AP Psych statistics Notes and flash cards 

Statistics: Away to organizes data and provide meaning

Descriptive: Organizing and summarizing

Inferential: Interpreting and drawing conclusions

Ways to portray data:

• Pie Charts

• Histogram/Bar Graph

  • Typically frequency as the Y axis
  • Topic of study as X axis

• Frequency polygon

  • Frequency is marked with a point on the graph (bell-shaped)
  • Typically frequency as the Y axis
  • Topic of study as X axis

  

Positively skewed distribution: A distribution with few HIGH scores

Negatively skewed distribution: A distribution with few LOW scores

Measures of central tendency:

Typical score in a distribution of numbers:

• Mode: the most frequent
• Median: the middle score, when scores and placed in order from least to most
• Mean: the average of all scores
  • The mean is not always the best summary of data

Measures of variability:

Variability: how much scores vary from each other from the MEAN

• Range: the difference between the lowest and highest scores
• Variance: This measures how different the scores are from each other
• Standard Deviation: gives the average distance scores are from the mean
  • The larger the deviation, the more spread out the scores

High variability: high standard deviation

Low variability: low standard deviation

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Statistical significance:

• The condition that exists when the probability that the findings are due to chance is less than 1 in 20 (p<.05)
• Results are likely due to manipulation of the independent variable and not due to random chance

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