorize
Steven’s Scales: 1. Nominal Scales
a. Nameb. Classify
c. Categorize
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales
Does everything a nominal scales does.Ranks objects or concepts by some
characteristic.
http://www.usatoday.com/sports/sagarin/fbt09.htm
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales 3. Interval scales
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales 3. Interval scales
Does everything an ordinal scale does.
Interval is now meaningful.
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales 3. Interval scales4. Ratio scales
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales 3. Interval scales4. Ratio scales
Has all the characteristics of all other scales, but it also has meaningful ratios. It has a true zero.
http://www.fao.org/docrep/W3241E/w3241e04.htm
Good source:
Steven’s Scales: 1. Nominal Scales2. Ordinal Scales X = f(x)3. Interval scales X = kx + c4. Ratio scales X = kx
Which scale to use?1. Amount of information needed
Which scale to use?1. Amount of information needed Each higher scale carries more information than the one before it.
Which scale to use?1. Amount of information needed2. Characteristics of stimulus or concept
Which scale to use?1. Amount of information needed2. Characteristics of stimulus or concept3. Application context
Which scale to use?1. Amount of information needed2. Characteristics of stimulus or concept3. Application context4. Capacity of scale
Which scale to use?1. Amount of information needed2. Characteristics of stimulus or concept3. Application context4. Capacity of scale5. Post-measurement analysis
Which scale to use?1. Amount of information needed2. Characteristics of stimulus or concept3. Application context4. Capacity of scale5. Post-measurement analysis
Statistics are designed for specific typesof scales. Using the wrong scale will giveanswers that are nonsense.
Measurement characteristics:
Measurement characteristics:
Y = x(true) + x(sy-error) + x(random)
Measurement characteristics:
Y = x(true) + x(sy-error) + x(random)
Systematic error can be eliminated.
Measurement characteristics:
Y = x(true) + x(sy-error) + x(random)
Random error cannot be eliminated.
Measurement characteristics:
Y = x(true) + x(sy-error) + x(random)
If a sample is taken to estimate an answer:another form of error is added……
Measurement characteristics:
This is called a Sampling Error
Y = x(true) + x(sy-error) + x(random) + x(sampling error)
You and a friend (in the same class) take thesame exam at the same time and
get different grades.
WHY?
Measurement characteristics:Validity
Measurement characteristics:Validity1. Face
Measurement characteristics:Validity1. Face2. Content
Measurement characteristics:Validity1. Face2. Content3. Criteria
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
4. Construct
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
4. Construct
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
4. Constructa. Convergent
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
4. Constructa. Convergent
b. Divergent
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
4. Constructa. Convergent
b. Divergentc. Discriminant
Measurement characteristics:Validity1. Face2. Content3. Criteria
a. Concurrentb. Predictive
4. Constructa. Convergent
b. Divergentc. Discriminant
d. Nomological
Measurement characteristics:Reliability
Measurement characteristics:Reliability1. Stability
Measurement characteristics:Reliability1. Stability
a.Test-retestb. Equivalent forms
Measurement characteristics:Reliability1. Stability
a.Test-retestb. Equivalent forms
2. Equivalence
Measurement characteristics:Reliability1. Stability
a.Ttest-retestb. Equivalent forms
2. Equivalence a. Kuder-Richardsonb. Cronbach’s Alpha
Measurement characteristics:Reliability1. Stability
a.Test-retestb. Equivalent forms
2. Equivalence a. Kuder-Richardsonb. Cronbach’s Alpha
Lee Cronbach
Measurement characteristics:Reliability1. Stability
a.Test-retestb. Equivalent forms
2. Equivalence a. Kuder-Richardsonb. Cronbach’s Alpha
Learn, Effective, & Like the instructor
Measurement characteristics:Reliability1. Stability
a.Test-retestb. Equivalent forms
2. Equivalence a. Kuder-Richardsonb. Cronbach’s Alpha
3. Inter-rater Consistencya. Krippendorff’s Alpha