descriptive statistics
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TRANSCRIPT
Descriptive Statistics
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What do you do with the data from your research?
• Present it visually– bar graphs, histographs
• Organize, summarize, and make inferences
What type of descriptive statistics are illustrated on the page?
Summarizing data use:
• Measures of Central Tendency– Mode- most frequent score– Mean- average of the scores– Median- the middle score
Important to ALWAYS check the range or scale of the graph. See book page 40 and 41
What type of Central Tendencies are used in each example?
• Measures of VariationThe amount of variation within data field– Range- low to high score
• Not so accurate
– Standard Deviation- how one score varies around the mean score
• Most accurate
Which Measure of Variation is used in these examples?
How do I know that any difference is reliable?
• Know what population is sampled
• Look for consistency
• More population the better
How do I know if there is a Statistical Difference?
• Are the sample averages reliable?
• Is the difference between them relatively large?
• Does it indicate the likelihood that the result happened by chance?
• Remember- that it does not indicate the importance of the result
Lab Assignment
• Find a graph in a current magazine or newspaper.• Analyze it and look for:
– How the ad is used (purpose)?
– What statistics are used to make a point?
– Who did the research?
– What other features are used to influence the reader?
– Type your answer and turn it in at your next class meeting.