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Introduction to Introduction to Behavioral StatisticsBehavioral Statistics
Introduction to Introduction to Behavioral StatisticsBehavioral Statistics
MeasurementMeasurement
The assignment of numerals to objects or The assignment of numerals to objects or events according to a set of rules. events according to a set of rules.
The rules used define or determine the The rules used define or determine the Level of MeasurementLevel of Measurement..
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Nominal Level of Measurement Ordinal Level of Measurement Interval Level of Measurement Ratio Level of Measurement
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Nominal Level of Measurement Ordinal Level of Measurement Interval Level of Measurement Ratio Level of Measurement
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Nominal Level of Measurement
The use of numbers or numerals as labels for a category ..
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Ordinal Level of Measurement
The use of numbers or numerals to indicate rank order.
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Interval level of Measurement
Interval scales have all of the propertiesInterval scales have all of the propertiesof ordinal scales, and in addition, equal of ordinal scales, and in addition, equal intervals on the scale of measurement intervals on the scale of measurement represent empirically equal intervals.represent empirically equal intervals.
Zero point is arbitary, Zero point is arbitary, notnot absolute! absolute!
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Interval level of Measurement
Interval scales have all of the propertiesInterval scales have all of the propertiesof ordinal scales, and in addition, equal of ordinal scales, and in addition, equal intervals on the scale of measurement intervals on the scale of measurement represent empirically equal intervals.represent empirically equal intervals.
Zero point is arbitary, Zero point is arbitary, notnot absolute! absolute!
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Ratio level of Measurement
Ratio level scales have all of the propertiesRatio level scales have all of the propertiesof interval scales and in addition have anof interval scales and in addition have anabsolute zero point.absolute zero point.
Ratios are equal throughout the scale.Ratios are equal throughout the scale.
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Ratio level of Measurement
Ratio level scales have all of the propertiesRatio level scales have all of the propertiesof interval scales and in addition have anof interval scales and in addition have anabsolute zero point.absolute zero point.
Ratios are equal throughout the scale.Ratios are equal throughout the scale.
MeasurementMeasurement:
Levels of MeasurementLevels of Measurement - -
Nominal Level of Measurement Ordinal Level of Measurement Interval Level of Measurement Ratio Level of Measurement
Frequency Distributions and Graphs
Exact Limits are from: 49.5 - 59.5Exact Limits are from: 49.5 - 59.5
Frequency Distributions & Frequency Distributions & GraphsGraphs
Conventions for Frequency Distributions
– No more than 20 or fewer than 10 class intervals.
– Preferred class interval sizes (1,2,3,5,10,15,20).
– Start grouping so that the lowest class interval is a multiple of the class interval size.
Frequency Distributions and Graphs
Histogram
IQ Test Results from 5th Grade Class
012345678
50-5960-6970-7980-8990-99100-109110-119120-129130-139140-149150-159
Frequency Distributions and Frequency Distributions and GraphsGraphs
IQ Test Results from 5th Grade Class
012345678
50-59
60-69
70-79
80-89
90-99
100-109
110-119
120-129
130-139
140-149
150-159
Rules for Constructing a Histogram– Plot the graph over the
actual class limits (Exact Upper & Lower)
– Plot the Dependent Variable on the ordinate
Frequency Distributions and Graphs
Line Graph/Frequency Polygon Line Graph/Frequency Polygon
IQ Results from 5th Grade Class
012345678
50-59
70-79
90-99
110-119
130-139
150-159
Frequency Distributions and Graphs
IQ Results from 5th Grade Class
012345678
50-59
70-79
90-99
110-119
130-139
150-159
Rules for Constructing a Frequency Polygon
– The point is placed over the mid-point of the class interval.
• Mid-point=UL-LL/2
– We assume that the interval above & below the highest and lowest class intervals are zero.
– To smooth a frequency polygon use:
• FS=X1+X2+X2+X3/4
– Start the Lowest class interval on the left side of the graph
Frequency Distributions and Graphs
IQ Results from 5th Grade Class
0 2 4 6 8
50-59
70-79
90-99
110-119
130-139
150-159
Frequency Distributions and Graphs
50-59
70-79
90-99
110-119
130-139
150-159
0
2
4
6
8
IQ Results from 5th Grade Class
Frequency Distributions and Graphs
50-59
70-79
90-99
110-119
130-139
150-159
0
2
4
6
8
IQ Results from 5th Grade Class
Frequency Distributions and Graphs
IQ Results from 5th Grade Class50-5960-6970-7980-8990-99100-109110-119120-129130-139140-149150-159
Frequency Distributions and Graphs
What can I learn from a graph?What can I learn from a graph?
Frequency Distributions and Graphs
Clustering of scores around some central value.
Knowledge of the dispersion of scores around a central point.
Symetry or lack of symetry (skewness) Flatness or steepness of a distribution
(Kurtosis) Whether or not the distribution is bimodal.
Frequency Distributions and Graphs
Clustering of scores around some central value.
Knowledge of the dispersion of scores around a central point.
Symetry or lack of symetry (skewness) Flatness or steepness of a distribution
(Kurtosis) Whether or not the distribution is bimodal.
Frequency Distributions and Graphs
This ends this unit! Please read the This ends this unit! Please read the section from your text discussing the section from your text discussing the use of the computer.use of the computer.
In our next unit, we will start putting In our next unit, we will start putting the peaces together by looking at the peaces together by looking at descriptive statistics……..descriptive statistics……..
Press Here toPress Here toReturn to classReturn to class
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Press Here toPress Here toReturn to classReturn to class
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