Basic Statistics

1
Basic Statistics

• in Technology and Assessment

2
Levels of Measurement

• Ordinal Level
• Interval Level
• Nominal Level
• Ratio Level

3
Levels of Measurement (cont.)

• Nominal Level
• Simplest and least precise
• Differentiates attribute or property
• Little statistical value
• Examples
• Locker Number 20
• Social Security Number

4
Levels of Measurement (cont.)

• Ordinal Level
• Has the property of order (rank)
• Indicates difference (more or less)
• Indicates direction of difference
• Not mathematically meaning
• Examples
• Team rankings
• Class rankings

5
Levels of Measurement (cont.)

• Interval Level
• More precise measure calculations meaningful
• Provides equal difference in characteristic being
  assessed
• Zero point is arbitrary
• Example
• Temperature
• Cognitive Measures (i.e. -- I.Q. Test)

6
Levels of Measurement (cont.)

• Ratio Level
• Most precise and useful level
• Absolute zero
• Ratio number can make statements such as Twice
  as big/ .. Twice as fast
• Examples
• Distance throw
• Speed run

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Quiz....

1. Numbers on a football jersey.
2. Timed scores for 100 meter dash.
3. Mr. RU, first place runner up.
4. Gender classification for M/F.
5. Speedometer reading of 60 mph.
6. Temperature of 32 degrees
7. Wrestlers height and weight.

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Measures of Central Tendency

• Mode
• Score that occurs most often
• Median
• The point at which half the scores fall above and
  below
• Mean
• The numerical average.. The sum of the scores
  divided by N (the number of scores)

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Measures of Variability

• Range
• The difference between the highest score and
  lowest score
• Standard Deviation
• The most common measure of variability
• Spread of scores
• Amount each score deviates from the mean

10
Measure of Relationship

• Correlation
• You must have two sets of scores for each
  individual in order to use the correlation
• Identifies the direction and strength of the
  relationship between two sets of scores. The
  scores will range from 1.00 to 1.00

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Measure of Relationship (cont.)

• Direction
• The direction is identified by a or sign
• .. Both sets of scores have the higher score as
  the better score or lower score the better score.
• - .. One set of scores the higher score is
  better, the other set of scores the lower score

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Measure of Relationship (cont.)

• Examples of Direction of Relationship
• Twelve minute walk run to Shuttle Run
• Golf Score to Upper Body Strength
• Over GPA to Grade in Technology/Assess
• GPA to SAT
• Stress Test (high more stress) to Obesity (BMI
  higher means fatter)

13
Measure of Relationship (cont.)

• Strength (correlation coefficient)
• Number will range from 1.00 to .00
• The closer to one the number is the stronger the
  relationship
• Ranges
• .80 to 1.00 high correlation
• .60 to .79 moderately high correlation
• .49 to .59 moderate correlation
• .20 to .39 low correlation
• .00 to .19 no relationship

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Terminology

• Subjects
• People participating in your research project
• Variables
• What you are measuring speed, body composition,
  stress
• Test/Assessment
• The instrument you are using to collect the data
  in your research area.

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Terminology (cont.)

• Measurement
• The process/procedures used to collect the data
  (scores)
• Evaluation
• What you do with the information, what
  conclusion you reach once the data is analyzed,
  what action do you take?