METOPEN 6 Analysis Data [Compatibility Mode].

ANALYSIS AND
PRESENTATION OF DATA
Dr. Ratna Candra Sari
Email:
ratna_candrasari@uny.ac.id
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McGraw-Hill/Irwin

© 2003 The McGraw-Hill Companies, Inc.,All Rights Reserved.

Descriptive Statistics
• Distribution Descriptors
– Location
• Central Tendency
– Mean
– Median
– Mode

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Descriptive Statistics

• Distribution Descriptors
– Spread
• Variance,
• Standard Deviation,
• Range,
• Interquartile Range

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Descriptive Statistics
• Distribution Descriptors
– Shape
• Skewness
• Kurtosis

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Techniques to Display
and Examine Distributions
• Frequency Table

• Visual Displays
– Histograms

– Stem-and-leaf display
– Box-plot
• Crosstabulation of Variables

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• Research Without Hypothesis
• Research with Hypothesis

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Types of Hypotheses
• Null
– that no statistically significant difference
exists between the parameter and the
statistic being compared

• Alternative
– logical opposite of the null hypothesis
– that a statistically significant difference
does exist between the parameter and the
statistic being compared.
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Logic of Hypothesis Testing
• Two tailed test
– nondirectional test
– considers two possibilities

• One tailed test
– directional test
– places entire probability of an unlikely
outcome to the tail specified by the
alternative hypothesis

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Decision Errors in Testing
• Type I error
– a true null hypothesis is rejected

• Type II error
– one fails to reject a false null hypothesis

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Testing for Statistical Significance
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State the null hypothesis

Choose the statistical test
Select the desired level of significance
Compute the calculated difference value
Obtain the critical value
Interpret the test